Hemisphere GPS Technical Reference v1.02

Hemisphere GPS Technical Reference v1.02
Hemisphere GPS Technical Reference v1.02
Table Of Contents
Introduction .............................................................................................................................................13
GPS Technology and Platforms..............................................................................................................14
GPS Engine..........................................................................................................................................................15
GPS Engine Overview ...................................................................................................................................................... 15
Satellite Tracking .............................................................................................................................................................. 15
Positioning Accuracy ........................................................................................................................................................ 15
Update Rates.................................................................................................................................................................... 16
DGPS Solutions ...................................................................................................................................................17
COAST Technology.......................................................................................................................................................... 17
SBAS - Overview .............................................................................................................................................................. 18
EGNOS............................................................................................................................................................................. 22
MSAS ............................................................................................................................................................................... 22
GAGAN............................................................................................................................................................................. 23
Radiobeacon..................................................................................................................................................................... 23
OmniSTAR........................................................................................................................................................................ 25
Crescent Base Station Operation ..................................................................................................................................... 28
e-Dif - Extended Differential Option for the Crescent Receiver ...........................................................................29
e-Dif Rover Mode Operation ............................................................................................................................................. 30
e-Dif Startup...................................................................................................................................................................... 30
e-Dif Rover Calibration ..................................................................................................................................................... 30
e-Dif Rover Performance .................................................................................................................................................. 30
L-Dif - Local Differential Option ............................................................................................................................31
L-Dif Startup...................................................................................................................................................................... 31
L-Dif Performance............................................................................................................................................................. 31
RTK Overview ......................................................................................................................................................31
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Post Processing ...................................................................................................................................................31
Hemisphere GPS Hardware Platforms ................................................................................................................32
Crescent Vector OEM Development Kit............................................................................................................................ 32
Evaluating Receiver Performance........................................................................................................................33
Receiver Operation .................................................................................................................................35
Receiver Operation Overview ..............................................................................................................................35
Communicating with the Receiver........................................................................................................................35
Communicating with Receivers......................................................................................................................................... 35
NMEA 0183 Messages ..................................................................................................................................................... 35
Hemisphere GPS Proprietary Binary Interface ................................................................................................................. 36
RTCM SC-104 Protocol .................................................................................................................................................... 37
Firmware and Subscription Codes .......................................................................................................................38
Firmware........................................................................................................................................................................... 38
Subscription Codes........................................................................................................................................................... 42
Configuring the Receiver......................................................................................................................................55
Configuring the Data Message Output.................................................................................................................56
Saving the Receiver Configuration.......................................................................................................................57
Using Port D for RTCM Input ...............................................................................................................................57
SBX-4 Database Mode.........................................................................................................................................58
PocketMAX Utility ...................................................................................................................................59
PocketMAX Overview...........................................................................................................................................59
PocketMAX Key Uses ..........................................................................................................................................60
PocketMAX Startup ..............................................................................................................................................60
PocketMAX Features ...........................................................................................................................................61
PocketMAX GPS Tabs ..................................................................................................................................................... 61
Differential Source Tabs ................................................................................................................................................... 61
TMNL Tabs ....................................................................................................................................................................... 62
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LOGS Tabs....................................................................................................................................................................... 63
HDG Tabs......................................................................................................................................................................... 63
Commands and Messages .....................................................................................................................65
NMEA 0183 Message Format..............................................................................................................................66
Command/Query/Message Types .......................................................................................................................67
General Operation and Configuration Commands............................................................................................................ 67
GPS Commands............................................................................................................................................................... 69
SBAS Commands............................................................................................................................................................. 69
e-Dif Commands............................................................................................................................................................... 69
Crescent Vector Commands and Messages .................................................................................................................... 70
GLONASS Commands and Messages............................................................................................................................. 72
DGPS Base Station Commands ....................................................................................................................................... 73
Local Differential and RTK Commands and Messages .................................................................................................... 73
Beacon Receiver Commands and Messages ................................................................................................................... 74
NMEA 0183 SBX Queries................................................................................................................................................. 75
OmniSTAR Commands .................................................................................................................................................... 75
RAIM Commands ............................................................................................................................................................. 77
Data Messages................................................................................................................................................................. 77
Binary Messages .............................................................................................................................................................. 78
NMEA 2000 CAN Messages ............................................................................................................................................ 79
Commands (All)....................................................................................................................................................80
GPCRQ,MSK Command .................................................................................................................................................. 80
GPCRQ,MSS Command .................................................................................................................................................. 81
GPMSK Command ........................................................................................................................................................... 82
JAGE Command............................................................................................................................................................... 84
JAIR Command ................................................................................................................................................................ 85
JALT Command................................................................................................................................................................ 87
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JAPP Command ............................................................................................................................................................... 89
JASC Command Overview ............................................................................................................................................... 91
JASC,CMR Command...................................................................................................................................................... 92
JASC,D1 Command ......................................................................................................................................................... 93
JASC,DFX Command....................................................................................................................................................... 94
JASC,GL Command ......................................................................................................................................................... 95
JASC,GN Command......................................................................................................................................................... 96
JASC,GP Command......................................................................................................................................................... 97
JASC,INTLT Command .................................................................................................................................................... 99
JASC,PASHR Command................................................................................................................................................ 100
JASC,PSAT,RTKSTAT Command ................................................................................................................................. 102
JASC,PTSS1 Command................................................................................................................................................. 103
JASC,ROX Command .................................................................................................................................................... 105
JASC,RTCM Command.................................................................................................................................................. 106
JASC,RTCM3 Command................................................................................................................................................ 107
JASC,VIRTUAL Command ............................................................................................................................................. 108
JATT Command Overview.............................................................................................................................................. 109
JATT,CSEP Command................................................................................................................................................... 110
JATT,COGTAU Command ............................................................................................................................................. 111
JATT,EXACT Command................................................................................................................................................. 112
JATT,FLIPBRD Command ............................................................................................................................................. 113
JATT,GYROAID Command ............................................................................................................................................ 114
JATT,HBIAS Command.................................................................................................................................................. 115
JATT,HELP Command ................................................................................................................................................... 116
JATT,HIGHMP Command .............................................................................................................................................. 117
JATT,HRTAU Command ................................................................................................................................................ 118
JATT,HTAU Command................................................................................................................................................... 119
JATT,LEVEL Command ................................................................................................................................................. 120
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JATT,MSEP Command .................................................................................................................................................. 121
JATT,NEGTILT Command ............................................................................................................................................. 122
JATT,NMEAHE Command ............................................................................................................................................. 123
JATT,PBIAS Command .................................................................................................................................................. 124
JATT,PTAU Command ................................................................................................................................................... 125
JATT,ROLL Command ................................................................................................................................................... 126
JATT,SEARCH Command.............................................................................................................................................. 127
JATT,SPDTAU Command .............................................................................................................................................. 128
JATT,SUMMARY Command .......................................................................................................................................... 129
JATT,TILTAID Command ............................................................................................................................................... 131
JATT,TILTCAL Command .............................................................................................................................................. 132
JBAUD Command .......................................................................................................................................................... 133
JBIN Command .............................................................................................................................................................. 135
JBOOT,OMNI Command ................................................................................................................................................ 137
JCONN Command.......................................................................................................................................................... 138
JDIFF Command ............................................................................................................................................................ 139
JDIFFX,EXCLUDE Command ........................................................................................................................................ 141
JDIFFX,GNSSOUT Command ....................................................................................................................................... 142
JDIFFX,INCLUDE Command ......................................................................................................................................... 144
JDIFFX,SOURCE Command.......................................................................................................................................... 145
JDIFFX,TYPE Command................................................................................................................................................ 146
JFLASH Command Overview ......................................................................................................................................... 147
JFLASH,DIR Command.................................................................................................................................................. 148
JFLASH,FILE,CLOSE Command ................................................................................................................................... 149
JFLASH,FILE,NAME Command ..................................................................................................................................... 150
JFLASH,FILE,OPEN Command ..................................................................................................................................... 151
JFLASH,FREESPACE Command .................................................................................................................................. 152
JFLASH,NOTIFY,CONNECT Command ........................................................................................................................ 153
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JFLASH,QUERYCONNECT Command ......................................................................................................................... 154
JFREQ Command .......................................................................................................................................................... 155
JGEO Command ............................................................................................................................................................ 157
JHP Command Overview ............................................................................................................................................... 159
JHP,LIMIT Command ..................................................................................................................................................... 160
JHP,MODE,AUTOSEED Command ............................................................................................................................... 161
JHP,MODE,IGNORECONV Command .......................................................................................................................... 162
JHP,POS Command....................................................................................................................................................... 163
JHP,POS,LAT,LON,HGT Command .............................................................................................................................. 164
JHP,POS,LAT,LON,HGT,,,,OTHER Command .............................................................................................................. 165
JHP,POS,OTHER Command ......................................................................................................................................... 166
JHP,POS,PRESENT Command ..................................................................................................................................... 167
JHP,RESET,ACCURACY Command ............................................................................................................................. 168
JHP,RESET,ENGINE Command.................................................................................................................................... 169
JHP,SEED Command..................................................................................................................................................... 170
JHP,SEED,LAT,LON,HGT Command ............................................................................................................................ 171
JHP,STATIC Command.................................................................................................................................................. 172
JHP,STATUS,AUTOSEED Command............................................................................................................................ 173
JI Command ................................................................................................................................................................... 174
JK Command .................................................................................................................................................................. 175
JLBEAM Command ........................................................................................................................................................ 177
JLIMIT Command ........................................................................................................................................................... 179
JLXBEAM Command...................................................................................................................................................... 180
JMASK Command .......................................................................................................................................................... 182
JMODE Overview ........................................................................................................................................................... 183
JMODE Command.......................................................................................................................................................... 184
JMODE,FOREST Command .......................................................................................................................................... 185
JMODE,GPSONLY Command ....................................................................................................................................... 186
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JMODE,L1ONLY Command ........................................................................................................................................... 187
JMODE,MIXED Command ............................................................................................................................................. 188
JMODE,NULLNMEA Command ..................................................................................................................................... 189
JMODE,SBASR Command ............................................................................................................................................ 190
JMODE,TIMEKEEP Command....................................................................................................................................... 191
JMODE,TUNNEL Command .......................................................................................................................................... 192
JMSG99 Command ........................................................................................................................................................ 193
JNMEA,GGAALLGNSS Command................................................................................................................................. 194
JNMEA,PRECISION Command ..................................................................................................................................... 195
JNP Command ............................................................................................................................................................... 196
JOFF Command ............................................................................................................................................................. 197
JOFF,ALL Command...................................................................................................................................................... 198
JOMS Command ............................................................................................................................................................ 199
JPOS Command............................................................................................................................................................. 200
JQUERY,GUIDE Command ........................................................................................................................................... 201
JQUERY,RTKSTAT Command ...................................................................................................................................... 202
JRAIM Command ........................................................................................................................................................... 204
JRAD Command Overview ............................................................................................................................................. 205
JRAD,1 Command.......................................................................................................................................................... 206
JRAD,1,LAT,LON,HEIGHT Command ........................................................................................................................... 207
JRAD,1,P Command ...................................................................................................................................................... 208
JRAD,2 Command.......................................................................................................................................................... 209
JRAD,3 Command.......................................................................................................................................................... 210
JRAD,7 Command.......................................................................................................................................................... 211
JRAD,9,1,1 Command.................................................................................................................................................... 212
JRELAY Command......................................................................................................................................................... 213
JRESET Command ........................................................................................................................................................ 214
JRTK Command Overview ............................................................................................................................................. 215
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JRTK,1 Command .......................................................................................................................................................... 216
JRTK,1,LAT,LON,HEIGHT Command............................................................................................................................ 217
JRTK,1,P Command....................................................................................................................................................... 218
JRTK,5 Command .......................................................................................................................................................... 219
JRTK,5,Transmit Command ........................................................................................................................................... 220
JRTK,6 Command .......................................................................................................................................................... 221
JRTK,12 Command ........................................................................................................................................................ 222
JRTK,17 Command ........................................................................................................................................................ 223
JRTK,18 Command ........................................................................................................................................................ 224
JRTK,28 Command ........................................................................................................................................................ 225
JSAVE Command........................................................................................................................................................... 226
JSHOW Command ......................................................................................................................................................... 227
JSMOOTH Command..................................................................................................................................................... 229
JT Command .................................................................................................................................................................. 230
JTAU Command Overview ............................................................................................................................................. 231
JTAU,COG Command .................................................................................................................................................... 232
JTAU,SPEED Command ................................................................................................................................................ 233
JWAASPRN Command .................................................................................................................................................. 234
PCSI,0 Command (Receiver Help Query command)...................................................................................................... 235
PCSI,1 Command (Status Line A, Channel 0 command) ............................................................................................... 236
PCSI,1,1 Command (Beacon Status command)............................................................................................................. 238
PCSI,2 Command (Status Line B, Channel 1 command) ............................................................................................... 239
PCSI,3,1 Command (Receiver Search Dump command)............................................................................................... 241
PCSI,3,2 Command (Ten Closest Stations command)................................................................................................... 242
PCSI,3,3 Command (Station Database command) ........................................................................................................ 243
Messages (All)....................................................................................................................................................244
Binary Messages Code................................................................................................................................................... 244
Bin1 Message ................................................................................................................................................................. 258
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Bin2 Message ................................................................................................................................................................. 260
Bin62 Message ............................................................................................................................................................... 262
Bin65 Message ............................................................................................................................................................... 263
Bin66 Message ............................................................................................................................................................... 264
Bin69 Message ............................................................................................................................................................... 266
Bin76 Message ............................................................................................................................................................... 267
Bin80 Message ............................................................................................................................................................... 271
Bin89 Message ............................................................................................................................................................... 272
Bin93 Message ............................................................................................................................................................... 273
Bin94 Message ............................................................................................................................................................... 275
Bin95 Message ............................................................................................................................................................... 277
Bin96 Message ............................................................................................................................................................... 278
Bin97 Message ............................................................................................................................................................... 280
Bin98 Message ............................................................................................................................................................... 282
Bin99 Message ............................................................................................................................................................... 283
CRMSK Message ........................................................................................................................................................... 285
CRMSS Message ........................................................................................................................................................... 286
GLMLA Message ............................................................................................................................................................ 287
GNSSPositionData Message.......................................................................................................................................... 289
GNSSPositionRapidUpdates Message........................................................................................................................... 292
GPALM Message............................................................................................................................................................ 293
GPDTM Message ........................................................................................................................................................... 294
GPGGA Message ........................................................................................................................................................... 295
GPGLL Message ............................................................................................................................................................ 297
GPGNS Message ........................................................................................................................................................... 298
GPGRS Message ........................................................................................................................................................... 300
GPGSA Message ........................................................................................................................................................... 301
GPGST Message............................................................................................................................................................ 302
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GPGSV Message ........................................................................................................................................................... 303
GPHDG/HEHDG Message ............................................................................................................................................. 304
GPHDM/HEHDM Message............................................................................................................................................. 305
GPHDT/HEHDT Message .............................................................................................................................................. 306
GPHEV Message............................................................................................................................................................ 307
GPRMC Message........................................................................................................................................................... 308
GPROT/HEROT Message .............................................................................................................................................. 309
GPRRE Message ........................................................................................................................................................... 310
GPVTG Message............................................................................................................................................................ 311
GPZDA Message............................................................................................................................................................ 313
NMEACogSogData Message ......................................................................................................................................... 314
PASHR Message............................................................................................................................................................ 315
PSAT,GBS Message ...................................................................................................................................................... 316
PSAT,HPR Message ...................................................................................................................................................... 317
PSAT,INTLT Message.................................................................................................................................................... 318
PSAT,RTKSTAT Message ............................................................................................................................................. 319
RD1 Message ................................................................................................................................................................. 321
TSS1 Message ............................................................................................................................................................... 323
Resources.............................................................................................................................................325
Reference Documents........................................................................................................................................325
Websites.............................................................................................................................................................326
Troubleshooting ....................................................................................................................................327
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Introduction
The purpose of the GPS Technical Reference is to serve as a resource for software engineers and system integrators
engaged in the configuration of GPS receivers. It may also be of use to persons with knowledge of the installation and
operation of GPS navigation systems.
This reference covers features, commands, logs, and operating modes for a variety of Hemisphere GPS products: not all
aspects described apply to all products.
Information is provided as follows:
•
GPS Technology and Platforms provides information on the GPS engine, GPS solutions, and GPS platforms
•
Receiver Operation introduces general operational features of the receiver, receiver operation modes, and default
operation parameters
•
PocketMAX Utility provides a short introduction to PocketMAX PC and PocketMAX and what you can use them for.
For more detailed information on PocketMAX refer to the PocketMAX User Guide available from
www.hemispheregps.com.
•
Commands and Messages are grouped by their type (General, GPS, e-Dif, Data, RAIM etc.) and for each type the
commands or messages are initially listed in a table with a brief description. The commands and messages are then
described in detail each in separate topics.
•
Resources provides resources for additional information
•
Troubleshooting provides troubleshooting advice
Copyright Notice
Hemisphere GPS Precision GPS Applications
Copyright © Hemisphere GPS (2011). All rights reserved.
No part of this manual may be reproduced, transmitted, transcribed, stored in a retrieval system or translated into any language or computer
language, in any form or by any means, electronic, mechanical, magnetic, optical, chemical, manual or otherwise, without the prior written
permission of Hemisphere GPS.
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Hemisphere GPS Technical Reference v1.02
GPS Technology and Platforms
14
•
GPS Engine
•
DGPS Solutions
•
E-Dif
•
L-Dif
•
RTK
•
Post Processing
•
Hemisphere GPS Hardware Platforms
•
Evaluating Receiver Performance
GPS Technology and Platforms
GPS Engine
GPS Engine Overview
The GPS engine is always operating regardless of the DGPS mode of operation. The following sections describe the general
operation of the receiver.
•
Satellite Tracking
•
Positioning Accuracy
•
Update Rates
Both the GPS and SBAS operation of the receiver module features automatic operational algorithms. When powered for the
first time, the receiver system performs a "cold start," which involves acquiring the available GPS satellites in view and the
SBAS differential service. To do this, the receiver needs a compatible GPS antenna connected that offers a relatively clear,
unobstructed view of the sky. While you can often achieve this indoors with an antenna placed against a window, you may
need to place the antenna outside, for example on a roof or a short distance away from the building.
If SBAS is not available in a particular area, an external source of RTCM SC-104 differential correction may be used. If an
external source of correction data is needed, the external source needs to support an eight data bit, no parity and one stop bit
configuration (8-N-1). See also SBAS Overview.
Satellite Tracking
The receiver automatically searches for GPS satellites, acquires the signal, and manages the associated navigation
information required for positioning and tracking. This is a hands-free mode of operation. Satellite acquisition quality is
described as a signal-to-noise ratio (SNR) and the higher the SNR, the better the signal reception quality. SNR information is
provided by the receiver through the use of NMEA 0183 data messages available via its multiple serial ports.
Positioning Accuracy
The receiver is a sub-meter product with 95% horizontal accuracy under ideal conditions.
To determine the positioning performance of the receiver, Hemisphere GPS gathers a 24-hour data set of positions in order to
log the diurnal environmental effects and full GPS constellation changes. Data sets shorter than 24 hours tend to provide more
optimistic results.
The horizontal performance specification of 95% accuracy is, as stated above, based on ideal conditions. In reality, obstruction
of satellites, multipath signals from reflective objects, and operating with poor corrections will detract from the receiver’s ability
to provide accurate and reliable positions. Differential performance can also be compromised if the receiver module is used in
a region without sufficient ionospheric coverage. Further, if external corrections are used, the baseline separation between the
remote base station antennas can affect performance.
Since the receiver will be used in the real world, blockage of the line of sight to SBAS satellites is often inevitable. The COAST
function provides solace from obstruction of any differential correction source (SBAS, Beacon, RTCM, OmniSTAR, RTK, e-Dif)
for 30 to 40 minutes depending on the amount of tolerable performance drift. In fact, our receivers will COAST when
differential correction is lost no matter what the differential source is: SBAS, Beacon, RTCM, OmniSTAR, RTK, or e-Dif.
The estimated positioning precision is accessible through the use of NMEA 0183 command responses as described
Commands and Messages.
Because the receiver cannot determine accuracy with respect to a known location in real time (so is traditionally performed in
post-mission analyses), the precision numbers are relative in nature and are only approximates.
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Update Rates
The update rate of each NMEA 0183 and binary message of the receiver can be set independently with a maximum that is
dependant upon the message type. For example, some messages have a 1 Hz maximum while other messages have a 20 Hz
maximum. The higher update rates, such as 20 Hz, are an option and can be obtained at an additional cost.
Higher update rates are valuable for applications where:
16
•
Higher speeds are present such as in aviation
•
You have manual navigational tasks such as in agricultural guidance
•
You have an automated or autonomous navigational task such as in robotics or machine control
GPS Technology and Platforms
DGPS Solutions
COAST Technology
Crescent and Eclipse OEM boards feature Hemisphere GPS’ exclusive COAST technology that enables Hemisphere GPS
Crescent and Eclipse receivers to utilize old DGPS correction data for 40 minutes or more without significantly affecting
positioning quality.
Note: Crescent refers to Crescent, Crescent Vector, and Crescent Vector II OEM boards. Eclipse refers to Eclipse and Eclipse
II OEM boards.
When using COAST, these receivers are less likely to be affected by differential signal outages due to signal blockages, weak
signals, or interference.
Note: To obtain a full set of SBAS corrections, the receiver must receive the ionospheric map over a period of a few minutes.
After this, the receiver can "coast" until the next set of corrections has been received.
COAST technology provides the following benefits:
•
Accurate and minimal position drift during temporary loss of differential signal corrections
•
Sub-meter accuracy up to 40 minutes after differential signal loss
•
Outstanding performance in environments where maintaining a consistent differential link is difficult
•
It is standard with Crescent and Eclipse GPS receiver technology
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Hemisphere GPS Technical Reference v1.02
SBAS - Overview
The following topics describe the general operation and performance monitoring of the Space-Based Augmentation System
(SBAS) demodulator within the receiver module:
•
Automatic tracking
•
Performance
•
WAAS
•
WAAS DGPS
•
WAAS Signal Information
•
WAAS Reception
•
WAAS Coverage
SBAS Automatic Tracking
The SBAS demodulator featured within the receiver automatically scans and tracks multiple SBAS satellite signals, as
specified by the JWAASPRN command (defaulted to WAAS PRN 135 and 138, suitable for use in North America).
If the default satellites become disabled, the receiver automatically tracks different satellites. This automatic tracking enables
you to focus on other aspects of your application rather than ensuring the receiver is tracking SBAS correctly.
The SBAS demodulator features two-channel tracking that enhances the ability to maintain acquisition on an SBAS signal
satellite in regions where more than one satellite is in view.
This redundant tracking approach results in more consistent signal acquisition in areas where signal blockage of either satellite
is possible.
SBAS Performance
SBAS performance is described in terms of bit error rate (BER). The SBAS receiver requires a line of sight to the SBAS
satellite to acquire a signal.
The BER number indicates the number of unsuccessfully decoded symbols in a moving window of 2048 symbols. Due to the
use of forward error correction algorithms, one symbol is composed of two bits. The BER value for both SBAS receiver
channels is available in the RD1 message.
A lower BER indicates data is being successfully decoded with fewer errors, providing more consistent throughput. The BER
has a default no-lock of 500 or more. As the receiver begins to successfully acquire a signal, a lower BER results. For best
operation, this value should be less than 150 and ideally less than 20.
SBAS broadcasts an ionospheric map on a periodic basis and it can take up to five minutes to receive the map on startup.
Until it downloads the SBAS map the receiver uses the broadcast ionosphere model, which can result in a lower performance
compared to when the map has been downloaded. This is the case for any GPS product supporting SBAS services.
WARNING: When the map has been downloaded, you may observe a position jump due to the potential difference between
the GPS ionospheric model and the ionosphere SBAS map. To minimize the impact of this issue on the use of the receiver,
wait up to five minutes before using the receiver or issue the JQUERY,GUIDE command to 'ask' the receiver if it feels the
performance will be sufficient for operation.
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GPS Technology and Platforms
WAAS
The US Federal Aviation Administration developed the Wide Area Augmentation System (WAAS) to provide accurate
positioning to the aviation industry. In addition to providing a high quality and accurate service for this industry, the service is
available free of charge to civilians and markets in North America.
Other government agencies have developed similar WAAS-compatible systems for their respective geographic regions.
•
Europe - the European Space Agency, the European Commission and EUROCONTROL jointly developed the
European Geostationary Navigation Overlay Service (EGNOS)
•
Japan - the MTSAT Satellite-based Augmentation System (MSAS) was developed by the Japan Civil Aviation Bureau
(JCAB)
•
India - the Airport Authority of India and the Indian Space Research Organization (ISRO) are deploying the GPS
Aided Geo Augmented Navigation system (GAGAN)
These compatible augmentation systems fall into a broader category often referred to as Space Based Augmentation System
(SBAS). The receiver is capable of receiving correction data from all WAAS-compatible SBAS.
WAAS DGPS
WAAS differential, and other compatible SBAS, use a state-based approach in their software architecture. These services take
in reference data from a network of base stations and endeavor to model the sources of error directly, rather than computing
the sum impact of errors upon observed ranges. The advantage of this approach is that the error source can be more
specifically accounted for during the correction process.
Specifically, WAAS calculates separate errors for the following:
•
Ionospheric error
•
GPS satellite timing errors
•
GPS satellite orbit errors
Provided that a GPS satellite is available to the WAAS reference station network for tracking purposes, orbit and timing error
corrections will be available for that satellite. Ionospheric corrections for that satellite are only available if the signal passes
through the ionospheric map provided by WAAS, which covers most of North America.
To improve the ionospheric map provided by WAAS, the receiver extrapolates information from the broadcast ionospheric
coverage map, extending its effective coverage. This allows the receiver to be used successfully in regions that competitive
products may not. This is especially important in Canada for regions north of approximately 54° N latitude and for outer
regions of the Caribbean.
The process of estimating ionospheric corrections beyond the WAAS broadcast map is not as good as having an extended
WAAS map and accuracy degradation may occur.
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The map links below depict the broadcast WAAS ionospheric map coverage and the Hemisphere GPS extrapolated version,
respectively. As the two maps show, the Hemisphere GPS extrapolated version’s coverage is greater in all directions,
enhancing usable coverage.
20
•
Broadcast WAAS ionospheric correction map
•
Extrapolated WAAS ionospheric correction map
GPS Technology and Platforms
WAAS Signal Information
WAAS and other SBAS systems transmit correction data on the same frequency as GPS, allowing the use of the same
receiver equipment used for GPS. Another advantage of having WAAS transmit on the same frequency as GPS is that only
one antenna element is required.
WAAS Reception
Since WAAS broadcasts on the same frequency as GPS, the signal requires a line of site in the same manner as GPS to
maintain signal acquisition.
Because of their locations, SBAS satellites may appear lower on the horizon than GPS satellites—it depends on the
geographic position on land. When using WAAS correction data, the receiver can provide the azimuth and elevation of all
satellites to aid in determining their position with respect to the antenna.
WAAS Coverage
The figure below depicts the current WAAS coverage provided by the geostationary satellites.
The WAAS satellites are identified by their pseudorange number (PRN). In some areas, two or more satellites may be visible.
Note: Signal coverage may be present in some areas without either sufficient ionospheric map coverage or satellites with valid
orbit and clock corrections. In such cases performance may be degraded compared to areas fully covered by the WAAS
ionospheric coverage.
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EGNOS
The European Geostationary Navigation Overlay Service (EGNOS) uses multiple geostationary satellites and a network of
ground stations to transmit differential correction data for public use. EGNOS is currently located over the Atlantic Ocean and
Africa.
Because of their location over the equator, these satellites may appear lower over the horizon as compared to GPS satellites it depends on the geographic position on the land. In regions where the satellites appear lower on the horizon, they may be
more susceptible to being masked by terrain, foliage, buildings or other objects, resulting in signal loss. Increased distance
from the equator and the satellite's longitude cause the satellite to appear lower on the horizon. Hemisphere GPS's COAST
technology helps alleviate this problem by maintaining system performance when EGNOS signal loss occurs for extended
periods of time. More information on COAST technology is provided later in this chapter.
The figure below shows approximate EGNOS coverage provided by the satellites. Virtually all of Europe, part of Northern
Africa, and part of the Middle East is covered with at least one signal. Most of Europe is covered by three signals.
Note: Increased distance from the equator and the satellite’s longitude cause the satellite to appear lower on the horizon.
Although a good amount of signal coverage is shown in northern latitudes for EGNOS, it may not be usable because of its low
elevation angle and the potential for it to be obstructed. Testing of the system in the area of its use is recommended to ensure
that the signal is sufficiently available.
MSAS
The MTSAT Satellite-based Augmentation System (MSAS) is currently run by the Japan Meteorological Agency (JMA). MSAS
provides GPS augmentation information to aircraft through MTSAT (Multi-functional Transport Satellite) located approximately
36000 km above the equator (geostationary earth orbit).
MSAS generates GPS augmentation information by analyzing signals from GPS satellites received by monitor stations on the
ground. This augmentation information consists of GPS-like ranging signal and correction information on GPS errors caused
by the satellites themselves or by the ionosphere.
The MSAS signal provides accurate, stable, and reliable GPS position solutions to aircraft, resulting in a considerable
improvement in the safety and reliability of GPS positioning. This enables aviation users who are under very strict safety
regulations to use GPS positioning as a primary navigation system.
Visit http://www.jma.go.jp/jma/jma-eng/satellite/ for more information on MSAS and MTSAT.
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GPS Technology and Platforms
GAGAN
The GPS Aided Geo Augmented Navigation system (GAGAN) is currently under deployment by the Indian government and is
anticipated to be operational by 2011. It operates similarly to the other SBAS regions described previously and will broadcast
on one geostationary satellite (PRN 127) over the Western portion of the Indian Ocean. GAGAN should be visible in India at
elevation angles in excess of 50º above the horizon. This will provide an excellent correction source in virtually all areas of the
subcontinent.
Radiobeacon
Radiobeacon Overview
Many marine authorities, such as Coast Guards, have installed networks of radiobeacons that broadcast DGPS corrections to
their users. With increasing use of these networks for terrestrial applications, there is increasing densification of these
networks inland.
Radiobeacon Range
The broadcasting range of a 300 kHz beacon depends on a number of factors, including:
•
Transmission power
•
Free space loss
•
Ionospheric state
•
Surface conductivity
•
Ambient noise
•
Atmospheric losses
Signal strength decreases with distance from the transmitting station, mostly due to spreading loss. This loss is a result of the
signal’s power being distributed over an increasing surface area as the signal radiates away from the transmitting antenna.
The expected broadcast range also depends on the conductivity of the surface over which it travels. A signal will propagate
further over a surface area with high conductivity than over a surface with low conductivity. Lower conductivity surfaces, such
as dry, infertile soil, absorb the power of the transmission more than higher conductivity surfaces, such as sea water or arable
land.
A radiobeacon transmission has three components:
1.
Direct line-of-sight wave
The line-of-sight wave is insignificant beyond visual range of the transmitting tower and does not have a substantial
impact upon signal reception.
2.
Ground wave
The ground wave portion of the signal propagates along the surface of the earth, losing strength due to spreading
loss, atmospheric refraction and diffraction, and attenuation by the surface over which it travels (dependent upon
conductivity).
3.
Sky wave
Depending on its reflectance, this skyward portion of the beacon signal may bounce off the ionosphere and back to
Earth, causing reception of the ground wave to fade. Fading—which may cause reception to fade in and out—occurs
when the ground and sky waves interfere with each other. This problem usually occurs in the evening when the
ionosphere becomes more reflective and usually on the edge of coverage areas. Fading is not usually an issue with
overlapping coverage areas of beacons and their large overall range.
Atmospheric attenuation plays a minor part in signal transmission range because it absorbs and scatters the signal. This type
of loss is the least significant of those described.
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Hemisphere GPS Technical Reference v1.02
Radiobeacon Reception
Various noise sources affect beacon reception and include:
•
Engine noise
•
Alternator noise
•
Noise from power lines
•
DC to AC inverting equipment
•
Electric devices such as CRTs, electric motors, and solenoids
Noise generated by these types of equipment can mask the beacon signal, reducing or impairing reception.
Radiobeacon Antenna Location
When using the internal beacon receiver as the correction source, antenna location will influence the performance of the
internal beacon receiver.
A good location will:
•
Have a clear view of the sky (important for GPS, WAAS, and OmniSTAR signal reception)
•
Be at least three feet away from all forms of transmitting antennas, communications, and electrical equipment, to
reduce the amount of noise present at the antenna
•
Be the best for the application, such as the center line of the vehicle or vessel (the position calculated by the beacon
receiver is measured to the center of the antenna)
•
Not be in areas that exceed specified environmental conditions
Radiobeacon Coverage
The figure below shows the approximate radiobeacon coverage throughout the world. Light shaded regions denote current
coverage, with beacon stations shown as white circles. The world beacon networks continue to expand. For more current
coverage, visit the Hemisphere GPS web site at www.hemispheregps.com.
24
GPS Technology and Platforms
OmniSTAR
OmniSTAR Overview
OmniSTAR is a worldwide terrestrial DGPS service that provides correction data to subscribers of the system with the use of a
geostationary transponder.
The information broadcast by OmniSTAR DGPS is based on a network of reference stations— placed at geographically
strategic locations—that communicate GPS correction data to control centers. At the control centers the GPS correction data
is decoded, checked, and repackaged into a proprietary format for transmission to a geostationary L-band communications
satellite. The satellite rebroadcasts the correction information back to earth over a large signal footprint where the Hemisphere
GPS L-band differential satellite receiver demodulates the data.
The OmniSTAR signal content is not RTCM SC-104, but a proprietary wide-area signal that’s geographically independent.
With this service, the positioning accuracy does not degrade as a function of distance to a base station because the data
content is not composed of a single base station’s information; it is composed of an entire network’s information. When the
Hemisphere GPS L-band DGPS receiver demodulates the proprietary signal it converts it into a local-area format for input to
the GPS receiver (standard RTCM SC-104, message Type 1).
The L-band DGPS receiver interpolates corrections from the wide-area signal, specific to the location using Virtual Base
Station (VBS) processing algorithms. The resulting RTCM corrections are those that would be calculated if a reference station
were set up at the present location. This type of solution ensures a consistent level of accuracy across the entire coverage
area. The GPS receiver provides position information to the L-band DGPS receiver for VBS calculations.
OmniSTAR offers three levels of service: VBS (described above), HP, and XP. HP and XP require a dual frequency receiver
such as the Eclipse to function properly and are approximately three to seven times more accurate than the VBS service.
OmniSTAR Signal Information
The OmniSTAR L-band signal is a line-of-sight UHF signal that is similar to GPS. For the L-band differential receiver to acquire
the signal, there must be a line of sight between the antenna and the geostationary communications satellite.
Various L-band communications satellites are used for transmitting the correction data to OmniSTAR users around the world.
When the L-band receiver has acquired an OmniSTAR signal, the elevation and azimuth are available in the menu system to
enable troubleshooting line-of sight problems.
Contact OmniSTAR for further information on this service.
OmniSTAR Reception
The OmniSTAR service broadcasts at a similar frequency to GPS and as a result is a line-of-sight system; there must be a line
of sight between the antenna and the OmniSTAR satellite for reception of the service.
The OmniSTAR service uses geostationary satellites for communication. The elevation angle to these satellites is dependent
upon latitude. For latitudes higher than approximately 55° North or South, the OmniSTAR signal may be blocked more easily
by obstructions such as trees, buildings, and terrain.
OmniSTAR Coverage
The figure below shows approximate OmniSTAR service coverage. Regions without coverage, or with poor coverage, are
shown with dark shading (Alaska, Northern Canada, Greenland, Iceland, and Northern Russia).
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Hemisphere GPS Technical Reference v1.02
Note: Signal coverage may be present in some areas without reference stations within the region. Operating outside the
reference station network may cause the applicability of the correction data to be less, resulting in a lower degree of
positioning accuracy due to spatial decorrelation.
OmniSTAR Automatic Tracking
The Hemisphere GPS L-band DGPS receiver features an automatic mode that allows it to locate the best spot beam if more
than one is available in a particular region. With this function you do not need to adjust the receiver’s frequency. The receiver
also features a manual tune mode for flexibility.
See the JFREQ command for more information on automatic and manual tuning.
OmniSTAR Receiver Performance
The OmniSTAR receiver provides both a lock indicator and a BER (Bit Error Rate) to describe the lock status and reception
quality. Both these features depend on a line of sight between the antenna and the geostationary communications satellite
broadcasting the OmniSTAR correction information.
OmniSTAR-capable Hemisphere GPS antennas is designed with sufficient gain at low elevation angles to perform well at
higher latitudes where the signal power is lower and the satellite appears lower on the horizon. The BER number indicates the
number of unsuccessfully decoded symbols in a moving window of 2048 symbols. Because of the use of forward error
correction algorithms, one symbol is composed of two bits.
The BER has a default, no-lock value of 500. As the receiver begins to successfully acquire the signal a lower BER results.
For best operation this value should be less than 150 and ideally less than 20.
OmniSTAR Subscription and Contact Information
OmniSTAR Service Activation
You can activate OmniSTAR DGPS service for a DGPS MAX receiver by contacting the service provider in the your region.
Contact OmniSTAR with the unit number and OmniSTAR will activate the subscription over the air. Be prepared to have the
receiver ready to receive the OmniSTAR signal for subscription validation.
26
GPS Technology and Platforms
OmniSTAR License Agreement
OmniSTAR requires that the enclosed license agreement be filled out the before subscription activation. Please read the
agreement thoroughly before filling in the require information. Be ready to fax the completed agreement when contacting
OmniSTAR.
Contacting OmniSTAR
Contact the office responsible for subscriptions in the your area based on the OmniSTAR coverage map below.
Visit www.omnistar.com for the most current contact information.
Location
Telephone Number
Website
North America
South America
1-888-883-8476
www.omnistar.com
Europe
Northern Africa
Middle East
West Asia
31-70-317-0900
www.omnistar.nl
Australia
Far East
61-8-9322 5295
http://omnistar.com.au
Southern Africa
27 21 527 8950
www.omnistar.co.za
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Hemisphere GPS Technical Reference v1.02
Crescent Base Station Operation
Crescent Base Station Overview
The Crescent receiver with e-Dif subscription can operate in a DGPS base station mode. NMEA 0183 commands need to be
sent to the receiver to enter this mode. These commands may be automatically issued through customized software or
through a simple terminal interface running on a PC, PDA, or data logger. DGPS Base Station Commands provides detailed
information on the commands supported by the base station application.
Crescent Base Station Startup
When the receiver running the e-Dif application first starts up, it requires a few minutes to gather enough satellite tracking
information to model the errors for the future. Once commands are sent to put the receiver into base station mode, corrections
will be generated and can be sent via the serial port to rover receivers. In some more challenging GPS environments, the time
required to model errors can take up to 10 minutes. The receiver must be stationary during this process and the antenna for
the base station must be secured in a stable location.
Crescent Base Station Calibration
Base station calibration is the process of modeling the errors at the base station. Calibration can be performed in either a
relative or an absolute sense, depending on positioning needs. Relative positioning provides positions that are accurate to one
another but there may be some offset from the true geographical position.
Calibrating for relative positioning is easier than for absolute position since you are not restricted to using a point with known
coordinates. Calibrating for absolute positioning mode requires placing the GPS antenna at a known reference location. Care
should be taken to use a location that has good sky visibility and is relatively free from obstructions.
Crescent Base Station Performance
Base station performance depends primarily on the site location for the base station GPS antenna. An ideal location would
have no obstructions above the height of the antenna, offering a full 180º by 360º view of the sky. In reality, obstructions such
as trees, vehicles, people, and buildings nearby both block satellite signals and reflect interfering signals called multipath
signals. Multipath degrades the accuracy of the satellite measurements and detracts from the receiver’s ability to provide
accurate and reliable corrections for the rovers.
For a rover to work optimally, a base station should be near by the rover’s area of operation. As distance from the base to the
rover increases, the modeling process cannot tune the solution to the exact environmental conditions at the rover’s location
and the rover’s accuracy will not be as good. Best performance is attained when the distance from your base to your rover is
less than 50 km (30 miles). Generally, there is little to no advantage to using a base station if it is more than 300 km (180
miles) from the rover.
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GPS Technology and Platforms
e-Dif - Extended Differential Option for the Crescent Receiver
The Crescent receiver module is designed to work with Hemisphere GPS’ patented Extended Differential (e-Dif) software. eDif is an optional mode where the receiver can perform with differential-like accuracy for extended periods of time without the
use of a differential service. It models the effects of ionosphere, troposphere, and timing errors for extended periods by
computing its own set of pseudo-corrections.
e-Dif may be used anywhere geographically and is especially useful where SBAS networks have not yet been installed, such
as South America, Africa, Australia, and Asia. Two things are required to enable e-Dif. First your receiver will require the e-Dif
application software to be installed on it. As well, a software key, called a subscription code, is needed for the receiver to use
e-Dif. Both can be installed in the field using a PC computer. See Using RightARM to Load Firmware if you need to install the
application firmware onto your receiver. To install a subscription code, contact Hemisphere GPS for a JK command which can
be issued to your receiver.
Positioning with e-Dif is jump-free compared to a receiver working with just raw GPS provided the receiver consistently
maintains a lock on at least four satellites at one time. The accuracy of positioning will have a slow drift that limits use of the eDif for approximately 30 to 40 minutes although it depends on how tolerant the application is to drift as e-Dif can be used for
longer periods.
This mode of operation should be tested to determine if it is suitable for the application and for how long the user is
comfortable with its use. As accuracy will slowly drift, the point at which to recalibrate e-Dif to maintain a certain level of
accuracy must be determined.
The figure below displays the static positioning error of e-Dif while it is allowed to age for fourteen consecutive cycles of 30
minutes. The top line indicates the age of the differential corrections. The receiver computes a new set of corrections using eDif during the calibration at the beginning of each hour and modifies these corrections according to its models. After the
initialization, the age correspondingly increases from zero until the next calibration.
The position excursion from the true position (the lines centered on the zero axis are northing [dark line] and easting [light
line]) with increasing correction age is smooth from position to position; however, there is a slow drift to the position. The
amount of drift depends on the rate of change of the environmental errors relative to the models used inside the e-Dif software
engine.
Note: You decide how long e-Dif is to function before between calibrations and you should test this operation mode to
determine an acceptable level of performance.
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Hemisphere GPS Technical Reference v1.02
e-Dif Rover Mode Operation
Rover mode operation of the Crescent receiver unit with the optional e-Dif application requires NMEA 0183 commands. These
commands may be automatically issued through customized software or through a simple terminal interface running on a PC,
PDA or data logger. See e-Dif Commands for detailed information on the commands supported by the e-Dif feature.
e-Dif Startup
On startup, the receiver with the e-Dif application software running requires a few minutes to gather enough satellite tracking
information to model the errors for the future. And in some environments this can take up to 10 minutes. The receiver does not
have to be stationary for this process but it must be tracking the satellites throughout it. This process of gathering information
and the subsequent initialization of e-Dif is referred to as "calibration."
e-Dif Rover Calibration
Rover calibration is the process of modeling the errors at the rover. Calibration can be performed in either a relative or an
absolute sense, depending on positioning needs. Relative positioning provides positions that are accurate to one another but
there may be some offset from the true geographical position. Additionally, unless the same point is used for all calibrations
and its assumed position stored, it is possible for different cycles of e-Dif to have an offset.
Calibrating for relative positioning is easier than for absolute position, since you are not restricted to using a point with known
coordinates. Calibrating for absolute positioning mode requires placing the GPS antenna at a known reference location. Use
this point for subsequent calibrations.
e-Dif Rover Performance
The Crescent receiver’s positioning performance is dependant upon the rate at which the environmental modeling of e-Dif and
the environmental errors diverge. The more that e-Dif is able to model the errors correctly, the longer it will provide reliable and
accurate positioning. As there is no way in real time to know the rate of divergence, a rule of thumb is to set the maximum age
of differential to either 30 or 40 minutes, depending on how much error the application is able to tolerate (or simply recalibrate
before 30 to 40 minutes goes by). Hemisphere GPS testing has shown that relative accuracy will often be better than 1.0 m
95% of the time after 30 minutes of e-Dif operation.
You should perform testing at your location to determine the level of performance that would be seen on average. When
testing this feature, it is a good idea to look at a number of e-Dif cycles per day, and monitor performance against a known
coordinate and possibly other receivers in autonomous and differential mode. You should do this over a number of days with
different states of the ionosphere.
You can monitor the energy level of the ionosphere based upon the amount of solar flare activity at
http://www.spaceweather.com.
30
GPS Technology and Platforms
L-Dif - Local Differential Option
Local differential (L-Dif) is a specialized message type that can be sent only between two Crescent-based receivers. One
receiver is used as the base station and must remain stationary. It is extremely useful to know the coordinates of the base
station position but averaging the position over several days will also suffice. The second receiver is used as a rover and the
messages must be sent either through a cable or over a radio link.
L-Dif Startup
On startup, the receiver with the L-Dif running requires several commands to initialize the proprietary messages that are sent
over the air.
L-Dif Performance
The receiver’s positioning performance in L-Dif mode is dependant upon:
•
Environment of the base and rover receivers
•
Distance between them and
•
Accuracy of the entered coordinates of the base station
Hemisphere GPS suggests you perform your own testing at your location to determine the level of performance you would
expect on average. When testing this feature, conduct tests of 12-24 hours—in different environments—and monitor
performance against a known coordinate. Do this over a number of days with different states of the ionosphere.
You can monitor the energy level of the ionosphere based upon the amount of solar flare activity at
http://www.spaceweather.com.
RTK Overview
Real Time Kinematic (RTK) positioning is the highest form of navigational accuracy for GPS receivers. Hemisphere GPS offers
RTK for both Crescent and Eclipse platforms. See RTK commands for more information.
Post Processing
Crescent and Eclipse receiver modules can output raw measurement data for post processing applications. The raw
measurement and ephemeris data are contained in the Bin 94 and Bin 95 messages, and Bin 96 (Crescent) or Bin 76
(Eclipse) messages. All three messages must be logged in a binary file. Crescent receivers must log Bin 94, 95, and 96
messages, while Eclipse receivers must log Bin 94, 95, and 76 messages. Depending on the application, the binary data can
be logged to a file and then translated to RINEX at a later time on a PC.
Hemisphere GPS provides a RINEX translator. It is available by contacting technical support at Hemisphere GPS; however,
because there is limited ability to store station information in the binary file, developers may consider writing their own
translator. Some code is available for developers but with very limited support. The code should be self-evident to developers
familiar with RINEX and knowledgeable in C language.
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Hemisphere GPS Technical Reference v1.02
Hemisphere GPS Hardware Platforms
Crescent Vector OEM Development Kit
Crescent Vector OEM Development Kit Overview
The purpose of the Crescent Vector OEM Development Kit is to provide accurate position and reliable heading information at
high update rates. To accomplish this, the unit uses one high performance GPS engine and two multipath resistant antennas
for GPS signal processing. One antenna is designated the primary GPS antenna and the other the secondary GPS antenna.
The unit computes the position by referencing the primary antenna center. It computes the heading by referencing the Vector
baseline (formed by the distance between the primary and secondary antennas' centers).
Crescent Vector Calculations
The Crescent Vector's GPS engine uses both the L1 GPS C/A code and phase data to compute the location of the secondary
GPS antenna in relation to the primary GPS antenna with a very high sub-centimeter level of precision. The technique of
computing the location of the secondary GPS antenna with respect to the primary antenna, when the primary antenna is
moving, is very similar to how "real time kinematic", or "RTK" solutions are computed. The primary antenna for the Crescent
Vector operates in much the same way as the base antenna does for RTK
RTK technology is very sophisticated and requires a significant number of possible solutions to be analyzed where various
combinations of integer numbers of L1 wavelengths to each satellite intersect within a certain search volume. The integer
number of wavelengths is often referred to as the “ambiguity,” as they are ambiguous at the start of the RTK solution.
The Crescent Vector places a constraint on the RTK solution with the prior knowledge that the secondary GPS antenna has a
fixed separation usually of 0.50 m (1.6 ft)—this can vary based on setup—from the primary GPS antenna. This considerably
reduces the search volume, and therefore the startup times, because the location of the secondary antenna can theoretically
fall only on the surface of a sphere with a radius of 0.50 m (1.6 ft) centered on the location of the primary antenna, versus a
normal search volume that is greater than a cubic meter.
Supplemental Sensors
Supplemental Sensors - Reduced Time Search
In addition to incorporating the GPS engine, integrated inside the Crescent Vector are a gyro and a tilt sensor. When used, the
tilt sensor aids the rate at which a heading solution is computed on startup and during reacquisition if the GPS heading is lost
due to obstructions. Each supplemental sensor may be turned on or off individually; however, the full functionality of the
Crescent Vector is realized only when all are used.
The tilt sensor further reduces the search volume from the volume associated with just a fixed antenna separation, because
the Crescent Vector knows the approximate inclination of the secondary antenna with respect to the primary. The gyro only
benefits reacquisition, because it initially requires a GPS heading to self-calibrate. The gyro further reduces the search
volume.
Reducing the RTK search volume also has the benefit of improving the reliability and accuracy of selecting the correct heading
solution by eliminating other possible erroneous solutions.
Note: Tilt and gyro aiding may be turned on depending on the product and may be disabled through user commands. Refer to
your product's documentation for more information.
Supplemental Sensors - Heading System Backup
The Crescent Vector uses the gyro as a secondary source of heading for up to three minutes when there is a GPS outage due
to obstruction. If the outage lasts more than three minutes, the gyro will be deemed to have drifted too far and will stop
outputting. There is no user control over the timeout period of the gyro.
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GPS Technology and Platforms
Evaluating Receiver Performance
Hemisphere GPS evaluates performance of the receiver with the objective of determining best-case performance in a realworld environment. Our testing has shown that the receiver achieves a performance better than 0.6 m 95% of the time in
typical DGPS modes.
The qualifier of 95% is a statistical probability. Manufacturers often use a probability of RMS, one sigma, or one standard
deviation. These three terms all mean the same thing and represent approximately 67% probability. Performance measures
with these probabilities are not directly comparable to a 95% measure since they are lower probability (less than 70%
probability).
Table 1 summarizes the common horizontal statistical probabilities.
Table 1: Horizontal Accuracy Probability Statistics
Accuracy Measure
Probability (%)
rms (root mean square)
63 to 68
CEP (circular error probability)
50
R95 (95% radius)
95 to 98
2drms (twice the distance root)
95
It is possible to convert from one statistic to another using Table 2. Using the value where the 'From' row meets the 'To'
column, multiply the accuracy by this conversion value.
Table 2: Accuracy Conversions
To
CEP
rms
R95
2drms
CEP
1
1.2
2.1
2.4
rms
0.83
1
1.7
2.0
R95
0.48
.59
1
1.2
2drms
0.42
.5
.83
1
From
For example, Product A, after testing, has an accuracy of 90 cm 95% of the time (R95).
To compare this to Product B that has a sub-meter horizontal rms specification of 60 cm:
1.
Select the value from where the 'R95' row and the 'rms' column intersect (to convert to rms). This conversion value is
0.59.
2.
Multiply the 90 cm accuracy by this conversion factor and the result is 53 cm rms. Compared to Product B’s 60 cm
specification of sub-meter rms, Product A offers better performance.
To properly evaluate one receiver against another statistically, the receivers should be using identical correction input (from an
external source) and share the same antenna using a power splitter (equipped with appropriate DC-blocking of the receivers
and a bias-T to externally power the antenna). With this setup, the errors in the system are identical with the exception of
receiver noise.
Although this is a comparison of the GPS performance qualities of a receiver, it excludes other performance merits of a GPS
engine. The dynamic ability of a receiver should always be compared in a similar way with the test subjects sharing the same
antenna. Unless a receiver is moving, its software filters are not stressed in a similar manner to the final product application.
When testing dynamically, a much more accurate reference would need to be used, such as an RTK system, so that a "truth"
position per epoch is available.
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Hemisphere GPS Technical Reference v1.02
Further, there are other performance merits of a GPS engine such as its ability to maintain a lock on GPS and SBAS satellites.
When evaluating this ability, the same GPS antenna should be shared between the receivers test subjects. For the sake of
comparing the tracking availability of one receiver to another, no accurate "truth" system is required unless performance
testing is also to be analyzed. Again, an RTK system would be required; however, it is questionable how its performance will
fare with environments where there are numerous obstructions such as foliage. Other methods of providing a truth reference
may need to be provided through observation times on surveyed monuments or traversing well-known routes.
Should you look to compare two RTK systems, determining truth can be very complicated. A rigorous dynamic comparison of
two competing RTK systems should only be attempted by individuals and organizations familiar with RTK and potentially with
inertial navigation equipment. Fortunately, most manufacturer's RTK performance is specified in similar accuracy values, and
in general, RTK accuracy is quite similar across different manufacturers.
Note: Contact Hemisphere GPS technical support for further assistance in developing a test setup or procedure for evaluation
of the receiver.
34
Receiver Operation
Receiver Operation Overview
When turned on, the receiver goes through an internal startup sequence. It is, however, ready to communicate immediately.
Refer to the receiver-specific manual for the power specifications of the product.
When its antenna has an unobstructed view of the sky, the receiver provides a position in approximately 60 seconds and
acquires SBAS lock in about 30 seconds more.
Note: The receiver can take up to 5 minutes to receive a full SBAS ionospheric map. Optimum accuracy is obtained when the
receiver is processing corrected positions using complete ionosphere information.
Communicating with the Receiver
Communicating with Receivers
The receiver module features three primary serial ports (A, B, C) that may be configured independently of each other.
The ports can be configured to output a combination of data types:
•
NMEA 0183
•
Hemisphere GPS proprietary binary format
•
RTCM SC-104
The usual data output is NMEA 0183 messages because these are the industry standard.
Note: If different data types are required to be output from the receiver simultaneously, such as NMEA 0183 and binary or
NMEA 0183 and RTCM SC-104, ensure that the software used for logging and processing of the data has been designed to
correctly parse the different data types from the single stream of data.
NMEA 0183 Messages
NMEA 0183 is a communications standard established by the National Marine Electronics Association (NMEA). NMEA 0183
provides data definitions for a variety of navigation instruments and related equipment such as gyrocompasses, Loran
receivers, echo sounders, and GPS receivers.
NMEA 0183 functionality is virtually standard on all GPS equipment available. NMEA 0183 has an ASCII character format that
enables the user to read the data via a receiving device with terminal software.
The following is an example of one second of NMEA 0813 data from the receiver:
$GPGGA,144049.0,5100.1325,N,11402.2729,W,1,07,1.0,1027.4,M,0,M,,010 *61
$GPVTG,308.88,T,308.88,M,0,0.04,N,0.08,K*42
$GPGSV,3,1,10,02,73,087,54,04,00,172,39,07,66,202,54,08,23,147,48,*79
$GPGSV,3,2,10,09,23,308,54,11,26,055,54,15,00,017,45,21,02,353,45*78
$GPGSV,3,3,10,26,29,257,51,27,10,147,45,45,,,,,,,,*74
The NMEA 0183 standard allows manufacturers to define proprietary custom commands and to combine data into proprietary
custom messages. Proprietary NMEA 0813 messages are likely to be supported only by specific manufacturers.
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Hemisphere GPS Technical Reference v1.02
All messages and ports can be configured independently (see example below).
Port
Baud
Rate
Messages
A
9600
GPGGA, one every 1 second
GPGSV, one every 5 seconds
B
19200
GPGGA, one every 2 seconds
Bin1, one every 1 second
Bin2, one every 1 second
A selection of NMEA 0183 data messages can be configured at various update rates with each message having a maximum
update rate. A different selection of NMEA 0183 messages with different rates can be configured on another port.
Commands and Messages Overview presents information about the NMEA 0183 interface of the receiver smart antenna.
See Reference Documents for contact information if you need to purchase a copy of the NMEA 0183 standard.
Hemisphere GPS Proprietary Binary Interface
Hemisphere GPS proprietary binary messages may be output from the receiver simultaneously with NMEA 0183 messages.
Binary messages are inherently more efficient than NMEA 0183 and would be used when maximum communication efficiency
is required. Some receiver-specific pieces of information are only available through binary messages, such as raw data for
post processing.
Note: If you need to log binary data, make sure the logging software has opened the file as a binary file; otherwise, data may
be lost.
36
Receiver Operation
RTCM SC-104 Protocol
RTCM SC-104 is a standard that defines the data structure for differential correction information for a variety of differential
correction applications. It was developed by the Radio Technical Commission for Maritime services (RTCM) and has become
an industry standard for communication of correction information. RTCM is a binary data protocol and is not readable with a
terminal program. Because it is a binary format and not ASCII text, it appears as "garbage" data on screen.
The following is an example of how the RTCM data appears on screen:
mRMP@PJfeUtNsmMFM{nVtIOTDbA^xGh~kDH`_FdW_yqLRryrDuh
cB\@}N`ozbSD@O^}nrGqkeTlpLLrYpDqAsrLRrQN{zW|uW@H`z]~aG
xWYt@I`_FxW_qqLRryrDCikA\@Cj]DE]|E@w_mlroMNjkKOsmMFM{
WDwW@HVEbA^xGhLJQH`_F`W_aNsmMFM[WVLA\@S}amz@ilIuP
qx~IZhTCpLLrYpdP@kOsmMFM[kVDHwVGbA^P{WWuNt_SW_yMs
mMnqdrhcC\@sE^ZfC@}vJmNGAHJVhTCqLRryrdviStW@H_GbA^
P{wxu[k
All Hemisphere GPS receivers support RTCM v2.x Type 1, Type 5, Type 6, and Type 9 messages for DGPS positioning.
Hemisphere GPS receivers do not support RTCM v2.x messages for RTK positioning. However RTCM v3.x messages (Type
1001 through 1008) are suitable for RTK positioning.
Note: RTCM v2.x is a local area data standard. This means that performance degrades as a function of
distance from the base station when:
•
Positioning with external connection input to the receiver from an external source or
•
Outputting corrections from the receiver to another GPS receiver.
The additional degradation depends on the difference in observed orbit and ionospheric errors between
the reference station and the remote unit. A general rule of thumb is an additional 1 m error per 100
miles.
This error is often seen as a bias in positioning, resulting in a position offset. The scatter of the receiver
is likely to remain close to constant.
See Reference Documents for RTCM contact information to purchase a copy of the RTCM SC-104 specifications.
37
Hemisphere GPS Technical Reference v1.02
Firmware and Subscription Codes
Firmware
About Firmware
Hemisphere GPS products are built on one of three receiver platforms, each of which has specific firmware applications
available.
•
Crescent - WAAS, e-Dif, OmniSTAR VBS, L-Dif/RTK base, L-Dif/RTK rover
•
Crescent Vector - WAAS, RTK rover
•
Eclipse - WAAS/RTK base, RTK rover, OmniSTAR HP/XP
Some products may require purchasing a subscription code to unlock specific functionality. See Subscription Codes for more
information.
As its name suggests, firmware is somewhere between hardware and software. Like software, it is a computer program which
is executed by a microprocessor or a microcontroller. But it is also tightly linked to a piece of hardware, and has little meaning
outside of it.
Within the context of GPS, the hardware is the GPS receiver and it is the receiver’s processor that executes the firmware. The
receiver’s processor supports two simultaneous versions of firmware but only one version operates at a given time. The two
versions—referred to as applications—may have different functionality. Use the JAPP command to change between two
receiver applications.
Using RightARM to Load Firmware
RightARM is Hemisphere GPS software that allows you to load the various GPS receiver firmware options and updates as
they are provided by Hemisphere GPS.
To load the firmware:
38
1.
Download the latest version of RightARM from http://www.hemispheregps.com.
2.
Install RightARM application on your computer.
3.
Connect the receiver to your computer and power on the receiver.
Receiver Operation
4.
Double-click the RightARM icon
to launch the program. The following screen appears.
5.
Click the Open Receiver button
can identify a connected receiver.
6.
Select the Comm Port on your computer to which the receiver is connected, select the 19200 baud rate for the
receiver, and then click OK.
or select Receiver > Connect. The Open Receiver window appears, so you
Note: You must set the baud rate to 19200.
When RightARM has successfully connected to the receiver the following message appears in the lower left corner of
the screen.
39
Hemisphere GPS Technical Reference v1.02
. The Programming View window appears, enabling you to select
7.
Click the Programming View button
different firmware programming options.
8.
Select the Program Type you want to install and then click Select File. The Open window appears.
Note: Most Hemisphere GPS receivers have two application locations available for firmware. In this case, select the
Application option under Program Type and follow the remaining steps. Once the process is complete, you will repeat
the process, selecting the Application 2 option when you reach this step again.
9.
Select the required firmware file from the location where you saved it on your computer and click Open. "File Loaded"
appears in the status window on the Programming View window.
10. Click the Erase and Program button to erase the firmware that is currently installed on the receiver in the selected
application location and install the newly selected file in its place. "Erasing...Please Wait" appears in the Status field
and a progress bar below this message indicates the programming progress. Once the new firmware has been
successfully loaded on the receiver "Programming Done" appears in the Status field.
Note: Before pressing the Erase and Program button, the Activate Loader check box in the Programming View
window will be selected. After pressing the Erase and Program button, the check box should be cleared and the
Status field should show that the receiver is in loader mode and ready to receive the new firmware file. If the Activate
Loader check box remains selected, turn the receiver off and then back on again, close and restart RightARM, and
then start over at step 5.
WARNING: Do not to interrupt the power supply to the receiver, and do not interrupt the communication link between
the PC and the receiver until programming is complete. Failure to do so may cause the receiver to become
inoperable and will require it to be returned to the factory for repair.
40
Receiver Operation
11. Once the appropriate firmware has been loaded, click the Close button to close the Programming View window.
Note: If a second application needs to be loaded, turn off the receiver, repeating all the steps starting at step 4, and
on step 8 select the Application 2 option from the Program Type field.
12. Exit RightARM, turn off your receiver, and then disconnect the receiver from your computer.
41
Hemisphere GPS Technical Reference v1.02
Subscription Codes
Subscription Codes
Receiver activation has two steps:
1.
Load application firmware
2.
Enter the subscription code
This section covers:
•
Finding the serial number and inputting a subscription code (e-Dif, L-Dif [base and rover], RTK, 20 Hz or 10Hz, etc.)
into a Hemisphere GPS receiver
•
Viewing the status and interpreting the $JI subscription date codes
•
The difference between the receiver’s response to the $JK and $JI commands
Subscribing to an Application
Activating an application code on a Hemisphere GPS receiver requires the following:
•
Serial communication cable to connect the Hemisphere GPS receiver to the serial COM port on the computer
•
Download SLXMon from the www.hemispheregps.com and install on the computer or use a generic terminal program
such as HyperTerminal
•
Load the application to which to subscribe onto the Hemisphere GPS receiver (see Using RightARM to Load
Firmware)
•
Purchase the application subscription code from Hemisphere GPS or an authorized Hemisphere GPS representative
To activate the application on a Hemisphere GPS receiver:
1.
Connect the Hemisphere GPS receiver to the serial COM port on the computer.
2.
Start SLXMon on the computer.
3.
Select File > Connect and then select the appropriate Comm Port and Baud Rate to open communication with the
receiver.
4.
Select Control > View Command Page.
5.
In the Receiver Command Page window type $JAPP in the Message box and then click Send.
6.
Confirm which applications are loaded onto the receiver and the order in which they appear in the Reply box.
Example Response (in Reply box):
$>JAPP,WAAS,DIFF
where WAAS (SBAS, EGNOS, MSAS) is the number one application (or application number 1) and DIFF (same as eDif) is the "other" application (or application number 2)
7.
If DIFF is listed as application number 2 in the $JAPP response then type the following command in the Message
box:
$JAPP,O
where 'O' is the "other" application in the example. This swaps the two applications so that DIFF is be the current
application.
42
Receiver Operation
8.
Type the following command in the Message box:
$JI
The first number in the response is the serial number of the receiver.
Example Response (in Reply box):
$>JI,810133,1,3,09031998,01/06/1998,12/31/2018,3.5,31
The serial number is 810133. You will need to provide it to Hemisphere GPS with your request for an e-Dif
subscription code.
9.
Type the following command in the Message box after receiving the subscription code from Hemisphere GPS:
$JK,nnnn
where 'nnnn' is the subscription number. The receiver will respond with "subscription accepted."
Interpreting the $JI and $JK 'Date'/Subscription Codes
Subscriptions codes enable GPS differential correction sources on your receiver. When discussing them it is important to
understand the following.
•
The YYYY component of a MM/DD/YYYY formatted date—returned by both the JI and JK commands—is not always
just the year component of that date. When a date’s year starts with 30, only the 30 represents the year - and that
year is 3000. A subscription expiration date of 01/01/3000 effectively means there is no expiration date.
•
The last two digits of the 30YY 'date' represent the data output rate (in Hz) and the GPS differential correction
sources that have been subscribed to and are therefore enabled on your receiver. Hemisphere GPS refers to these
two digits as the "additive code" (see Understanding Additive Codes).
•
The 30 and the 00 in the 'year' 3000, then, represents "Expires 3000 (so effectively does not expire), the data rate is
10 Hz, and SBAS is enabled." The 'year' 3015 indicates "Expires 3000, the data rate is 20 Hz and differential
correction sources SBAS/e-Dif/RTK and L-Dif have been subscribed to and are enabled."
Below is an example of the $JI command response, part of which is the subscription start and expiration dates (the date codes
are shaded).
$>JI,12838,1,7,26022003,01/01/1900,01/01/3000,6.8Hx,38
43
Hemisphere GPS Technical Reference v1.02
Understanding Additive Codes
Tables 1 and 2 below provide subscription information for Crescent and Eclipse receivers, where the data rate and
subscription are indicated by the 'date' returned by the JK and JI commands. For Eclipse II receivers, refer to Eclipse II
Subscription Codes. The part of the date that indicates the data rate and subscription code is called the "additive code." The
last two digits in the subscription expiration date’s ‘year’ comprise the additive codes, that is, the current data output rate from
the receiver in Hz, plus the subscriptions—the enabled GPS differential correction sources.
Table 3 outlines the components of the Crescent, Eclipse, and Eclipse II additive codes. The subscription codes have different
additive components for Crescent, Eclipse, and Eclipse II.
Table 1: Crescent Subscription Codes
Date Code
(Additive Code)
Hex
Code
Maximum
Data
Rate
Subscription Description
3000 (0)
HEX 0
10 Hz
SBAS enabled
3001 (1)
HEX 1
20 Hz
SBAS enabled
3002 (0+2)
HEX 2
10 Hz
SBAS, e-Dif enabled
3003 (1+2)
HEX 3
20 Hz
SBAS, e-Dif enabled
3004 (0+4)
HEX 4
10 Hz
SBAS, RTK Rover enabled
3005 (1+4)
HEX 5
20 Hz
SBAS, RTK Rover enabled
3006 (0+2+4)
HEX 6
10 Hz
SBAS, RTK Rover, e-Dif enabled
3007 (1+2+4)
HEX 7
20 Hz
SBAS, RTK Rover, e-Dif enabled
3008 (0+8)
HEX 8
10 Hz
SBAS, L-Dif Rover, L-Dif Base, RTK Base enabled
3009 (1+8)
HEX 9
20 Hz
SBAS, L-Dif Rover, L-Dif Base, RTK Base enabled
3010 (0+2+8)
HEX A
10 Hz
SBAS, L-Dif Rover, L-Dif Base, RTK Base, e-Dif enabled
3011 (1+2+8)
HEX B
20 Hz
SBAS, L-Dif Rover, L-Dif Base, RTK Base, e-Dif enabled
3012 (0+4+8)
HEX C
10 Hz
SBAS, L-Dif Rover, L-Dif Base, RTK Rover, RTK Base enabled
3013 (1+4+8)
HEX D
20 Hz
SBAS, L-Dif Rover, L-Dif Base, RTK Rover, RTK Base enabled
3014 (0+2+4+8)
HEX E
10 Hz
SBAS, L-Dif Rover, L-Dif Base, RTK Rover, RTK Base, e-Dif enabled
3015 (1+2+4+8)
HEX F
20 Hz
SBAS, L-Dif Rover, L-Dif Base, RTK Rover, RTK Base, e-Dif enabled
Table 2: Eclipse Subscription Codes
Date Code
(Additive
Code)
Hex
Code
Maximum
Data
Rate
Subscription Description
3000 (0)
HEX 0
10 Hz
SBAS, OmniSTAR enabled
3001 (1)
HEX 1
20 Hz
SBAS, OmniSTAR enabled
3004 (0+4)
HEX 4
10 Hz
SBAS, OmniSTAR, RTK Rover, RTK Base, Raw L1/L2 data enabled
3005 (1+4)
HEX 5
20 Hz
SBAS, OmniSTAR, RTK Rover, RTK Base, Raw L1/L2 data enabled
44
Receiver Operation
Table 2: Eclipse Subscription Codes
Date Code
(Additive
Code)
Hex
Code
Maximum
Data
Rate
Subscription Description
3008 (0+8)
HEX 8
10 Hz
SBAS, OmniSTAR, RTK Base, Raw L1/L2 data enabled
3009 (1+8)
HEX 9
20 Hz
SBAS, OmniSTAR, RTK Base, Raw L1/L2 data enabled
3016 (0+16)
HEX 10
10 Hz
SBAS, OmniSTAR, Raw L1/L2 data enabled
3017 (1+16)
HEX 11
20 Hz
SBAS, OmniSTAR, Raw L1/L2 data enabled
Eclipse II Subscription Codes (go here)
Table 3: Crescent, Eclipse, and Eclipse II Additive Codes Components
Crescent
Code
Description
Eclipse
Code
Description
Eclipse II
Code
Description
0
10 Hz
0
10 Hz
0
10 Hz
1
20 Hz
1
20 Hz
1
20 Hz
2
e-Dif
2
n/a
2
e-Dif
4
L-Dif Rover, L-Dif
Base, RTK Rover
4
Raw L1/L2 Data, RTK
Base, RTK Rover
4
RTK Rover
(minimum L1 only)
8
RTK Base
8
Raw L1/L2 Data, RTK
Base
8
RTK Base
(minimum L1 only)
16
n/a
16
Raw L1/L2 Data
16
Raw Data
(minimum L1 only)
32
n/a
32
n/a
32
L2 signals
64
n/a
64
n/a
64
GLONASS signals
(minimum L1 only)
Crescent Additive Code Examples
•
10 Hz (SBAS), e-Dif, and RTK is 0+2+4 = 6 (so 3006)
•
20 Hz (SBAS), e-Dif, and RTK is 1+2+4 = 7 (so 3007)
Comparing the JI and JK Responses
In the following Crescent examples, the date code is shaded.
•
JI query date code example:
$>JI,311077,1,7,04102005,01/01/1900,01/01/3000,6.8Hx,46
•
JK date code example:
$>JK,01/01/3000,0,(1, 2, 5 or no number)
In the JK examples, the second to last digit of the date code (,0, in the example) is the hex value (the second column of Table
2).
45
Hemisphere GPS Technical Reference v1.02
The last digit to the right (1, 2, 5 or no number) is the output rate in Hertz and indicates a downgrade from the default 10 Hertz.
Thus, if 1, 2 or 5 does not appear, the output rate is the default 10 Hz.
The date codes are identical in either query and are directly related to each other. The last digit in the JK query is the
hexadecimal equivalent of the last two digits in the date code. The following example further illustrate this. The date code is
shaded.
Note: The JI response provides the decimal date code while the JK response provides both the decimal date code and the
hex date code.
JI query date code example:
$>JI,311077,1,7,04102005,01/01/1900,01/01/3015,6.8Hx,46
JK date code example:
$>JK,01/01/3015,F
In this example, the date code is showing 15 in the last two digits. Therefore, the Hex number following the date code in the JK
query is F as shown in the last row of Table 1.
46
Receiver Operation
Eclipse II Subscription Codes
Use the tables below locate your Eclipse II subscription code and its features.
1
2
0x01
20Hz
4
8
16
32
64
0x02
0x04
0x08
0x10
0x20
0x40
eDiff
RTK Rover,
RTK Base,
Raw Out
RTK Base,
Raw Out
Raw Out
L2
GLONASS
Date Code (Additive Code)
3000
Y
Y
3001
Y
3002
Y
3003
Y
3004
Y
3005
Y
Y
3006
Y
Y
3007
Y
Y
Y
3008
Y
3009
Y
Y
3010
Y
Y
3011
Y
Y
3012
Y
Y
3013
Y
Y
Y
3014
Y
Y
Y
3015
Y
Y
Y
Y
Y
3016
Y
3017
Y
Y
3018
Y
Y
3019
Y
Y
3020
Y
Y
3021
Y
Y
Y
3022
Y
Y
Y
3023
Y
Y
3024
Y
Y
3025
Y
Y
Y
3026
Y
Y
Y
3027
Y
Y
Y
3028
Y
Y
Y
3029
Y
Y
Y
Y
3030
Y
Y
Y
Y
3031
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
3032
Y
3033
47
Hemisphere GPS Technical Reference v1.02
1
2
0x01
20Hz
Y
4
8
16
32
64
0x02
0x04
0x08
0x10
0x20
0x40
eDiff
RTK Rover,
RTK Base,
Raw Out
RTK Base,
Raw Out
Raw Out
L2
GLONASS
Y
Y
3034
Y
Y
3035
Y
Y
3036
Y
Y
3037
Y
Y
Y
3038
Y
Y
Y
3039
Y
Y
3040
Y
Y
3041
Y
Y
Y
3042
Y
Y
Y
3043
Y
Y
Y
3044
Y
Y
Y
3045
Y
Y
Y
Y
3046
Y
Y
Y
Y
3047
Y
Y
3048
Y
Y
3049
Y
Y
Y
3050
Y
Y
Y
3051
Y
Y
Y
3052
Y
Y
Y
3053
Y
Y
Y
Y
3054
Y
Y
Y
Y
3055
Y
Y
Y
3056
Y
Y
Y
3057
Y
Y
Y
Y
3058
Y
Y
Y
Y
3059
Y
Y
Y
Y
3060
Y
Y
Y
Y
3061
Y
Y
Y
Y
Y
3062
Y
Y
Y
Y
Y
3063
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
3064
Y
3065
Y
Y
3066
Y
Y
3067
Y
Y
3068
Y
Y
3069
Y
Y
3070
Y
Y
Y
Y
48
Date Code (Additive Code)
Receiver Operation
1
2
4
8
16
32
64
0x01
0x02
0x04
0x08
0x10
0x20
0x40
20Hz
eDiff
RTK Rover,
RTK Base,
Raw Out
RTK Base,
Raw Out
Raw Out
L2
GLONASS
Date Code (Additive Code)
Y
Y
Y
Y
3071
Y
Y
3072
Y
Y
3073
Y
Y
Y
3074
Y
Y
Y
3075
Y
Y
Y
3076
Y
Y
Y
3077
Y
Y
Y
Y
3078
Y
Y
Y
Y
3079
Y
Y
3080
Y
Y
3081
Y
Y
Y
3082
Y
Y
Y
3083
Y
Y
Y
3084
Y
Y
Y
3085
Y
Y
Y
Y
3086
Y
Y
Y
Y
3087
Y
Y
Y
3088
Y
Y
Y
3089
Y
Y
Y
Y
3090
Y
Y
Y
Y
3091
Y
Y
Y
Y
3092
Y
Y
Y
Y
3093
Y
Y
Y
Y
Y
3094
Y
Y
Y
Y
Y
3095
Y
Y
3096
Y
Y
3097
Y
Y
Y
3098
Y
Y
Y
3099
Y
Y
Y
3100
Y
Y
Y
3101
Y
Y
Y
Y
3102
Y
Y
Y
Y
3103
Y
Y
Y
3104
Y
Y
Y
3105
Y
Y
Y
Y
3106
Y
Y
Y
Y
3107
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
49
Hemisphere GPS Technical Reference v1.02
1
2
0x01
20Hz
4
8
16
32
64
0x02
0x04
0x08
0x10
0x20
0x40
eDiff
RTK Rover,
RTK Base,
Raw Out
RTK Base,
Raw Out
Raw Out
L2
GLONASS
Date Code (Additive Code)
Y
Y
Y
Y
3108
Y
Y
Y
Y
3109
Y
Y
Y
Y
Y
3110
Y
Y
Y
Y
Y
3111
Y
Y
Y
3112
Y
Y
Y
3113
Y
Y
Y
Y
3114
Y
Y
Y
Y
3115
Y
Y
Y
Y
3116
Y
Y
Y
Y
3117
Y
Y
Y
Y
Y
3118
Y
Y
Y
Y
Y
3119
Y
Y
Y
Y
3120
Y
Y
Y
Y
3121
Y
Y
Y
Y
Y
3122
Y
Y
Y
Y
Y
3123
Y
Y
Y
Y
Y
3124
Y
Y
Y
Y
Y
3125
Y
Y
Y
Y
Y
Y
3126
Y
Y
Y
Y
Y
Y
3127
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Date
Code
Hex
Code
Update
Rate
3000
0
10Hz
L1, GPS
3001
1
20Hz
L1, GPS
3002
2
10Hz
L1, GPS, eDiff
3003
3
20Hz
L1, GPS, eDiff
3004
4
10Hz
L1, GPS, RTK Rover, RTK Base, Raw Out
3005
5
20Hz
L1, GPS, RTK Rover, RTK Base, Raw Out
3006
6
10Hz
L1, GPS, eDiff, RTK Rover, RTK Base, Raw Out
3007
7
20Hz
L1, GPS, eDiff, RTK Rover, RTK Base, Raw Out
3008
8
10Hz
L1, GPS, RTK Base, Raw Ou
3009
9
20Hz
L1, GPS, RTK Base, Raw Ou
3010
A
10Hz
L1, GPS, eDiff, RTK Base, Raw Ou
3011
B
20Hz
L1, GPS, eDiff, RTK Base, Raw Ou
3012
C
10Hz
L1, GPS, RTK Rover, RTK Base, Raw Out
50
Subscription Description
Receiver Operation
Date
Code
Hex
Code
Update
Rate
3013
D
20Hz
L1, GPS, RTK Rover, RTK Base, Raw Out
3014
E
10Hz
L1, GPS, eDiff, RTK Rover, RTK Base, Raw Out
3015
F
20Hz
L1, GPS, eDiff, RTK Rover, RTK Base, Raw Out
3016
10
10Hz
L1, GPS, Raw Out
3017
11
20Hz
L1, GPS, Raw Out
3018
12
10Hz
L1, GPS, eDiff, Raw Out
3019
13
20Hz
L1, GPS, eDiff, Raw Out
3020
14
10Hz
L1, GPS, RTK Rover, RTK Base, Raw Out
3021
15
20Hz
L1, GPS, RTK Rover, RTK Base, Raw Out
3022
16
10Hz
L1, GPS, eDiff, RTK Rover, RTK Base, Raw Out
3023
17
20Hz
L1, GPS, eDiff, RTK Rover, RTK Base, Raw Out
3024
18
10Hz
L1, GPS, RTK Base, Raw Ou
3025
19
20Hz
L1, GPS, RTK Base, Raw Ou
3026
1A
10Hz
L1, GPS, eDiff, RTK Base, Raw Ou
3027
1B
20Hz
L1, GPS, eDiff, RTK Base, Raw Ou
3028
1C
10Hz
L1, GPS, RTK Rover, RTK Base, Raw Out
3029
1D
20Hz
L1, GPS, RTK Rover, RTK Base, Raw Out
3030
1E
10Hz
L1, GPS, eDiff, RTK Rover, RTK Base, Raw Out
3031
1F
20Hz
L1, GPS, eDiff, RTK Rover, RTK Base, Raw Out
3032
20
10Hz
L1/L2, GPS
3033
21
20Hz
L1/L2, GPS
3034
22
10Hz
L1/L2, GPS, eDiff
3035
23
20Hz
L1/L2, GPS, eDiff
3036
24
10Hz
L1/L2, GPS, RTK Rover, RTK Base, Raw Out
3037
25
20Hz
L1/L2, GPS, RTK Rover, RTK Base, Raw Out
3038
26
10Hz
L1/L2, GPS, eDiff, RTK Rover, RTK Base, Raw Out
3039
27
20Hz
L1/L2, GPS, eDiff, RTK Rover, RTK Base, Raw Out
3040
28
10Hz
L1/L2, GPS, RTK Base, Raw Ou
3041
29
20Hz
L1/L2, GPS, RTK Base, Raw Ou
3042
2A
10Hz
L1/L2, GPS, eDiff, RTK Base, Raw Ou
3043
2B
20Hz
L1/L2, GPS, eDiff, RTK Base, Raw Ou
3044
2C
10Hz
L1/L2, GPS, RTK Rover, RTK Base, Raw Out
3045
2D
20Hz
L1/L2, GPS, RTK Rover, RTK Base, Raw Out
3046
2E
10Hz
L1/L2, GPS, eDiff, RTK Rover, RTK Base, Raw Out
3047
2F
20Hz
L1/L2, GPS, eDiff, RTK Rover, RTK Base, Raw Out
3048
30
10Hz
L1/L2, GPS, Raw Out
3049
31
20Hz
L1/L2, GPS, Raw Out
3050
32
10Hz
L1/L2, GPS, eDiff, Raw Out
3051
33
20Hz
L1/L2, GPS, eDiff, Raw Out
Subscription Description
51
Hemisphere GPS Technical Reference v1.02
Date
Code
Hex
Code
Update
Rate
3052
34
10Hz
L1/L2, GPS, RTK Rover, RTK Base, Raw Out
3053
35
20Hz
L1/L2, GPS, RTK Rover, RTK Base, Raw Out
3054
36
10Hz
L1/L2, GPS, eDiff, RTK Rover, RTK Base, Raw Out
3055
37
20Hz
L1/L2, GPS, eDiff, RTK Rover, RTK Base, Raw Out
3056
38
10Hz
L1/L2, GPS, RTK Base, Raw Ou
3057
39
20Hz
L1/L2, GPS, RTK Base, Raw Ou
3058
3A
10Hz
L1/L2, GPS, eDiff, RTK Base, Raw Ou
3059
3B
20Hz
L1/L2, GPS, eDiff, RTK Base, Raw Ou
3060
3C
10Hz
L1/L2, GPS, RTK Rover, RTK Base, Raw Out
3061
3D
20Hz
L1/L2, GPS, RTK Rover, RTK Base, Raw Out
3062
3E
10Hz
L1/L2, GPS, eDiff, RTK Rover, RTK Base, Raw Out
3063
3F
20Hz
L1/L2, GPS, eDiff, RTK Rover, RTK Base, Raw Out
3064
40
10Hz
L1, GPS/GLONASS
3065
41
20Hz
L1, GPS/GLONASS
3066
42
10Hz
L1, GPS/GLONASS, eDiff
3067
43
20Hz
L1, GPS/GLONASS, eDiff
3068
44
10Hz
L1, GPS/GLONASS, RTK Rover, RTK Base, Raw Out
3069
45
20Hz
L1, GPS/GLONASS, RTK Rover, RTK Base, Raw Out
3070
46
10Hz
L1, GPS/GLONASS, eDiff, RTK Rover, RTK Base, Raw Out
3071
47
20Hz
L1, GPS/GLONASS, eDiff, RTK Rover, RTK Base, Raw Out
3072
48
10Hz
L1, GPS/GLONASS, RTK Base, Raw Ou
3073
49
20Hz
L1, GPS/GLONASS, RTK Base, Raw Ou
3074
4A
10Hz
L1, GPS/GLONASS, eDiff, RTK Base, Raw Ou
3075
4B
20Hz
L1, GPS/GLONASS, eDiff, RTK Base, Raw Ou
3076
4C
10Hz
L1, GPS/GLONASS, RTK Rover, RTK Base, Raw Out
3077
4D
20Hz
L1, GPS/GLONASS, RTK Rover, RTK Base, Raw Out
3078
4E
10Hz
L1, GPS/GLONASS, eDiff, RTK Rover, RTK Base, Raw Out
3079
4F
20Hz
L1, GPS/GLONASS, eDiff, RTK Rover, RTK Base, Raw Out
3080
50
10Hz
L1, GPS/GLONASS, Raw Out
3081
51
20Hz
L1, GPS/GLONASS, Raw Out
3082
52
10Hz
L1, GPS/GLONASS, eDiff, Raw Out
3083
53
20Hz
L1, GPS/GLONASS, eDiff, Raw Out
3084
54
10Hz
L1, GPS/GLONASS, RTK Rover, RTK Base, Raw Out
3085
55
20Hz
L1, GPS/GLONASS, RTK Rover, RTK Base, Raw Out
3086
56
10Hz
L1, GPS/GLONASS, eDiff, RTK Rover, RTK Base, Raw Out
3087
57
20Hz
L1, GPS/GLONASS, eDiff, RTK Rover, RTK Base, Raw Out
3088
58
10Hz
L1, GPS/GLONASS, RTK Base, Raw Ou
3089
59
20Hz
L1, GPS/GLONASS, RTK Base, Raw Ou
3090
5A
10Hz
L1, GPS/GLONASS, eDiff, RTK Base, Raw Ou
52
Subscription Description
Receiver Operation
Date
Code
Hex
Code
Update
Rate
3091
5B
20Hz
L1, GPS/GLONASS, eDiff, RTK Base, Raw Ou
3092
5C
10Hz
L1, GPS/GLONASS, RTK Rover, RTK Base, Raw Out
3093
5D
20Hz
L1, GPS/GLONASS, RTK Rover, RTK Base, Raw Out
3094
5E
10Hz
L1, GPS/GLONASS, eDiff, RTK Rover, RTK Base, Raw Out
3095
5F
20Hz
L1, GPS/GLONASS, eDiff, RTK Rover, RTK Base, Raw Out
3096
60
10Hz
L1/L2, GPS/GLONASS
3097
61
20Hz
L1/L2, GPS/GLONASS
3098
62
10Hz
L1/L2, GPS/GLONASS, eDiff
3099
63
20Hz
L1/L2, GPS/GLONASS, eDiff
3100
64
10Hz
L1/L2, GPS/GLONASS, RTK Rover, RTK Base, Raw Out
3101
65
20Hz
L1/L2, GPS/GLONASS, RTK Rover, RTK Base, Raw Out
3102
66
10Hz
L1/L2, GPS/GLONASS, eDiff, RTK Rover, RTK Base, Raw Out
3103
67
20Hz
L1/L2, GPS/GLONASS, eDiff, RTK Rover, RTK Base, Raw Out
3104
68
10Hz
L1/L2, GPS/GLONASS, RTK Base, Raw Ou
3105
69
20Hz
L1/L2, GPS/GLONASS, RTK Base, Raw Ou
3106
6A
10Hz
L1/L2, GPS/GLONASS, eDiff, RTK Base, Raw Ou
3107
6B
20Hz
L1/L2, GPS/GLONASS, eDiff, RTK Base, Raw Ou
3108
6C
10Hz
L1/L2, GPS/GLONASS, RTK Rover, RTK Base, Raw Out
3109
6D
20Hz
L1/L2, GPS/GLONASS, RTK Rover, RTK Base, Raw Out
3110
6E
10Hz
L1/L2, GPS/GLONASS, eDiff, RTK Rover, RTK Base, Raw Out
3111
6F
20Hz
L1/L2, GPS/GLONASS, eDiff, RTK Rover, RTK Base, Raw Out
3112
70
10Hz
L1/L2, GPS/GLONASS, Raw Out
3113
71
20Hz
L1/L2, GPS/GLONASS, Raw Out
3114
72
10Hz
L1/L2, GPS/GLONASS, eDiff, Raw Out
3115
73
20Hz
L1/L2, GPS/GLONASS, eDiff, Raw Out
3116
74
10Hz
L1/L2, GPS/GLONASS, RTK Rover, RTK Base, Raw Out
3117
75
20Hz
L1/L2, GPS/GLONASS, RTK Rover, RTK Base, Raw Out
3118
76
10Hz
L1/L2, GPS/GLONASS, eDiff, RTK Rover, RTK Base, Raw Out
3119
77
20Hz
L1/L2, GPS/GLONASS, eDiff, RTK Rover, RTK Base, Raw Out
3120
78
10Hz
L1/L2, GPS/GLONASS, RTK Base, Raw Ou
3121
79
20Hz
L1/L2, GPS/GLONASS, RTK Base, Raw Ou
3122
7A
10Hz
L1/L2, GPS/GLONASS, eDiff, RTK Base, Raw Ou
3123
7B
20Hz
L1/L2, GPS/GLONASS, eDiff, RTK Base, Raw Ou
3124
7C
10Hz
L1/L2, GPS/GLONASS, RTK Rover, RTK Base, Raw Out
3125
7D
20Hz
L1/L2, GPS/GLONASS, RTK Rover, RTK Base, Raw Out
3126
7E
10Hz
L1/L2, GPS/GLONASS, eDiff, RTK Rover, RTK Base, Raw Out
3127
7F
20Hz
L1/L2, GPS/GLONASS, eDiff, RTK Rover, RTK Base, Raw Out
Subscription Description
53
Hemisphere GPS Technical Reference v1.02
Determining the Receiver Type and Current Application
To determine the current receiver type, use the JT command. Table 1 shows the receiver type indicated by the JT response.
Table 1: $JT Response and Receiver Type
$JT Response
Receiver Type
SX1x
SX-1
SX2x
Crescent
SLXx
SLX2/SLX3
DF2x
Eclipse
DF3x
Eclipse II
MF3x
miniEclipse
The 'x' in the responses represents the receiver’s current application. For example, if x = i, as in SX2i, 'i' is the application code
for e-Dif.
Table 2 shows the application for the application code in the JT response.
Table 2: $JT Response and Application
$JT Responses with Application Code
Receiver Application
r
RTK rover
b
RTK base
i
e-Dif
g
OmniSTAR
g
WAAS
g
Standalone
a
Vector
54
Receiver Operation
Configuring the Receiver
You can configure all aspects of receiver operation through any serial port using NMEA 0183 commands. You can:
•
Select one of the two on-board applications
o
Two applications may be loaded at the same time, but only one can be active
o
You can select the active application through serial commands or through menu options on products with
displays
•
Set the baud rate of both communication ports
•
Select NMEA 0183 data messages to output on the serial ports and select the output rate of each message
•
Set the maximum differential age cut-off
•
Set the satellite elevation angle cut-off mask
The appropriate commands are described in Commands and Messages.
55
Hemisphere GPS Technical Reference v1.02
Configuring the Data Message Output
In addition to its differential-only Port D, the receiver features three primary bi-directional ports referred to as A, B, and C. You
can configure GPS data messages for all three ports by sending NMEA 0183 commands to the receiver module through all its
communication ports. You can configure the output of Port B through A, for instance, and vice versa. The JASC NMEA
message allows you to turn the messages on or off as required.
Note: For receivers that have a USB port that supports writing to a USB flash drive you can specify Port T as a port to receive
messages.
In the examples below where you can specify the port, use 'PORTT' to specify Port T.
'THIS' Port and the 'OTHER' Port
The NMEA 0183 interface for Port A and B both use 'THIS' and 'OTHER' terminology.
•
THIS port
The port you are currently connected to for inputting commands. To get the data output through THIS port it is not
necessary to specify 'this' (see Example 1 below).
•
The OTHER port
To specify the OTHER port for the data output, you need to include 'OTHER' in the command. See the two examples
following which are both based on you being connected to Port B.
Example 1:
To turn the GPGGA message on at 5 Hz on Port B, use the following command:
$JASC,GPGGA,5<CR><LF>
Because B is THIS it does not have to be specified.
Example 2:
To turn the GPGGA message on at an output rate of 5 Hz on Port A, use the following command:
$JASC,GPGGA,5,OTHER<CR><LF>
Because B is THIS and A is OTHER, you have to specify OTHER. In contrast, when turning messages on or off on Port C
from Port A or Port B, you must specify Port C in the command.
Example 3:
To turn the GPGLL NMEA 0183 message on at 10 Hz on Port C, use the following command:
$JASC,GPGLL,10,PORTC<CR><LF>
As with Port A and B, when communicating directly with Port C, you do not need to specify anything at the end of the
message. See Commands and Messages for more information.
56
Receiver Operation
Saving the Receiver Configuration
Each time the configuration of the receiver is changed, the new configuration should be saved so the receiver does not have to
be reconsidered for the next power cycle.
To save the settings:
•
Issue the JSAVE command. The receiver records the current configuration to non-volatile memory. The receiver
indicates when the save process, which takes about five seconds, is complete.
Using Port D for RTCM Input
The receiver has a port designed to accommodate externally supplied corrections input according to the RTCM SC-104
protocol. Port D provides this functionality although it has been fixed to operate at a baud rate of 9600 (8 data bits, no parity,
and 1 stop bit, that is, 8-N-1).
To use Port D of the receiver for correction input, you must set the receiver to operate in beacon differential mode using the
following command:
$JDIFF,BEACON<CR><LF>
This command was designed to “turn on” Port D differential operation in our products because many use the Hemisphere GPS
SBX beacon module interfaced to Port D.
Note: The receiver is compatible with RTCM SC-104 message types 1-3, 5-7, 9 and 16 although not all the message types
contain differential data.
To return to using SBAS as the correction source, send the following command to the receiver:
$JDIFF,WAAS<CR><LF>
See Commands and Messages for detailed information on NMEA 0183 messages supported by the receiver.
57
Hemisphere GPS Technical Reference v1.02
SBX-4 Database Mode
Enabling Database Mode
Database mode is automatically enabled when the SBX-4 receives a valid RMC message on Port 0. This requires the baud
rate of Port 0 to be the same as the corresponding GPS receiver port.
Performance in Database Mode
In most installations Database mode will result in faster initial acquisition and better GPS accuracy compared to Auto mode.
In some installations Database mode may not work as well as Auto mode for the following reasons:
•
The closest station is not in the station database and the SBX-4 has not yet received a Type7 Almanac message.
Most stations now broadcast the Almanac message every ten minutes. Assuming the SBX-4 can tune to a
surrounding station and receive a Type7 message, it will update the station database and automatically retune to the
closest station.
•
Signal quality in the area is poor. IEC61108-4 requires the receiver to switch away from a station when WER rises
above 10%. For installations that do not need to comply with IEC61108-4 this threshold can be increased as usable
corrections can be obtained for word error rates up to 50%.
Available Production Configuration Settings
Disable the automatic switch to Database mode:
$PCSI,8,NITRAM,A
Enable weak signal tracking (WER of 50%):
$PCSI,8,NITRAM,W
Enable legacy Q value output (in place of WER):
$PCSI,8,NITRAM,Q
Set SBX-4 to factory defaults:
$PCSI,8,NITRAM,E
58
PocketMAX Utility
PocketMAX Overview
PocketMax3 is a freely available utility designed for use with several Hemisphere GPS products, including:
•
Crescent OEM
•
Eclipse OEM
•
Eclipse II OEM
•
miniEclipse OEM
•
Crescent Vector OEM
•
Crescent Vector II OEM
•
Crescent A100
•
Crescent R100 Series
•
Crescent XF100 Series
•
Crescent V100 series
•
Crescent VS100 series
•
Eclipse A220 Series
•
Eclipse R220
•
Eclipse II R320
PocketMax3 was not designed specifically for any one product alone (it supports features not offered by every product);
however, the interface may be used for all I/O operations. PocketMax3 runs on the Windows .NET framework, version 3.5 or
later, allowing it to operate on several Windows platforms (Windows 2000, ME, XP, Vista, 7, Mobile, etc).
This software offers you the following flexibility:
•
Tune your beacon, WAAS, OmniSTAR and GLONASS receivers and monitor reception
•
Configure GPS and GNSS message output and port settings
•
Configure and monitor an RTK base station
•
Configure and monitor Vector related settings
•
Record various types of data
The current version of PocketMax3 PC can be downloaded from the Hemisphere GPS website, or it can be made available to
you by contacting Hemisphere GPS. After saving the PocketMax3 executable to your computer, start the program by doubleclicking the file name or icon.
You will need to have the Windows .NET framework installed on your PC or mobile device. Follow the link for a PC install from
the same webpage with the PocketMax3 download. Once you have the PocketMax3 executable appropriate for your mobile
device’s operating system, you can copy it over to your mobile device to whichever folder you wish. To start the program,
navigate to the executable on your mobile device and tap the file.
Note: This technical reference provides summary information about what you can use PocketMax3 for. For details on how you
use PocketMAX—including navigating through the menus options and tabs—refer to the PocketMAX User Guide available for
download from www.hemispheregps.com.
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Hemisphere GPS Technical Reference v1.02
PocketMAX Key Uses
Use PocketMAX to:
•
Tune your GPS, Beacon, SBAS and OmniSTAR receiver
•
Monitor GPS, Beacon, SBAS, and OmniSTAR reception
•
Configure GPS message output and port settings
•
Configure and monitor Vector-related settings
•
Record various types of data
Because PocketMAX PC and PocketMAX were not designed specifically for one receiver, they support features not offered by
some receivers, such as tracking of the OmniSTAR differential service and display of our Vector product’s true heading.
However, the interface may be used for all I/O operations.
PocketMAX PC runs on any PC with Windows 95, 98, or NT 4.0+ (Windows 2000 and Windows XP). Screen resolution of
800x600 or greater is recommended. One of the receiver’s serial ports must be connected to a COM port on the computer.
You can download the current version of PocketMAX PC, or PocketMAX, from www.hemispheregps.com.
PocketMAX Startup
When you start PocketMAX you’ll first briefly see the Welcome screen then the (untitled) startup configuration screen. Both are
shown below.
Use the startup configuration screen to specify the COM port and baud rate of the receiver.
60
PocketMAX Utility
PocketMAX Features
The following tables summarize the screen content for the menu options and their respective tabs.
•
GPS tabs
•
Differential Source tabs
o
SBAS
o
BEAC
o
LBND (OmniSTAR)
o
e-Dif
o
L-Dif BASE
•
TMNL (Terminal) tabs
•
LOGS tabs
•
HDG (Heading) tabs
PocketMAX GPS Tabs
Tab
Description of Content/Use
Pos’n (Position)
All the main position information including latitude and longitude, altitude, speed and
precision. You can select a differential source from within this tab as well as through the
differential source menu.
Sats (Satellite)
Provides a sky plot of viewable satellites, how many satellites the receiver is tracking, the
PRN numbers of the satellites are being tracked and the BER (Bit Error Rate) of the
differential source.
Setup
Change the configuration of the receiver including turning NMEA messages on or off, the
elevation mask, the maximum COAST age and the baud rates.
Precision
Provides a graphical representation of horizontal accuracy in the from of an error ellipse. It
also provides configurable numerical precision in northing, easting, and altitude components.
Plot
Plots the northing and easting error over time and enables you to adjust the scale and
timeline. You can monitor performance over a time period with respect to either a known
coordinate or an arbitrary one.
About
Provides current firmware information.
Differential Source Tabs
Differential source tabs can be any of the following:
SBAS Tabs
Tab
Description of Content/Use
Status
Provides details of the satellites being used in the SBAS differential system, which covers both
WAAS and EGNOS. The PRNs, longitudes, elevation, azimuth, and the BER of the satellites being
tracked are also shown.
Plot
Charts and gives a bar graph of the BER of up to two SBAS Satellites being tracked.
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Hemisphere GPS Technical Reference v1.02
BEAC Tabs
Tab
Description of Content/Use
Status
Provides details of the beacon station providing corrections, including the name (if known), the
frequency, the MSK rate, and the SS and SNR values.
Tune
Gives you the option to automatically tune to the strongest signal, specifying a frequency or MSK bit
rate, or selecting a station by region.
Plot
Charts the signal strength, the SNR or the frequency of the beacon signal.
LBND (OmniSTAR) Tabs
Tab
Description of Content/Use
Status
Provides the name (if available), the frequency and data rate of the L-Band satellite currently being
used. Also displays the BER, the location and status of the satellite.
Tune
Provides the name (if available), the frequency and data rate of the L-Band satellite currently being
used and provides the option of tuning manually by frequency and data rate, automatically or by the
name of the satellite.
Subscription
Provides the begin and expiration dates of the subscription as well as the serial number of the unit
and the countdown timer (gives you the amount of time you have left for your subscription).
e-Dif Tabs
Tab
Description of Content/Use
Setup
Provides options to configure the receiver for e-Dif operation. For receivers with valid subscriptions,
this screen enables you to initialize based on a multiple run - unknown control point; multiple run known reference point (entered as the latitude, longitude and height of a reference position); or a
single run.
L-Dif BASE Tabs
Tab
Description of Content/Use
Setup
Provides options to set the latitude, longitude and height of a reference position and to select the
port the receiver uses to connect to a radio that broadcasts local differential corrections.
TMNL Tabs
Tab
Description of Content/Use
Terminal
Provides direct terminal access to the receiver for issuing commands and observing responses.
Hot Keys
Enables you to set up frequently used commands and assign them to the buttons in the Terminal
tab. There are four levels of hot key, each with nine buttons giving you thirty-six shortcut keys for
issuing commands.
62
PocketMAX Utility
LOGS Tabs
Tab
Description of Content/Use
NMEA
Enables you to set up NMEA messages to be logged.
Raw Data
Enables you to log the raw binary Bin95 and Bin96 messages for post-processing.
Binary
Enables you to log a variety of binary messages.
Points
Enables you to log a point each time you press the Log Point button.
Polygon
Enables you to log polygons and displays the enclosed area.
HDG Tabs
Tab
Description of Content/Use
Status
Enables you to set up NMEA messages to be logged.
Setup
Enables you to log the raw binary Bin95 and Bin96 messages for post-processing.
Plot
Enables you to log a variety of binary messages.
63
Commands and Messages
The receiver supports a selection of NMEA 0183 messages, proprietary messages that conform to NMEA 0183 standards,
and Hemisphere GPS proprietary binary messages. It is your decision as a systems designer whether or not to support a
NMEA 0183-only software interface or a selection of both NMEA 0183 and binary messages.
All Crescent and Eclipse receivers are configured with NMEA 0183 commands and can output NMEA 0183 messages. In
addition to NMEA 0183, some receivers can be configured using NMEA 2000 commands and can output NMEA 2000
messages.
Commands
•
General operation and configuration commands
•
GPS commands
•
SBAS commands
•
e-Dif commands
•
Crescent Vector commands and messages
•
GLONASS commands and messages
•
DGPS base station commands
•
Local differential and RTK commands
•
Beacon receiver commands and messages
•
NMEA 0183 SBX queries
•
OmniSTAR commands
•
RAIM commands
Messages
•
Data messages
•
Binary messages
•
NMEA 2000 CAN messages
65
Hemisphere GPS Technical Reference v1.02
NMEA 0183 Message Format
NMEA 0183 messages (sentences) have the following format:
$XXYYY,ZZZ,ZZZ,ZZZ...*CC<CR><LF>
where:
Element
Description
$
Message header character
XX
NMEA 0183 talker field (GP indicates a GPS talker)
YYY
Type of GPS NMEA 0183 message
ZZZ
Variable length message fields
*CC
Checksum
<CR>
Carriage return
<LF>
Line feed
Null (empty) fields occur when there is no information for that field. You can use the JNP command to specify the number of
decimal places output in the GPGGA and GPGLL messages.
What does <CR><LF> mean?
The literal translation means "Carriage Return, Line Feed." They are terms used in computer programming languages to
describe the end of a line or string of text. If you are writing your own communication software for a receiver, see some of the
examples below. If you are already using a program such as PocketMAX, when you click to send a command to the receiver,
the program takes care of adding the carriage return and line feed to the end of the text string for you. If you are using
HyperTerminal or other terminal software, typically the Enter key on your keyboard is set to send the <CR><LF> pair. You may
need to define this in the setup section of the terminal software. Some software may treat the Enter key on your numeric
keypad differently than the main Enter key in the main QWERTY section of the keyboard – use the main Enter key for best
results.
Originally, the carriage return and line feed characters were for use with printers. The carriage return character would signal
the printer to send the print head back to the left edge of the page on the current line of text. The line feed command instructed
the printer to advance the paper one line. Today, electronics often use the carriage return and line feed instructions to signify
the end of a string of text, prompting the device to process the string and execute the instructions sent in the text string.
Electronics use different ways to represent the <CR><LF> characters. In ASCII numbers, <CR> is represented as 13 in
decimal, or 0D in hexadecimal. ASCII for <LF> is 10 decimal, or 0A hexadecimal. Some computer languages use different
ways to represent <CR><LF>. Unix and C language can use “\x0D\x0A". C language can also use “\r\n” in some instances.
Java may use CR+LF. In Unicode, carriage return is U+000D, and line feed is U+000A. It is advised to clearly understand how
to send these characters if you are writing your own interface software.
66
Commands and Messages
Command/Query/Message Types
General Operation and Configuration Commands
The following table lists the commands related to the general operation and configuration of the receiver.
Command
Description
JAIR
Specify how the receiver will respond to the dynamics associated with airborne
applications
JALT
Turn altitude aiding for the receiver on or off
JAPP
Specify or query receiver application firmware
JASC,D1
Set the RD1 diagnostic information message from the receiver to on or off
JASC,VIRTUAL
Configure the receiver to have RTCM data input on one port and output through the
other (when using an external correction source)
JBAUD
Specify the baud rates of the receiver or query the current setting
JBIN
Enable the output of the various binary messages supported by the receiver
JCONN
Create a virtual circuit between the A and B ports to enable communication through the
receiver to the device on the opposite port
JDIFF
Specify or query the differential mode of the receiver
JDIFFX,EXCLUDE
Specify the differential sources to be excluded from operating in a multi-diff application
JDIFFX,GNSSOUT
Specify GNSS output in correction formats or query the current setting
JDIFFX,INCLUDE
Specify the differential sources to be allowed to operate in a multi-diff application
JDIFFX,SOURCE
Query the receiver for the differential source
JDIFFX,TYPE
Query the receiver for the differential type
JFLASH,DIR
Display the files on a USB flash drive
JFLASH,FILE,CLOSE
Close an open file on a USB flash drive
JFLASH,FILE,NAME
Open a specific file, append to a specific file, or display the file name of the open file on a
USB flash drive
JFLASH,FILE,OPEN
Create and open a file with an automatically generated file name on a USB flash drive
JFLASH,FREESPACE
Display the free space in kilobytes (KB) on a USB flash drive
JFLASH,NOTIFY,CONNECT
Enable/disable the automatic response when a USB flash drive is inserted or removed (if
port is not specified the response will be sent to the port that issued the command)
JFLASH,QUERYCONNECT
Manually verify if a USB flash drive is connected or disconnected
JI
Display receiver information, such as its serial number and firmware version
JK
Subscribe the receiver to various options, such as higher update rates, e-Dif (or base
station capability) or L-Dif; or query for the current subscription expiration date when
running OmniSTAR application or the receiver subscription code when running all other
applications
JLIMIT
Set the threshold of estimated horizontal performance for which the DGPS position LED
is illuminated or query the current setting
JMODE
Query receiver for status of JMODE settings
JMODE,FOREST
Turn the higher gain functionality (for tracking under canopy) on/off or query the current
setting
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Command
Description
JMODE,GPSONLY
Set the receiver to use GPS data in the solution or query the current setting (if
GLONASS is available, setting to YES will cause the receiver to only use GPS data)
JMODE,L1ONLY
Set the receiver to use L1 data even if L2 data is available or query the current setting
JMODE,MIXED
Include satellites that do not have differential corrections in the solution
JMODE,NULLNMEA
Enable/disable output of NULL fields in NMEA 0183 messages when no there is no fix
(when position is lost)
JMODE,SBASR
Enable/disable SBAS ranging
JMODE,TIMEKEEP
Enable/disable continuous time updating in NMEA 0183 messages when there is no fix
(when position is lost)
JMODE,TUNNEL
Enable/disable faster reacquisition after coming out of a tunnel or query the current
setting
JPOS
Speed up the initial acquisition when changing continents with the receiver or query the
receiver for the current position of the receiver
JQUERY,GUIDE
Query the receiver for its determination on whether or not it is providing suitable
accuracy after both the SBAS and GPS have been acquired (up to five minutes)
JRELAY
Send user-defined text out of a serial port
JRESET
Reset the receiver to its default operating parameters by turning off outputs on all ports,
saving the configuration, and setting the configuration to its defaults
JSAVE
Send this command after making changes to the operating mode of the receiver
JSHOW
Query the current operating configuration of the receiver
JT
Query the receiver for its GPS engine type
Note: Use the JSAVE command to save changes you need to keep and wait for the $>SAVE COMPLETE response.
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Commands and Messages
GPS Commands
The following table lists the commands supported by the internal GPS engine for its configuration and operation.
Command
Description
JAGE
Specify maximum DGPS (COAST) correction age (6 to 8100 seconds)
JASC,GP
Enable the GPS data messages at a particular update rate to be turned on or off
JMASK
Specify the elevation cutoff mask angle for the GPS engine
JNP
Specify the number of decimal places output in the GPGGA and GPGLL messages
JOFF
Turn off all data messages being output through the current port or other port
JOFF,ALL
Turn off all data messages being output through all ports
JSMOOTH
Set the carrier smoothing interval (15 to 6000 seconds) or query the current setting
JTAU,COG
Set the course over ground (COG) time constant (0.00 to 3600.00 seconds) or query the current setting
JTAU,SPEED
Set the speed time constant (0.00 to 3600.00 seconds) or query the current setting
Note: Use the JSAVE command to save changes you need to keep and wait for the $>SAVE COMPLETE response.
SBAS Commands
The following table lists the commands supported by the SBAS demodulator for its control and operation.
Command
Description
JASC,D1
Set the RD1 diagnostic information message from the receiver to on or off
JASC,RTCM
Configure the receiver to output RTCM version 2 DGPS corrections from SBAS or beacon through
either receiver serial port
JGEO
Display information related to the current frequency of SBAS and its location in relation to the receiver’s
antenna
JWAASPRN
Change the SBAS PRNs in memory or query the receiver for current PRNs in memory
Note: Use the JSAVE command to save changes you need to keep and wait for the $>SAVE COMPLETE response.
e-Dif Commands
The following table lists the commands supported by the e-Dif application for its control and operation.
Command
Description
JRAD,1
Display the current reference position in e-Dif applications only
JRAD,1,LAT,LON,HEIGHT
Use this command—a derivative of the JRAD,1,P command—when absolute positioning is
required in e-Dif applications only
JRAD,1,P
e-Dif: Record the current position as the reference with which to compute e-Dif corrections.
This would be used in relative mode as no absolute point information is specified.
DGPS Base Station: Record the current position as the reference with which to compute
Base Station corrections in e-Dif applications only. This would be used in relative mode as
no absolute point information is specified
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Command
Description
JRAD,2
Forces the receiver to use the new reference point (you normally use this command
following a JRAD,1 type command)
JRAD,3
Invoke the e-Dif function once the unit has started up with the e-Dif application active, or,
update the e-Dif solution (calibration) using the current position as opposed to the
reference position used by the JRAD,2 command
JRAD,7
Turn auto recalibration on or off
Note: Use the JSAVE command to save changes you need to keep and wait for the $>SAVE COMPLETE response.
Crescent Vector Commands and Messages
The following table lists the commands related to the GPS heading aspect of the Crescent Vector OEM heading system.
Command
Description
JASC
Turn on different messages
JATT,COGTAU
Set the course over ground (COG) time constant (0.0 to 3600.0 seconds) or query the current
setting
JATT,CSEP
Query for the current separation between GPS antennas
JATT,EXACT
Enable/disable internal filter reliance on the entered antenna separation or query the current setting
JATT,FLIPBRD
Turn the flip feature on/off (allowing you to install the Crescent Vector board upside down) or query
the current feature status
JATT,GYROAID
Turn gyro aiding on or off or query the current setting
JATT,HBIAS
Set the heading bias or query the current setting
JATT,HELP
Show the available commands for GPS heading operation and status
JATT,HIGHMP
Set/query the high multipath setting for use in poor GPS environments
JATT,HRTAU
Set the heading rate time constant or query the current setting
JATT,HTAU
Set the heading time constant or query the current setting
JATT,LEVEL
Turn level operation on or off or query the current setting
JATT,MSEP
Manually set the GPS antenna separation or query the current setting
JATT,NEGTILT
Turn the negative tilt feature on or off or query the current setting
JATT,NMEAHE
Instruct the Crescent Vector to preface the HDG, HDM, HDT, and ROT messages with GP or HE
JATT,PBIAS
Set the pitch/roll bias or query the current setting
JATT,PTAU
Set the pitch time constant or query the current setting
JATT,ROLL
Configure the Crescent Vector for roll or pitch GPS antenna orientation
JATT,SEARCH
Force the Crescent Vector to reject the current GPS heading solution and begin a new search
JATT,SPDTAU
Set the speed time constant (0.0 to 3600.0 seconds) or query the current setting
JATT,SUMMARY
Display a summary of the current Crescent Vector settings
JATT,TILTAID
Turn tilt aiding on or off or query the current setting
JATT,TILTCAL
Calibrate tilt aiding or query the current feature status
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Commands and Messages
The following table lists Crescent Vector messages.
Message
Description
GPDTM
Datum reference
GPGGA
GPS fix data
GPGLL
Geographic position - latitude/longitude
GPGNS
GNSS fix data
GPGRS
GNSS range residuals
GPGSA
GNSS DOP and active satellites
GPGST
GNSS pseudorange error statistics
GPGSV
GNSS satellite in view
GPHDG/HEHDG
Provide magnetic deviation and variation for calculating magnetic or true heading
GPHDM/HEHDM
Provide magnetic heading of the vessel derived from the true heading calculated
GPHDT/HEHDT
Provide true heading of the vessel
GPHEV
Heave value in meters
GPRMC
Recommended minimum specific GNSS data
GPROT/HEROT
Contains the vessel’s rate of turn (ROT) information
GPRRE
Range residual message
GPVTG
Course over ground and ground speed
GPZDA
Time and date
PASHR
Time, heading, roll, and pitch data in one message
PSAT,GBS
Satellite fault detection used for RAIM
PSAT,HPR
Proprietary NMEA sentence that provides the heading, pitch/roll information and time in a single
message
PSAT,INTLT
Proprietary NMEA sentence that provides the title measurement from the internal inclinometer (in
degrees)
TSS1
Heading, pitch, roll, and heave message in the commonly used TSS1 message format
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GLONASS Commands and Messages
The following table lists the commands applicable to GLONASS-capable receivers.
Command
Description
JASC,GL
Enable the GLONASS data messages at a particular update rate to be turned on or off. When
turning messages on, various update rates are available depending on the requirements.
JMODE,GPSONLY
Set the receiver to use GPS data in the solution or query the current setting (if GLONASS is
available, setting to YES will cause the receiver to only use GPS data)
JNMEA,GGAALLGNSS
Configure the GGA string to include full GNSS information (the number of used GLONASS
satellites will be included in the GPGGA message) or query the current setting
The following table lists the messages applicable to GLONASS-capable receivers.
Message
Description
Bin62
GLONASS almanac information
Bin65
GLONASS ephemeris information
Bin66
GLONASS L1 code and carrier phase information
Bin69
GLONASS L1 diagnostic information
GLMLA
GLONASS almanac data - contains complete almanac data for one GLONASS satellite (multiple sentences
may be transmitted, one for each satellite in the GLONASS constellation)
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Commands and Messages
DGPS Base Station Commands
The following table lists the commands supported by the base station feature for its control and operation.
Command
Description
JRAD,1
Display the current reference position in e-Dif applications only
JRAD,1,LAT,LON,HEIGHT
Use this command—a derivative of the JRAD,1,P command—when absolute positioning is
required in e-Dif applications only
JRAD,1,P
e-Dif: Record the current position as the reference with which to compute e-Dif corrections.
This would be used in relative mode as no absolute point information is specified.
DGPS Base Station: Record the current position as the reference with which to compute
Base Station corrections in e-Dif applications only. This would be used in relative mode as
no absolute point information is specified
JRAD,9,1,1
Initialize the Base Station feature and use the previously entered point, either with
$JRAD,1,P or $JRAD,1,LAT,LON,HEIGHT, as the reference with which to compute Base
Station corrections in e-Dif applications only. Use this for both relative mode and absolute
mode.
Local Differential and RTK Commands and Messages
The following table lists the commands supported by Local Differential (L-Dif) and RTK feature for its control and operation.
Command
Description
JASC,CMR
Set the proprietary CMR messages to on or off to provide corrections to the rover (only
applies to an Eclipse base station receiver when using GPS dual frequency RTK mode)
JASC,DFX
Set the proprietary DFX messages to on or off to provide corrections to the rover (only
applies to a Crescent base receiver when using L-Dif or RTK mode)
JASC,ROX
Set the proprietary ROX messages to on or off to provide corrections to the rover (only
applies to an Eclipse base station receiver when using GPS dual frequency RTK mode)
JASC,RTCM3
Set the RTCM version 3 messages to on or off to provide corrections to the rover (only
applies to an Eclipse base station receiver when using GPS dual frequency RTK mode)
JASC,PSAT,RTKSTAT
Configure the receiver to output the most relevant parameters affecting RTK
JQUERY,RTKSTAT
Perform a one-time query of the most relevant parameters that affect RTK
JRTK,1
Show the receiver’s reference position (can issue command to base station or rover)
JRTK,1,LAT,LON,HEIGHT
Set the receiver’s reference position to the coordinates you enter (can issue command to
base station or rover)
JRTK,1,P
Set the receiver’s reference coordinates to the current calculated position if you do not
have known coordinates for your antenna location (can issue command to base station or
rover)
JRTK,5
Show the base station’s transmission status for RTK applications (can issue command to
base station)
JRTK,5,Transmit
Suspend or resume the transmission of RTK (can issue command to base station)
JRTK,6
Display the progress of the base station (can issue command to base station)
JRTK,12
Disable or enable the receiver to go into fixed integer mode (RTK) vs. float mode (L-Dif) can issue command to rover
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Command
Description
JRTK,17
Display the transmitted latitude, longitude, and height of the base station (can issue
command to base station or rover)
JRTK,18
Display the distance from the rover to the base station, in meters (can issue command to
rover)
JRTK,28
Set the base station ID transmitted in ROX/DFX/CMR/RTCM3 messages (can issue
command to base station)
The following table lists the Local Differential (L-Dif) and RTK messages.
Message
Description
PSAT,RTKSTAT
Contains the most relevant parameters affecting RTK
Beacon Receiver Commands and Messages
If integrating a Hemisphere GPS SBX beacon module with the receiver GPS engine, Hemisphere GPS recommends
interfacing the beacon receiver to Port D of the receiver engine. Hemisphere GPS has implemented some command and
message pass-through intelligence for such an integration. In this configuration you can issue the commands in the following
table to the beacon receiver through either Port A, Port B, or Port C of the receiver.
The following table lists the beacon receiver commands found in this Help file.
Command
Description
GPMSK
Tune beacon the receiver and turn on diagnostic information
PCSI,1,1
Obtain beacon status information from the SBX beacon engine inside the receiver
PCSI,3,2
Display the ten closest beacon stations
PCSI,3,3
Display the contents of the beacon station database
The following table lists the beacon receiver messages found in this Help file.
Message
Description
CRMSK
Operational status message of SBX
CRMSS
Performance status message of SBX
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Commands and Messages
NMEA 0183 SBX Queries
The following table lists the standard and Hemisphere GPS proprietary NMEA 0183 queries accepted by the SBX.
When you issue these queries to the SBX primary communications port, the response messages are output interspersed with
RTCM correction information. This may cause conflicts with a GPS receiver’s ability to compute differential corrected solutions.
By sending these queries to the SBX secondary communications port the flow of RTCM corrections on the primary port will not
be interrupted.
Query
NMEA 0183 Query
Type
Description
GPCRQ,MSK
Standard
Query the SBX for its operational status
GPCRQ,MSS
Standard
Query the SBX for its performance status
PCSI,0
Hemisphere GPS
proprietary
Query the SBX to output a list of available proprietary PCSI commands
PCSI,1
Hemisphere GPS
proprietary
Query the SBX for a selection of parameters related to the operational
status of its primary channel
PCSI,2
Hemisphere GPS
proprietary
Query the SBX to output a selection of parameters related to the operational
status of its secondary channel
PCSI,3,1
Hemisphere GPS
proprietary
Query the SBX to output the search information used for beacon selection in
Automatic Beacon Search mode. The output has three frequencies per line.
OmniSTAR Commands
The following tables lists the commands accepted by the LX-1 OmniSTAR receiver to configure and monitor the OmniSTAR
functionality of the receiver.
Command
Description
JBOOT,OMNI
Power down the OmniSTAR portion of the Eclipse engine and power it back up
JFREQ
Tune the OmniSTAR receiver (manually or automatically) or query the receiver for
the current setting
JHP,LIMIT
Specify the OmniSTAR HP/XP convergence threshold (range is 0.0 to 1.0 m) or
display the threshold as compared to the RMS value in the GPGST message
JHP,MODE,AUTOSEED
Enable or disable the AUTOSEED feature when operating in LBAND mode and
using OmniSTAR XP/HP service, or query the current setting
JHP,MODE,IGNORECONVEREGE
If using the JHP,LIMIT command to specify the OmniSTAR HP/XP convergence
threshold, use this command to set the receiver to ignore when the OmniSTAR
engine indicates it is converged or query the current setting
JHP,POS
Query the receiver for the stored position with standard deviations (StDevs) to be
used with the JHP,SEED command
JHP,POS,LAT,LON,HGT
Save lat, lon, hgt and optionally save corresponding standard deviations into nonvolatile memory, to be used with the JHP,SEED command
JHP,POS,LAT,LON,HGT,,,,OTHER
(For use with AUTOSEED feature) Save lat, lon, hgt and optionally save
corresponding standard deviations into non-volatile memory, to be used with the
JHP,MODE,AUTOSEED command
JHP,POS,OTHER
(For use with AUTOSEED feature) Query the receiver for the stored position with
standard deviations (StDevs) to be used with the JHP,MODE,AUTOSEED
command
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Command
Description
JHP,POS,PRESENT
Save the current location (lat, lon, height) and standard deviations into non-volatile
memory (provided the sum of the location standard deviations (StDev) < 0.6 m) to
be used with the JHP,SEED command
JHP,RESET,ACCURACY
Reset the HP convergence by forcing the solution to the current location but with
very large standard deviations
JHP,RESET,ENGINE
Reset the HP engine, forcing the solution to converge (this will also force an
AUTOSEED location to reconverge)
JHP,SEED
Initialize the OmniSTAR HP algorithm with the saved position and saved standard
deviations
JHP,SEED,LAT,LON,HGT
Initialize the OmniSTAR HP algorithm with the given coordinates and optional
standard deviations (this command has the combined effect of the
JHP,POS,LAT,LON,HGT and JHP,SEED commands)
JHP,STATIC
Place the OmniSTAR HP engine into or out of static mode, or query the current
setting
JHP,STATUS,AUTOSEED
Displays the status of the AUTOSEED initialization progress
JLBEAM
Display the information of each spot beam currently in use by the OmniSTAR
receiver
JLXBEAM
Display spot beam debug information
JOMS
Request the raw OmniSTAR subscription information
Note: Use the JSAVE command to save changes you need to keep and wait for the $J>SAVE COMPLETE response.
OmniSTAR HP
For Eclipse receivers you can reduce OmniSTAR HP initialization time by supplying the known position. If you know the
current position coordinates accurately, the OmniSTAR algorithm can be sent with the known coordinates.
Warning! The coordinates should be known to within 2 cm (1 in) before attempting to seed the position. Any errors entered
here will effect the future accuracy of the position solution.
You can query and store the current position with the following commands:
•
$JHP,POS,PRESENT
Save the current location and standard deviations of location into memory. If the current latitude, longitude, and
altitude standard deviations are cumulatively greater than 0.6 m, the current position is not stable and the command
is ignored. Under this condition, the system responds with the following message:
Present Location Not Stable
•
$JHP,POS
Query the receiver for the saved position and saved standard deviation
•
$JHP,POS,LAT,LON,HEIGHT
Save the longitude, and height and optionally save related standard deviations (LatStDev,LonStDev,HgtStDev) where
LAT and LON are in degrees and HEIGHT is in meters
To speed up initialization, you can seed the OmniSTAR algorithm with a position with the following command:
•
$JHP,SEED,LAT,LON,HEIGHT
Where LAT and LON are in degrees and HEIGHT is in meters. When the current receiver position is greater than 12
m (in the horizontal plane) from the seed position, the receiver responds with the following message and aborts the
command:
Current Position Too Far From Seed
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Commands and Messages
RAIM Commands
RAIM (Receiver Autonomous Integrity Monitoring) is a GPS integrity monitoring scheme that uses redundant ranging signals
to detect a satellite malfunction resulting in a large range error. The Hemisphere GPS products use RAIM to alert users when
errors have exceeded a user-specified tolerance. RAIM is available for SBAS, Beacon, and OmniSTAR applications.
The following table lists the available RAIM commands.
Command
Description
JRAIM
Specify the parameters of the RAIM scheme that affect the output of the PSAT,GBS message or query
the current setting
Data Messages
Note: 20 Hz output is only available with a 20 Hz subscription.
Message
Maximum
Rate
Description
GPALM
1 Hz
GPS almanac data
GPDTM
1 Hz
Datum reference
GPGGA
20 Hz
Detailed GPS position information
GPGLL
20 Hz
Latitude and longitude data
GPGNS
20 Hz
Fixes data for single or combined satellite navigation systems
GPGRS
20 Hz
Supports Receiver Autonomous Integrity Monitoring (RAIM)
GPGSA
1 Hz
GPS DOP and active satellite information
GPGST
1 Hz
GNSS pseudorange error statistics
GPGSV
1 Hz
GNSS satellite in view
GPHDG/HEHDG
20 Hz
Magnetic deviation and variation for calculating magnetic or true heading
GPHDM/HEHDM
20 Hz
Magnetic heading of the vessel derived from the true heading calculated
GPHDT/HEHDT
20 Hz
True heading of the vessel
GPHEV
20 Hz
Heave value in meters
GPRMC
20 Hz
Recommended minimum specific GNSS data
GPROT/HEROT
20 Hz
Vessel’s rate of turn (ROT) information
GPRRE
1 Hz
Range residual message
GPVTG
20 Hz
Course over ground and ground speed
GPZDA
20 Hz
UTC time and date information
PSAT,GBS
1 Hz
Used to support Receiver Autonomous Integrity Monitoring (RAIM)
PSAT,HPR
20 Hz
Proprietary NMEA message that provides the heading, pitch, roll, and time in a single
message
PSAT,INTLT
1 Hz
Proprietary NMEA message that provides the tilt measurements from the internal
inclinometers (in degrees)
RD1
1 Hz
SBAS diagnostic information
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Binary Messages
Message Structure
The binary messages supported by the receiver are in an Intel Little Endian format for direct read in a PC environment. More
information on this format at the following web site:
http://www.cs.umass.edu/~verts/cs32/endian.html
Each binary message begins with an 8-byte header and ends with a carriage return, line feed pair (0x0D, 0x0A). The first four
characters of the header is the ASCII sequence $BIN.
The following table provides the general binary message structure.
Component
Description
Type
Bytes
Values
Header
Synchronization String
4 byte string
4
$BIN
Block ID - type of binary message
Unsigned
short
2
1, 2, 80, 93, 94, 95, 96, 97,
98, or 99
DataLength - the length of the binary
messages
Unsigned
short
2
52, 16, 40, 56, 96, 128,
300, 28, 68, or 304
Data
Binary Data - varying fields of data
with a total length of DataLength bytes
Mixed fields
52, 16, 40, 56,
96, 128, 300,
28, 68, or 304
Varies - see message
tables
Epilogue
Checksum - sum of all bytes of the
data (all DataLength bytes); the sum
is placed in a 2-byte integer
Unsigned
short
2
Sum of data bytes
CR- Carriage return
Byte
1
0D hex
LF - Line feed
Byte
1
0A hex
Messages
Message
Description
Bin1
GPS position message (position and velocity data)
Bin2
GPS DOPs (Dilution of Precision)
Bin62
GLONASS almanac information
Bin65
GLONASS ephemeris information
Bin66
GLONASS L1 code and carrier phase information
Bin69
GLONASS L1 diagnostic information
Bin76
GPS L1/L2 code and carrier phase information
Bin80
SBAS data frame information
Bin89
SBAS satellite tracking information
Bin93
SBAS ephemeris information
Bin94
Ionospheric and UTC conversion parameters
Bin95
GPS ephemeris information
Bin96
GPS L1 code and carrier phase information
Bin97
Processor statistics
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Commands and Messages
Message
Description
Bin98
Satellite and almanac information
Bin99
GPS L1 diagnostic information
NMEA 2000 CAN Messages
Message
Description
GNSSPositionData
Detailed GPS position information
GNSSPositionRapidUpdates
Abbreviated GPS position information
NMEACogSogData
GPS speed and direction information
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Commands (All)
GPCRQ,MSK Command
Command
Type
NMEA 0183 SBX
Description
Standard NMEA 0183 query to prompt the SBX for its operational status (response is the CRMSK
message)
You can issue this command through the secondary serial port with a standard response issued to the
same port. This will not affect the output of RTCM data from the main serial port when the receiver has
acquired a lock on a beacon station.
Command
Format
$GPCRQ,MSK<CR><LF>
Receiver
Response
$CRMSK,fff.f,X,ddd,Y,n*CC<CR><LF>
where
Example
Response
Component
Description
fff.f
Frequency in kHz (283.5 to 325)
X
Tune mode (M = manual, A = automatic, D = database)
ddd
MSK bit rate (100 or 200 bps)
Y
MSK rate selection mode (M = manual, A = automatic, D = database)
n
Period of output of CRMSS performance status message (0 to 100 seconds)
Response example:
$CRMSK,322.0,M,100,A,2*CC
The frequency is 322.0 kHz, tune mode is Manual, MSK bit rate is 100 bps, MSK rate selection mode is
Automatic, and the message is output every 2 seconds.
Additional
Information
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Commands and Messages
GPCRQ,MSS Command
Command
Type
NMEA 0183 SBX
Description
Standard NMEA 0183 query to prompt the SBX for its performance status (response is the CRMSS
message)
You can issue this command through the secondary serial port with a standard response issued to the
same port. This will not affect the output of RTCM data from the main serial port when the receiver has
acquired a lock on a beacon station.
Command
Format
$GPCRQ,MSS<CR><LF>
Receiver
Response
$CRMSS,xx,yy,fff.f,ddd*CC<CR><LF>
where
Example
Response
Component
Description
xx
Signal strength in dBμV/m
yy
Signal-to-noise ratio (SNR) in dB
fff.f
Frequency in kHz (283.5 to 325)
ddd
MSK bit rate in bps (100 or 200)
Response example:
$CRMSS,65,36,322.0,100*CC
The signal strength is 65 dBμV/m, SNR is 36 dB, frequency is 322.0 kHz, and MSK bit rate is 100 bps.
Additional
Information
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GPMSK Command
Command
Type
Beacon Receiver
Description
Beacon Tune command
Instruct the SBX to tune to a specified frequency and automatically select the correct MSK rate. When you
send this command through Port A, Port B, or Port C, it is automatically routed to Port D. The resulting
confirmation of this message is returned to the same port from which you sent the command.
Command
Format
$GPMSK,fff.f,F,mmm,M[,n]<CR><LF>
where:
Command/Response
Component
Description
fff.f
Beacon frequency in kHz (283.5 to 325)
This may be left blank if the following field 'F' is set to 'A' (automatic) or 'D'
(database)
F
Frequency selection mode
(M = manual, A = automatic, D = database)
mmm
MSK bit rate
This may be left blank if the following field 'M' is set to 'A' (automatic) or 'D'
(database)
M
MSK rate selection mode
(M = manual, A = automatic, D = database)
n
Period of output of CRMSS performance status message (0 to 100 seconds),
where leaving the field blank will output the message once
Note: This field is optional when using database tuning mode or automatic
tuning mode.
Receiver
Response
$CRMSS,xx,yy,fff.f,ddd*CC<CR><LF>
where
82
Response
Component
Description
xx
Signal strength in dBμV/m
yy
Signal-to-noise ratio (SNR) in dB
fff.f
Frequency in kHz (283.5 to 325)
ddd
MSK bit rate in bps (100 or 200)
Commands and Messages
Example
To instruct the SBX to tune to 310.5 kHz with a bit rate of 100 and output the CRMSS message every 20
seconds issue the following command:
$GPMSK,310.5,M,100,M,20<CR><LF>
...and the receiver response is:
$CRMSS,65,36,310.5,100*CC
(repeating every n=20 seconds)
If using database tuning mode issue the following command:
$GPMSK,,D,,D<CR><LF>
If using automatic tuning mode issue the following command:
$GPMSK,,A,,A<CR><LF>
Additional
Information
When the SBX acknowledges this message, it immediately tunes to the specified frequency and
demodulates at the specified rate.
When you set 'n' to a non-zero value, the SBX outputs the CRMSS message at that period through the
serial port from which the SBX was tuned. When you issue this command with a non-zero 'n' value through
Port B, the periodic output of the CRMSS performance status message does not impact the output of
RTCM on Port A. However, when tuning the SBX with a non-zero 'n' value through Port A, the CRMSS
message is interspersed with the RTCM data. Most GPS engines will not be able to filter the CRMSS
message, causing the overall data to fail parity checking. When power to the SBX is removed and
reapplied, the status output interval resets to zero (no output).
When tuning the SBX engine, if the 'n' field in this message is non-zero, the CRMSS message output by
the SBX may interrupt the flow of RTCM data to the GPS receiver. Repower the SBX to stop the output of
the CRMSS message or retune the Beacon receiver with 'n' set to zero.
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JAGE Command
Command
Type
GPS
Description
Specify maximum DGPS (COAST) correction age (6 to 8100 seconds). Using COAST technology, the
receiver can use old correction data for extended periods of time.
The default setting for the receiver is 2700 seconds.
If you select a maximum correction age older than 1800 seconds (30 minutes), test the receiver to ensure
the new setting meets the requirements, as accuracy will slowly drift with increasing time.
Command
Format
$JAGE,AGE<CR><LF>
where 'AGE' is the maximum differential age timeout
Receiver
Response
$>
Example
To set the DGPS correction age to 60 seconds issue the following command:
$JAGE,60<CR><LF>
Additional
Information
84
To query the receiver for the current DGPS correction age, issue the JSHOW command.
What does <CR><LF> mean?
Commands and Messages
JAIR Command
Command
Type
General Operation and Configuration
Description
Specify how the receiver will respond to the dynamics associated with airborne applications or query the
current setting
Command
Format
Specify how the receiver responds
$JAIR,R<CR><LF>
where 'R' is the AIR mode:
•
NORM - normal track and nav filter bandwidth
•
HIGH - highest track and nav filter bandwidth (receiver is optimized for the high dynamic
environment associated with airborne platforms)
•
LOW - lowest track and nav filter bandwidth
•
AUTO - default track and nav filter bandwidth, similar to NORM but automatically goes to HIGH
above 30 m/sec
Query the current setting
$JAIR<CR><LF>
Receiver
Response
Receiver response when specifying how the receiver responds or querying the current setting
$>JAIR,MAN,NORM
$>JAIR,MAN,HIGH
$>JAIR,MAN,LOW
$>JAIR,AUTO,NORM
Example
To set the AIR mode to LOW issue the following command:
$JAIR,LOW<CR><LF>
The response is then:
$>JAIR,MAN,LOW<CR><LF>
Additional
Information
Defaults to normal (NORM) which is recommended for most applications. The AUTO option enables the
receiver to decide when to turn JAIR to HIGH.
CAUTION: Setting AIR mode to HIGH is not recommended for Crescent Vector operation.
On the HIGH setting, the receiver tolerates larger and sudden drops in the SNR value before it discards the
data as being invalid. This additional tolerance is beneficial in applications such as crop dusting where an
aircraft is banking rapidly. As the aircraft banks, the antenna position shifts from upright and having a clear
view of the sky to being tipped slightly, with a possibly obscured view of the sky, and then back to upright.
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This sudden tipping of the antenna causes the SNR value to drop.
If the tolerance is not set as HIGH, the receiver views the data recorded while banking as invalid and
discards it. As a result the GPS position will not be accurate.
The status of this command is also output in the JSHOW message.
86
Commands and Messages
JALT Command
Command
Type
General Operation and Configuration
Description
Turn altitude aiding for the receiver on or off
When set to something other than NEVER, altitude aiding uses a fixed altitude instead of using one
satellite’s observations to calculate the altitude. The advantage of this feature, when operating in an
application where a fixed altitude is acceptable, is that the extra satellite’s observations can be used to the
betterment of the latitude, longitude, and time offset calculations, resulting in improved accuracy and
integrity. Marine markets, for example, may be well suited for use of this feature.
Command
Format
$JALT,c[,h[,GEOID]]<CR><LF>
where 'c' (feature status variable) and 'h' (threshold variable) may be one of the following:
c Value
Description
Corresponding h Value
NEVER
Default mode of operation where altitude
aiding is not used
N/A
SOMETIMES
Sets the receiver to use altitude aiding
(depending upon the PDOP threshold)
specified by 'h'
See following Note
SATS
Sets the receiver to use altitude aiding
depending upon the number of visible
satellites. If there are fewer visible satellites
than specified by 'h', altitude aiding will be
used.
ALWAYS
Sets the receiver to use altitude aiding
regardless of a variable. In this case, the
ellipsoidal altitude 'h' that the receiver should
use may be specified.
To get an 'h' value to use with SOMETIMES and ALWAYS, using DGPS positions, average the height over
a period of time (the longer the time period, the more accurate this height value).
$JALT,ALWAYS,h<CR><LF>
In this command 'h' is the ellipsoid height.
If you use the height reported from the GPGGA message, because this is actually geoidal and not
ellipsoidal height, use:
$JALT,ALWAYS,h,GEOID<CR><LF>
Receiver
Response
$>
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Hemisphere GPS Technical Reference v1.02
Example
To turn altitude aiding on to SOMETIMES with an ellipsoidal height of 404.2 m issue the following
command:
$JALT,SOMETIMES,404.2<CR><LF>
To turn altitude aiding on to ALWAYS using the height of 401.6 m as reported in the GPGGA message
(geoidal height) issue the following command:
$JALT,ALWAYS,401.6,GEOID<CR><LF>
Additional
Information
To query the receiver for the current setting, issue the JSHOW command. For example, if you issue the
following command:
$JALT,SOMETIMES,404.2<CR><LF>
...then issuing the JSHOW command displays the following as part of its output:
$>JSHOW,ALT,SOMETIMES,404.2
88
Commands and Messages
JAPP Command
Command
Type
General Operation and Configuration
Description
Specify which of the installed applications should be utilized or query the receiver for the currently installed
applications
Note: Hemisphere GPS Crescent and Eclipse GPS receivers are able to hold up to two different
application firmware programs simultaneously.
Command
Format
Specify receiver application firmware (when two applications are present)
$JAPP,OTHER<CR><LF>
or
$JAPP,APP<CR><LF>
where 'APP' may be one of the following by name (depending on the underlined receiver type):
Crescent
•
WAAS – Changes to the SBAS application. For the sake of the application names, the SBAS
application is referred to as WAAS by the receiver’s internal firmware
•
AUTODIFF – Changes to the e-Dif application. Referred to as "AUTODIFF" in the receiver’s
internal firmware
•
LOCRTK – Changes to the local differential rover application
•
RTKBAS – Changes to the local differential base application
•
LBAND – Changes to OmniSTAR VBS
Eclipse
•
WAASRTKB – Changes to the SBAS/RTK Base application
•
OMNIHP – Changes to OmniSTAR XP/HP application
•
RTK – Changes to the RTK Rover application
Eclipse II
•
SBASRTKB – Changes to the SBAS/OmniSTAR/RTK Base application
•
AUTODIFF – Changes to the e-Dif application, referred to as "AUTODIFF" in the firmware
•
RTK – Changes to the RTK Rover application
miniEclipse
•
WAASRTKB – Changes to the SBAS/RTK Base application
•
AUTODIFF – Changes to the e-Dif application, referred to as "AUTODIFF" in the firmware
•
RTK – Changes to the RTK Rover application
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Query receiver application firmware
$JAPP<CR><LF>
Receiver
Response
For example, if WAAS (SBAS) and AUTODIFF (e-Dif) are the two installed applications (WAAS in slot1
and AUTODIFF in slot2) and WAAS is the current application, if you issue the
$JAPP,OTHER<CR><LF> command on a receiver, the response to $JAPP<CR><LF> will be
$>JAPP,AUTODIFF,WAAS,2,1, indicating that application slot 2 (e-Dif) is currently being used.
$JAPP command are the $JAPP,1<CR><LF> and
$JAPP,2<CR><LF> commands. You can use these to set the receiver to use the first or second
Other derivatives of the
application.
Hemisphere GPS recommends that you follow up the sending of these commands with a $JAPP query
to see which application is 1 or 2. It is best to use these two commands when upgrading the firmware
inside the receiver, because the firmware upgrading utility uses the application number to designate which
application to overwrite.
Response to querying the current setting
$>JAPP,CURRENT,OTHER,[1 OR 2],[2 OR 1]
where:
•
'CURRENT' indicates the current application in use
•
'OTHER' indicates the secondary application that is not currently in use
• 1 and 2 indicate which application slot is currently being used
For example, if the response to $JAPP<CR><LF> is $>JAPP,WAAS,AUTODIFF,1,2, it
indicates that:
Example
•
WAAS (SBAS) is in application slot 1
•
e-Dif is in application slot 2
•
WAAS in application slot 1 is currently being used
If WAASRTKB is the current application and OMNIHP is the other (second application) the response is
then:
$>JAPP,WAASRTKB,OMNIHP,1,2<CR><LF>
Additional
Information
90
Commands and Messages
JASC Command Overview
The JASC command is used to request ASCII messages.
Command
Description
JASC,CMR
Set the proprietary CMR messages to on or off to provide corrections to the rover
JASC,D1 (RD1)
Set the RD1 diagnostic information message from the receiver to on or off
JASC,DFX
Set the proprietary DFX messages to on or off to provide corrections to the rover
JASC,GL
Enable the GLONASS data messages at a particular update rate to be turned on or off. When
turning messages on, various update rates are available depending on the requirements.
JASC,GN
Enable the GNSS data messages at a particular update rate to be turned on or off. When
turning messages on, various update rates are available depending on the requirements.
JASC,GP
Enable the GPS data messages at a particular update rate to be turned on or off
JASC,INTLT
Configure the receiver to output pitch and roll data
JASC,PASHR
Configure the receiver to output time, heading, roll, and pitch data in one message
JASC,PSAT,RTKSTAT
Configure the receiver to output the most relevant parameters affecting RTK
JASC,PTSS1
Configure the receiver to output heading, pitch, roll, and heave in the commonly used TSS1
message format
JASC,ROX
Set the proprietary ROX messages to on or off to provide corrections to the rover
JASC,RTCM
Configure the receiver to output RTCM version 2 DGPS corrections from SBAS or beacon
through either receiver serial port
JASC,RTCM3
Set the RTCM version 3 messages to on or off to provide corrections to the rover
JASC,VIRTUAL
Configure the receiver to have RTCM data input on one port and output through the other
(when using an external correction source)
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Hemisphere GPS Technical Reference v1.02
JASC,CMR Command
Command
Type
Local Differential and RTK
Description
Set the proprietary CMR messages to on or off to provide corrections to the rover
This command only applies to an Eclipse base station receiver when using GPS dual frequency RTK
mode. RTK is relative to the reference position (base only).
Command
Format
$JASC,CMR,R[,OTHER]<CR><LF>
where:
•
'R' = correction status variable (0 = turn corrections Off, 1 = turn corrections On)
•
',OTHER' = optional field, enacts a change on the current port when you send the command
without it (and without the brackets) and enacts a change on the other port when you send the
command with it (without the brackets). See Configuring the Data Message Output for detailed
information on 'THIS' and 'OTHER' port terminology.
Receiver
Response
$>
Example
To turn on CMR messages on the OTHER port issue the following command:
$JASC,CMR,1,OTHER<CR><LF>
Additional
Information
92
To query the receiver for the current setting, issue the JSHOW command.
To change the broadcast station ID, use JRTK,28.
Commands and Messages
JASC,D1 Command
Command
Type
General Operation and Configuration, SBAS
Description
Set the RD1 diagnostic information message from the receiver to on or off
There is currently only an (R)D1 message.
Command
Format
$JASC,D1,R[,OTHER]<CR><LF>
where:
•
'R' = message rate (0 = Off, 1 = On at 1Hz)
•
',OTHER' = optional field, enacts a change in the RD1 message on the current port when you
send the command without it (and without the brackets) and enacts a change in the RD1
message on the other port when you send the command with it (without the brackets). See
Configuring the Data Message Output for detailed information on 'THIS' and 'OTHER' port
terminology.
Receiver
Response
$>
Example
To output the RD1 message once per second from THIS port issue the following command:
$JASC,D1,1<CR><LF>
...and the output will look similar to the following:
$RD1,410213,1052,1551.489,1,0,39,-611.5,0,1F,1F,0,999999
$RD1,410214,1052,1551.489,1,0,40,-615.1,0,1F,1F,0,999999
$RD1,410215,1052,1551.489,1,0,40,-607.1,0,1F,1F,0,999999
See RD1 message for a description of each field in the response.
Additional
Information
Although you request D1 through this command the responding message is RD1.
To query the receiver for the current setting, issue the JSHOW command. For example, if you issue the
following command:
$JASC,D1,1<CR><LF>
...then issuing the JSHOW command displays the following as part of its output:
$>JSHOW,ASC,D1,1
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JASC,DFX Command
Command
Type
Local Differential and RTK
Description
Set the proprietary DFX messages to on or off to provide corrections to the rover
This command only applies to a Crescent base receiver when using L-Dif or RTK mode. Differential is
relative to the reference position (base only). See the JASC,ROX command for the equivalent message
for the Eclipse series of products.
Command
Format
$JASC,DFX,R[,OTHER]<CR><LF>
where:
•
'R' = correction status variable (0 = turn corrections Off, 1 = turn corrections On)
•
',OTHER' = optional field, enacts a change on the current port when you send the command
without it (and without the brackets) and enacts a change on the other port when you send the
command with it (without the brackets). See Configuring the Data Message Output for detailed
information on 'THIS' and 'OTHER' port terminology.
Receiver
Response
$>
Example
To turn on DFX messages on THIS port issue the following command:
$JASC,DFX,1<CR><LF>
Additional
Information
94
To query the receiver for the current setting, issue the JSHOW command.
To change the broadcast station ID, use JRTK,28.
Commands and Messages
JASC,GL Command
Command
Type
GLONASS
Description
Enable the GLONASS data messages at a particular update rate to be turned on or off. When turning
messages on, various update rates are available depending on the requirements.
Command
Format
$JASC,MSG,R[,OTHER]<CR><LF>
where
•
'MSG' = name of the data message
•
'R' = message rate (see table below)
•
',OTHER' = optional field, enacts a change on the current port (THIS port) when you send the
command without it (and without the brackets) and enacts a change on the other port (OTHER
port) when you send the command with it (without the brackets). See Configuring the Data
Message Output for detailed information on 'THIS' and 'OTHER' port terminology.
Send a command with a zero value for the 'R' field to turn off a message.
MSG
R (rate in Hz)
Description
GLMLA
1 or 0
GLONASS almanac data
GLGGA
20, 10, 2, 1, 0 or .2
GPS fix data
GLGLL
20, 10, 2, 1, 0 or .2
Geographic position - latitude/longitude
GLGNS
20, 10, 2, 1, 0 or .2
GNSS fix data
GLGSA
1 or 0
GLONASS DOP and active satellites
GLGSV
1 or 0
GLONASS satellite in view
Receiver
Response
$>
Example
To output the GLGNS message through the OTHER port at a rate of 20 Hz, issue the following command:
$JASC,GLGNS,20,OTHER<CR><LF>
Additional
Information
The status of this command is also output in the JSHOW message.
What does <CR><LF> mean?
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JASC,GN Command
Command
Type
GPS, Crescent Vector
Description
Enable the GNSS data messages at a particular update rate to be turned on or off. When turning
messages on, various update rates are available depending on the requirements.
Command
Format
$JASC,MSG,R[,OTHER]<CR><LF>
where
•
'MSG' = name of the data message
•
'R' = message rate (see table below)
•
',OTHER' = optional field, enacts a change on the current port (THIS port) when you send the
command without it (and without the brackets) and enacts a change on the other port (OTHER
port) when you send the command with it (without the brackets). See Configuring the Data
Message Output for detailed information on 'THIS' and 'OTHER' port terminology.
Send a command with a zero value for the 'R' field to turn off a message.
MSG
R (rate in Hz)
Description
GPGGA
20, 10, 2, 1, 0 or .2
GPS fix data
GPGLL
20, 10, 2, 1, 0 or .2
Geographic position - latitude/longitude
GPGNS
20, 10, 2, 1, 0 or .2
GNSS fix data
GPGSA
1 or 0
GNSS DOP and active satellites
Receiver
Response
$>
Example
To output the GNGNS message through the OTHER port at a rate of 20 Hz, issue the following command:
$JASC,GNGNS,20,OTHER<CR><LF>
Additional
Information
96
The status of this command is also output in the JSHOW message.
What does <CR><LF> mean?
Commands and Messages
JASC,GP Command
Command
Type
GPS, Crescent Vector
Description
Enable the GPS data messages at a particular update rate to be turned on or off. When turning messages
on, various update rates are available depending on the requirements.
Command
Format
$JASC,MSG,R[,OTHER]<CR><LF>
where
•
'MSG' = name of the data message
•
'R' = message rate (see table below)
•
',OTHER' = optional field, enacts a change on the current port (THIS port) when you send the
command without it (and without the brackets) and enacts a change on the other port (OTHER
port) when you send the command with it (without the brackets). See Configuring the Data
Message Output for detailed information on 'THIS' and 'OTHER' port terminology.
Send a command with a zero value for the 'R' field to turn off a message.
MSG
R (rate in Hz)
Description
GPALM
1 or 0
GPS almanac data
GPDTM
1 or 0
Datum reference
GPGBS
1 or 0
Satellite fault detection used for RAIM
GPGGA
20, 10, 2, 1, 0 or .2
Detailed GPS position information
GPGLL
20, 10, 2, 1, 0 or .2
Latitude and longitude data
GPGNS
20, 10, 2, 1, 0 or .2
Fixes data for single or combined satellite navigation
systems
GPGRS
20, 10, 2, 1, 0 or .2
GNSS range residuals
GPGSA
1 or 0
GPS DOP and active satellite information
GPGST
1 or 0
GNSS pseudorange error statistics
GPGSV
1 or 0
GNSS satellite in view
GPHDG
or
HEHDG
20, 10, 2, 1, 0 or .2
Magnetic deviation and variation for calculating
magnetic or true heading
GPHDM
or
HEHDM
20, 10, 2, 1, 0 or .2
Magnetic heading of the vessel derived from the true
heading calculated
GPHDT
or
HEHDT
20, 10, 2, 1, 0 or .2
True heading of the vessel
GPHEV
20, 10, 2, 1, 0 or .2
Heave value in meters
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GPHPR
20, 10, 2, 1, 0 or .2
Proprietary NMEA message that provides the heading,
pitch, roll, and time in a single message
GPRMC
10, 2, 1, 0 or .2
Recommended minimum specific GNSS data
GPROT
or
HEROT
20, 10, 2, 1, 0 or .2
Vessel’s rate of turn (ROT) information
GPRRE
1 or 0
Range residual message
GPVTG
20, 10, 2, 1, 0 or .2
Course over ground and ground speed
GPZDA
20, 10, 2, 1, 0 or .2
UTC time and date information
INTLT
1 or 0
Proprietary NMEA message that provides the tilt
measurements from the internal inclinometers (in
degrees)
Receiver
Response
$>
Example
To output the GPGGA message through the OTHER port at a rate of 20 Hz, issue the following command:
$JASC,GPGGA,20,OTHER<CR><LF>
Additional
Information
98
The status of this command is also output in the JSHOW message.
What does <CR><LF> mean?
Commands and Messages
JASC,INTLT Command
Command
Type
Crescent Vector
Description
Configure the receiver to output pitch and roll data (pitch and roll are factory calibrated over temperature
to be accurate to ±3°C)
Command
Format
$JASC,INTLT,R[,OTHER]<CR><LF>
where
Receiver
Response
•
'R' = message rate (0 = Off, 1 = On at 1Hz)
•
',OTHER' = optional field, enacts a change on the current port when you send the command
without it (and without the brackets) and enacts a change on the other port when you send the
command with it (without the brackets). See Configuring the Data Message Output for detailed
information on 'THIS' and 'OTHER' port terminology.
$PSAT,INTLT,pitch,roll*CC<CR><LF>
where pitch and roll are in degrees
Example
Additional
Information
PSAT,INTLT message
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JASC,PASHR Command
Command
Type
Crescent Vector
Description
Configure the receiver to output time, heading, roll, and pitch data in one message
Command
Format
$JASC,PASHR,R[,OTHER]<CR><LF>
where
Receiver
Response
•
'R' = message rate (0 = Off, 1 = On at 1Hz)
•
',OTHER' = optional field, enacts a change on the current port when you send the command
without it (and without the brackets) and enacts a change on the other port when you send the
command with it (without the brackets). See Configuring the Data Message Output for detailed
information on 'THIS' and 'OTHER' port terminology.
$PASHR,hhmmss.ss,HHH.HH,T,RRR.RR,PPP.PP,heave,rr.rrr,pp.ppp,hh.hhh,QF*
CC<CR><LF>
where:
Message
Component
Description
hhmmss.ss
UTC time
HHH.HH
Heading value in decimal degrees
T
True heading (T displayed if heading is relative to true north)
RRR.RR
Roll in decimal degrees (- sign will be displayed when applicable)
PPP.PP
Pitch in decimal degrees (- sign will be displayed when applicable)
heave
Heave, in meters
rr.rrr
Roll standard deviation in decimal degrees
pp.ppp
Pitch standard deviation in decimal degrees
hh.hhh
Heading standard deviation in decimal degrees
QF
Quality Flag
•
•
•
100
0 = No position
1 = All non-RTK fixed integer positions
2 = RTK fixed integer position
*CC
Checksum
<CR>
Carriage return
<LF>
Line feed
Commands and Messages
Example
To turn on the PASHR message on THIS port issue the following command:
$JASC,PASHR,1<CR><LF>
...and the message output appears similar to the following:
$PASHR,162930.00,,T,2.48,3.92,-0.64,0.514,0.514,0.000,1*05
$PASHR,162931.00,,T,2.38,3.93,-0.70,0.508,0.508,0.000,1*07
$PASHR,162932.00,,T,2.67,4.00,-0.66,0.503,0.503,0.000,1*04
Additional
Information
PASHR message
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JASC,PSAT,RTKSTAT Command
Command
Type
Local Differential and RTK
Description
Configure the receiver to output the most relevant parameters affecting RTK
Command
Format
$JASC,PSAT,RTKSTAT,R[,OTHER]<CR><LF>
where:
•
'R' = message rate (0 = Off, 1 = On at 1Hz)
•
',OTHER' = optional field, enacts a change on the current port when you send the command
without it (and without the brackets) and enacts a change on the other port when you send the
command with it (without the brackets). See Configuring the Data Message Output for detailed
information on 'THIS' and 'OTHER' port terminology.
You can also perform a one-time query of the message information by issuing the JQUERY,RTKSTAT
command.
Receiver
Response
$>
Example
To turn on this message on the THIS port issue the following command:
$JASC,PSAT,RTKSTAT,1<CR><LF>
Additional
Information
102
To query the receiver for the current setting, issue the JSHOW command. See also PSAT,RTKSTAT
message.
Commands and Messages
JASC,PTSS1 Command
Command
Type
Crescent Vector
Description
Configure the receiver to output heading, pitch, roll, and heave in the commonly used TSS1 message
format
Command
Format
$JASC,PTSS1,R[,OTHER]<CR><LF>
where
Receiver
Response
•
'R' = message rate (in Hz) of 0 (off), 0.25, 0.5, 1, 2, 4, 5, 10, or 20 (if subscribed)
•
',OTHER' = optional field, enacts a change on the current port when you send the command
without it (and without the brackets) and enacts a change on the other port when you send the
command with it (without the brackets). See Configuring the Data Message Output for detailed
information on 'THIS' and 'OTHER' port terminology.
:XXAAAASMHHHHQMRRRRSMPPPP*CC<CR><LF>
where:
Messa
ge
Compo
nent
Description
XX
Horizontal acceleration
AAAA
Vertical acceleration
HHHH
Heave
S
S = space character
M
Space if positive; minus if negative
Q
Status flag
Value
Description
h
Heading aided mode (settling) The System is receiving heading aiding signals from a
gyrocompass but is still awaiting the end of the three minutes
settling period after power-on or a change of mode or heave
bandwidth. The gyrocompass may take several hours to settle
after it has been powered-on. During this time, gyrocompass
aiding of the System will not be perfect. The status flag does NOT
indicate this condition.
F
Full aided mode (settled condition) - The System is receiving and
using aiding signals from a gyrocompass and from a GPS receiver
or a Doppler log.
M
Space if positive; minus if negative
RRRR
Roll
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Additional
Information
104
S
S = space character
M
Space if positive; minus if negative
PPPP
Pitch
*CC
Checksum
<CR>
Carriage return
<LF>
Line feed
TSS1 message
Commands and Messages
JASC,ROX Command
Command
Type
Local Differential and RTK
Description
Set the proprietary ROX messages to on or off to provide corrections to the rover
This command only applies to an Eclipse base station receiver when using GPS dual frequency RTK
mode. RTK is relative to the reference position (base only).
Command
Format
$JASC,ROX,R[,OTHER]<CR><LF>
where:
•
'R' = correction status variable (0 = turn corrections Off, 1 = turn corrections On)
•
',OTHER' = optional field, enacts a change on the current port when you send the command
without it (and without the brackets) and enacts a change on the other port when you send the
command with it (without the brackets). See Configuring the Data Message Output for detailed
information on 'THIS' and 'OTHER' port terminology.
Receiver
Response
$>
Example
To turn on ROX messages on the OTHER port issue the following command:
$JASC,ROX,1,OTHER<CR><LF>
Additional
Information
To query the receiver for the current setting, issue the JSHOW command.
To change the broadcast station ID, use JRTK,28.
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Hemisphere GPS Technical Reference v1.02
JASC,RTCM Command
Command
Type
SBAS
Description
Configure the receiver to output RTCM version 2 DGPS corrections from SBAS or beacon through either
receiver serial port. The correction data output is RTCM SC-104, even though SBAS uses a different
over-the-air protocol (RTCA).
Command
Format
$JASC,RTCM,R[,OTHER]<CR><LF>
where:
•
'R' = message status variable (0 = Off, 1 = On)
•
',OTHER' = optional field, enacts a change on the current port when you send the command
without it (and without the brackets) and enacts a change on the other port when you send the
command with it (without the brackets). See Configuring the Data Message Output for detailed
information on 'THIS' and 'OTHER' port terminology.
Receiver
Response
$>
Example
To output RTCM corrections from SBAS or beacon on THIS port (current port) issue the following
command:
$JASC,RTCM,1<CR><LF>
Additional
Information
To verify the current setting is on, issue the JSHOW command. You will see output similar to the
following:
$>JSHOW,ASC,RTCM,1.0
If the current setting is off, the JSHOW command will not show any information for this setting.
106
Commands and Messages
JASC,RTCM3 Command
Command
Type
Local Differential and RTK
Description
Set the RTCM version 3 messages to on or off to provide corrections to the rover
This command only applies to an Eclipse base station receiver when using GPS dual frequency RTK
mode. RTK is relative to the reference position (base only).
Command
Format
$JASC,RTCM3,R[,OTHER]<CR><LF>
where:
•
'R' = correction status variable (0 = turn corrections Off, 1 = turn corrections On)
•
',OTHER' = optional field, enacts a change on the current port when you send the command
without it (and without the brackets) and enacts a change on the other port when you send the
command with it (without the brackets). See Configuring the Data Message Output for detailed
information on 'THIS' and 'OTHER' port terminology.
Receiver
Response
$>
Example
To turn on RTCM3 messages on the OTHER port issue the following command:
$JASC,RTCM3,1,OTHER<CR><LF>
Additional
Information
To query the receiver for the current setting, issue the JSHOW command.
To change the broadcast station ID, use JRTK,28.
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Hemisphere GPS Technical Reference v1.02
JASC,VIRTUAL Command
Command
Type
General Operation and Configuration
Description
Configure the receiver to have RTCM data input on one port and output through the other (when using an
external correction source)
For example, if RTCM is input on Port B, the data will be output through Port A having corrected the
receiver position. The receiver acts as a pass-through for the RTCM data. Either port may be configured
to accept RTCM data input; this command enables the opposite port to output the RTCM data.
Command
Format
$JASC,VIRTUAL,R[,OTHER]<CR><LF>
where:
•
'R' = message status variable (0 = Off, 1 = On)
•
',OTHER' = optional field, enacts a change on the current port when you send the command
without it (and without the brackets) and enacts a change on the other port when you send the
command with it (without the brackets). See Configuring the Data Message Output for detailed
information on 'THIS' and 'OTHER' port terminology.
Receiver
Response
$>
Example
To configure THIS port to output RTCM messages that are being input through the OTHER port issue the
following command:
$JASC,VIRTUAL,1
Additional
Information
108
Commands and Messages
JATT Command Overview
The JATT command is used to define or query attitude settings for Vector products.
Command
Description
JATT,COGTAU
Set the course over ground (COG) time constant (0.0 to 3600.0 seconds) or query the current
setting
JATT,CSEP
Query to retrieve the current separation between GPS antennas
JATT,EXACT
Enable/disable internal filter reliance on the entered antenna separation or query the current
setting
JATT,FLIPBRD
Allow upside down installation
JATT,GYROAID
Turn on gyro aiding or query the current feature status
JATT,HBIAS
Set the heading bias or query the current setting
JATT,HELP
Show the available commands for GPS heading operation and status
JATT,HIGHMP
Set/query the high multipath setting for use in poor GPS environments
JATT,HRTAU
Set the rate of turn time constant or query the current setting
JATT,HTAU
Set the heading time constant or query the current setting
JATT,LEVEL
Turn on level operation or query the current feature status
JATT,MSEP
Set (manually) the GPS antenna separation or query the current setting
JATT,NEGTILT
Turn on the negative tilt feature or query the current setting
JATT,NMEAHE
Instruct the Crescent Vector on how to preface the HDT and HDR messages
JATT,PBIAS
Set the pitch bias or query the current setting
JATT,PTAU
Set the pitch time constant or query the current setting
JATT,ROLL
Configure the Crescent Vector for roll or pitch output
JATT,SEARCH
Force a new RTK heading search
JATT,SPDTAU
Set the speed time constant (0.0 to 3600.0 seconds) or query the current setting
JATT,SUMMARY
Show the current configuration of the Crescent Vector
JATT,TILTAID
Turn tilt aiding on/off or query the Crescent Vector for the current status of this feature
JATT,TILTCAL
Calibrate the internal tilt sensor of the Crescent Vector
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Hemisphere GPS Technical Reference v1.02
JATT,CSEP Command
Command
Type
Crescent Vector
Description
Query the Crescent Vector for the current calculated separation between antennas, as solved for by the
attitude algorithms
Command
Format
$JATT,CSEP<CR><LF>
Receiver
Response
$>JATT,X,CSEP
where 'X' is the antenna separation in meters
Additional
Information
110
Commands and Messages
JATT,COGTAU Command
Note: The JTAU,COG command provides identical functionality but works with Crescent and Eclipse products in addition to
Crescent Vector products.
Command
Type
Crescent Vector
Description
Set the course over ground (COG) time constant (0.0 to 3600.0 seconds) or query the current setting
This command allows you to adjust the level of responsiveness of the COG measurement provided in the
GPVTG message. The default value is 0.0 seconds of smoothing. Increasing the COG time constant
increases the level of COG smoothing.
Command
Format
Set the COG time constant
$JATT,COGTAU,cogtau<CR><LF>
where "cogtau" is the new COG time constant that falls within the range of 0.0 to 200.0 seconds
The setting of this value depends upon the expected dynamics of the Crescent. If the Crescent will be in
a highly dynamic environment, this value should be set lower because the filtering window would be
shorter, resulting in a more responsive measurement. However, if the receiver will be in a largely static
environment, this value can be increased to reduce measurement noise.
Query the current setting
$JATT,COGTAU<CR><LF>
Receiver
Response
$>
Additional
Information
You can use the following formula to determine the COG time constant:
cogtau (in seconds) = 10 / maximum rate of change of course (in °/s)
If you are unsure about the best value for this setting, it is best to be conservative and leave it at the
default setting of 0.0 seconds.
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Hemisphere GPS Technical Reference v1.02
JATT,EXACT Command
Command
Type
Crescent Vector
Description
Enable/disable internal filter reliance on the entered antenna separation or query the current setting
Command
Format
Enable/disable internal filter reliance
To enable internal filter reliance:
$JATT,EXACT,YES<CR><LF>
To disable internal filter reliance:
$JATT,EXACT,NO<CR><LF>
Query the current setting
$JATT,EXACT<CR><LF>
Receiver
Response
Additional
Information
112
$>
Commands and Messages
JATT,FLIPBRD Command
Command
Type
Crescent Vector
Description
Turn the flip feature on/off or query the current feature status
Allow the Crescent Vector OEM board to be installed upside down. You should use this command only
with the Vector Sensor and the Crescent Vector OEM board because flipping the OEM board does not
affect the antenna array that needs to remain facing upwards. When using this command, the board
needs to be flipped about roll so the front still faces the front of the vessel.
Command
Format
Turn the flip feature on/off
To turn the flip feature on:
$JATT,FLIPBRD,YES<CR><LF>
To turn the flip feature off (return to default mode - right side up):
$JATT,FLIPBRD,NO<CR><LF>
Query current the current setting
$JATT,FLIPBRD<CR><LF>
Receiver
Response
$>
Additional
Information
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Hemisphere GPS Technical Reference v1.02
JATT,GYROAID Command
Command
Type
Crescent Vector
Description
Turn gyro aiding on or off or query the current setting
The Crescent Vector’s internal gyro—enabled by default when shipped—offers two benefits.
•
It shortens reacquisition times when a GPS heading is lost because of obstruction of satellite
signals. It does this by reducing the search volume required for solution of the RTK.
•
It provides an accurate substitute heading for a short period (depending on the roll and pitch of
the vessel) ideally seeing the system through to reacquisition.
For these two benefits, Hemisphere GPS highly recommend leaving gyro aiding on.
Exceeding rates of 90°/sec is not recommended because the gyro cannot measure rates beyond this
point. This is a new recommendation since Hemisphere GPS now uses gyro measurements to obtain a
heading rate measurement.
Command
Format
Turn gyro aiding on/off
To turn gyro aiding on:
$JATT,GYROAID,YES<CR><LF>
To turn gyro aiding off:
$JATT,GYROAID,NO<CR><LF>
Query the current setting
$JATT,GYROAID<CR><LF>
Receiver
Response
$>
Additional
Information
Every time you power up the Crescent Vector the gyro goes through a warmup procedure and calibrates
itself. You cannot save the resulting calibration, so the self-calibration takes place every time the
Crescent Vector is power cycled.
This self-calibration procedure takes several minutes and is the equivalent of the following manual
calibration procedure.
With the Crescent Vector unit installed:
1.
2.
Apply power and wait several minutes until it has acquired a GPS signal and is computing
heading.
Ensure gyroaiding is on by issuing the following command:
$JATT,GYROAID<CR><LF>
3.
4.
114
Slowly spin the unit for one minute at no more than 15°/sec.
Keep the unit stationary for four minutes. Both the manual and the self-calibration procedures
calibrate the Crescent Vector’s gyro to the same effect.
Commands and Messages
JATT,HBIAS Command
Command
Type
Crescent Vector
Description
Set the heading output from the Crescent Vector to calibrate the true heading of the antenna array to
reflect the true heading of the vessel or query the current setting
Command
Format
Set the heading output
$JATT,HBIAS,X<CR><LF>
where 'X' is a bias that will be added to the Crescent Vector’s heading in degrees. The acceptable range
for the heading bias is -180.0° to 180.0°. The default value of this feature is 0.0°.
Query the current setting (current compensation angle)
$JATT,HBIAS<CR><LF>
Receiver
Response
$>
Additional
Information
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Hemisphere GPS Technical Reference v1.02
JATT,HELP Command
Command
Type
Crescent Vector
Description
Show the available commands for GPS heading operation and status
Command
Format
$JATT,HELP<CR><LF>
Receiver
Response
$>JATT,HELP,CSEP,MSEP,EXACT,LEVEL,HTAU,HRTAU,HBIASPBIAS,NEGTILT,ROLL,
TILTAID,TILTCAL,MAGAID,MAGCAL,MAGCLR,GYROAID,COGTAU,SPDTAU,SEARCH,
SUMMARY
Additional
Information
116
Commands and Messages
JATT,HIGHMP Command
Command
Type
Crescent Vector
Description
Enable/disable the high multipath setting for use in poor GPS environments or query the current setting
Enabling HIGHMP mode may result in longer heading acquisition times in high multipath environments. In
HIGHMP mode, the Vector will not output heading until it has good confidence in the result. In very poor
environments, this may take a few minutes or more; in normal environments, there is only a slight
increase in heading acquisition time.
Command
Format
Set the high multipath setting
To enable the high multipath setting:
$JATT,HIGHMP,YES<CR><LF>
To disable the high multipath setting:
$JATT,HIGHMP,NO<CR><LF>
Query the current setting
$JATT,HIGHMP<CR><LF>
Receiver
Response
$>
Additional
Information
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Hemisphere GPS Technical Reference v1.02
JATT,HRTAU Command
Command
Type
Crescent Vector
Description
Set the heading rate time constant to adjust the level of responsiveness of the rate of heading change
measurement provided in the GPROT message or query the current setting
The default value of this constant is 2.0 seconds of smoothing. Increasing the time constant increases the
level of heading smoothing.
Command
Format
Set the heading rate time constant
$JATT,HRTAU,hrtau<CR><LF>
where 'hrtau' is the new time constant that falls within the range of 0.0 to 3600.0 seconds
The setting of this value depends upon the expected dynamics of the vessel. For example, if the vessel is
very large and cannot turn quickly, increasing this time is reasonable. The resulting heading would have
reduced ‘noise’, resulting in consistent values with time. However, artificially increasing this value such
that it does not agree with a more dynamic vessel could create a lag in the rate of heading change
measurement with higher rates of turn.
Query the current setting
$JATT,HRTAU<CR><LF>
Receiver
Response
$>
Additional
Information
You can use the following formula to determine the level of smoothing:
hrtau (in seconds) = 10 / maximum rate of the rate of turn (in °/s2)
Note: If you are unsure about the best value for the setting, leave it at the default setting of 2.0 seconds.
118
Commands and Messages
JATT,HTAU Command
Command
Type
Crescent Vector
Description
Set the heading time constant to adjust the level of responsiveness of the true heading measurement
provided in the GPHDT message or query the current setting
The default value of this constant is 2.0 seconds of smoothing when the gyro is enabled.
Although, the gyro is enabled by default, you can turn it off. When you turn the gyro off, the default value
of the heading time constant is 0.5 seconds of smoothing. Increasing the heading time constant increases
the level of heading smoothing.
Command
Format
Set the heading time constant
$JATT,HTAU,htau<CR><LF>
where 'htau' is the new time constant that falls within the range of 0.0 to 3600.0 seconds
The setting of this value depends upon the expected dynamics of the vessel. If the vessel is very large
and cannot turn quickly, increasing this time is reasonable. The resulting heading would have reduced
‘noise’ resulting in consistent values with time. However, artificially increasing this value such that it does
not agree with a more dynamic vessel could create a lag in the heading measurement with higher rates of
turn.
Query the current setting
$JATT,HTAU<CR><LF>
Receiver
Response
$>
Additional
Information
You can use the following formula to determine level of heading smoothing required when the gyro is in
use:
Gyro on
htau (in seconds) = 40 / maximum rate of turn (in °/s)
Gyro off
htau (in seconds) = 10 / maximum rate of turn (in °/s)
If you are unsure about the best value for the setting, leave it at the default setting of 2.0 seconds when
the gyro is on and at 0.5 seconds when the gyro is off.
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JATT,LEVEL Command
Command
Type
Crescent Vector
Description
Turn level operation on or off or query the current setting
Invoke the level operation mode of the Crescent Vector. If the application will not involve the system tilting
more than ±10°, you may use this mode of operation. The benefit of using level operation is increased
robustness and faster acquisition times of the RTK heading solution.
This feature is turned off by default.
Command
Format
Turn level operation on/off
To turn level operation on:
$JATT,LEVEL,YES<CR><LF>
To turn level operation off:
$JATT,LEVEL,NO<CR><LF>
Query the current setting
$JATT,LEVEL<CR><LF>
Receiver
Response
Additional
Information
120
$>
Commands and Messages
JATT,MSEP Command
Command
Type
Crescent Vector
Description
Manually enter a custom separation between antennas (must be accurate to within 1 to 2 cm) or query
the current setting
Command
Format
Set the antenna separation
Using the new center-to-center measurement, issue the following command:
$JATT,MSEP,sep<CR><LF>
where "sep" is the measured antenna separation entered in meters
Query the current setting
$JATT,MSEP<CR><LF>
Receiver
Response
$>
Additional
Information
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Hemisphere GPS Technical Reference v1.02
JATT,NEGTILT Command
Command
Type
Crescent Vector
Description
Turn the negative tilt feature on or off or query the current setting
When the secondary GPS antenna (SA) is below the primary GPS antenna (PA), there is an angle formed
between a horizontal line through the center of the primary antenna (Line A in the diagram below) and an
intersecting line through the center of the primary and secondary antennas (Line B). This angle is
considered to be negative.
Depending on the convention for positive and negative pitch/roll, you want to change the sign (either
positive or negative) of the pitch/roll.
Command
Format
Turn negative tilt feature on/off
To change the sign of the pitch/roll measurement:
$JATT,NEGTILT,YES<CR><LF>
To return the sign of the pitch/roll measurement to its original value:
$JATT,NEGTILT,NO<CR><LF>
Query the current setting
$JATT,NEGTILT<CR><LF>
Receiver
Response
Additional
Information
122
$>
Commands and Messages
JATT,NMEAHE Command
Command
Type
Crescent Vector
Description
Instruct the Crescent Vector to preface the following messages with GP or HE.
Command
Format
•
HDG
•
HDM
•
HDT
•
ROT
$JATT,NMEAHE,X<CR><LF>
where 'X' is either 1 for HE or 0 for GP
To preface specific messages with GP
$JATT,NMEAHE,0<CR><LF>
To preface specific messages with HE
$JATT,NMEAHE,1<CR><LF>
Receiver
Response
Additional
Information
$>JATT,NMEAHE,OK
The HDM message is for a magnetic compass. The message will be HCHDM when requesting with
$JATT,NMEAHE,1 specified.
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JATT,PBIAS Command
Command
Type
Crescent Vector
Description
Set the pitch/roll output from the Crescent Vector to calibrate the measurement if the antenna array is not
installed in a horizontal plane or query the current setting
Command
Format
Set the pitch/roll output
$JATT,PBIAS,X<CR><LF>
where "X" is a bias that will be added to the Crescent Vector’s pitch/roll measure, in degrees
The acceptable range for the pitch bias is -15.0° to 15.0°. The default value is 0.0°.
Query the current setting
$JATT,PBIAS<CR><LF>
Receiver
Response
$>
Additional
Information
Note: The pitch/roll bias is added after the negation of the pitch/roll measurement (if invoked with the
JATT,NEGTILT command).
124
Commands and Messages
JATT,PTAU Command
Command
Type
Crescent Vector
Description
Set the level of responsiveness of the pitch measurement provided in the PSAT,HPR message or query
the current setting
The default value of the pitch time constant is 0.5 seconds of smoothing. Increasing the pitch time
constant increases the level of pitch smoothing.
Command
Format
Set the pitch time constant
$JATT,PTAU,ptau<CR><LF>
where 'ptau' is the new time constant that falls within the range of 0.0 to 3600.0 seconds
The setting of this value depends upon the expected dynamics of the vessel. For instance, if the vessel is
very large and cannot pitch quickly, increasing this time is reasonable. The resulting pitch would have
reduced ‘noise’, resulting in consistent values with time. However, artificially increasing this value such
that it does not agree with a more dynamic vessel could create a lag in the pitch measurement.
Query the current setting
$JATT,PTAU<CR><LF>
Note: If you are unsure about the best value for the setting, leave it at the default setting of 0.5 seconds
Receiver
Response
$>
Additional
Information
You can use the following formula to determine the level of pitch smoothing required:
ptau (in seconds) = 10 / maximum rate of pitch (in °/s)
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JATT,ROLL Command
Command
Type
Crescent Vector
Description
Configure the Crescent Vector for roll or pitch GPS antenna orientation
Command
Format
Configure the Crescent Vector for pitch or roll GPS antenna orientation
To configure the Crescent Vector for roll GPS antenna orientation (the Antenna Array must be installed
perpendicular to the vessel’s axis):
$JATT,ROLL,YES<CR><LF>
To configure the Crescent Vector for pitch GPS antenna orientation (default):
$JATT,ROLL,NO<CR><LF>
Query the current setting
$JATT,ROLL<CR><LF>
Receiver
Response
Additional
Information
126
$>
Commands and Messages
JATT,SEARCH Command
Command
Type
Crescent Vector
Description
Force the Crescent Vector to reject the current GPS heading solution and begin a new search
Command
Format
$JATT,SEARCH<CR><LF>
Receiver
Response
$>
Additional
Information
The SEARCH function will not work if you have enabled the gyroaid feature (using the GYROAID
command). In this case you must cycle power to the receiver to have a new GPS solution computed.
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Hemisphere GPS Technical Reference v1.02
JATT,SPDTAU Command
Note: The JTAU,SPEED command provides identical functionality but works with Crescent and Eclipse products in addition to
Crescent Vector products.
Command
Type
Crescent Vector
Description
Set the speed time constant (0.0 to 3600.0 seconds) or query the current setting
This command allows you to adjust the level of responsiveness of the speed measurement provided in
the GPVTG message. The default value is 0.0 seconds of smoothing. Increasing the speed time constant
increases the level of speed measurement smoothing.
Command
Format
Set the speed time constant
$JATT,SPDTAU,spdtau<CR><LF>
where 'spdtau' is the new time constant that falls within the range of 0.0 to 200.0 seconds
The setting of this value depends upon the expected dynamics of the receiver. If the receiver will be in a
highly dynamic environment, you should set this to a lower value, since the filtering window will be
shorter, resulting in a more responsive measurement. However, if the receiver will be in a largely static
environment, you can increase this value to reduce measurement noise.
Query the current setting
$JATT,SPDTAU<CR><LF>
Receiver
Response
$>
Additional
Information
You can use the following formula to determine the COG time constant (Hemisphere GPS recommends
testing how the revised value works in practice):
2
spdtau (in seconds) = 10 / maximum acceleration (in m/s )
If you are unsure of the best value for this setting, it is best to be conservative and leave it at the default
setting:
128
•
Crescent Vector receivers: default of 0.0 seconds
•
Non-Crescent Vector receivers: default of LONG (900 seconds)
Commands and Messages
JATT,SUMMARY Command
Command
Type
Crescent Vector
Description
Display a summary of the current Crescent Vector settings
Command
Format
$JATT,SUMMARY<CR><LF>
Receiver
Response
$>JATT,SUMMARY,htau,hrtau,ptau,cogtau,spdtau,hbias,pbias,
hexflag<CR><LF>
where:
Component
Description
htau
Current heading time constant, in seconds
hrtau
Current heading rate time constant, in seconds
ptau
Current pitch time constant, in seconds
cogtau
Current course over ground time constant, in seconds
spdtau
Current speed time constant, in seconds
hbias
Current heading bias, in degrees
pbias
Current pitch/roll bias, in degrees
hexflag
Hex code that summarizes the heading feature status
Flag
'On'
Value
'Off'
Value
Gyro aiding
02
0
Negative tilt
01
0
Roll
08
0
Tilt aiding
02
0
Level
01
0
The 'hexflag' field is two separate hex flags:
•
'GN' - Value is determined by computing the sum of the gyro aiding and negative tilt values,
depending on whether they are on or off:
o
o
•
If the feature is on, their value is included in the sum
If the feature is off, it has a value of zero when computing the sum
'RMTL' - Value is determined in much the same way but by adding the values of roll, tilt aiding,
and level operation.
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For example, if gyro aiding, roll, and tilt aiding features were each on, the values of 'GN' and 'RMTL' would
be:
•
'GN' = hex (02 + 0) = hex (02) = 2
•
'RMTL' = hex (08 + 02) = hex (10) = A
• ‘GN-RMTL’ = 2A
The following tables summarize the possible feature configurations for the first 'GN' character and the
second 'RMTL' character.
JATT,SUMMARY 1st GN Character Configurations
GN Value
Gyro Value
Negative Tilt
0
Off
Off
1
Off
On
2
On
Off
3
On
On
JATT,SUMMARY 2nd RTML Character
Configurations
Example
Additional
Information
130
RMTL
Value
Roll
Tilt
Aiding
Level
0
Off
Off
Off
1
Off
Off
On
2
Off
On
Off
3
Off
On
On
8
On
Off
Off
9
On
Off
On
A
On
On
Off
B
On
On
On
$>JATT,SUMMARY,TAU:H=0.50,HR=2.00,COG=0.00,SPD=0.00,BIAS:H=0.00,P=0.00
,
FLAG_HEX:HF-RMTL=01
Commands and Messages
JATT,TILTAID Command
Command
Type
Crescent Vector
Description
Turn tilt aiding on or off or query the current setting
The Crescent Vector’s internal tilt sensors (accelerometers) may be enabled by default (see your specific
product manuals for further information).
The sensors act to reduce the RTK search volume, which improves heading startup and reacquisition
times. This improves the reliability and accuracy of selecting the correct heading solution by eliminating
other possible, erroneous solutions.
Command
Format
Turn tilt aiding on/off
Turn tilt aiding on:
$JATT,TILTAID,YES,<CR><LF>
Turn tilt aiding off:
$JATT,TILTAID,NO<CR><LF>
Query the current setting
$JATT,TILTAID<CR><LF>
Receiver
Response
Response to issuing command to turn tilt aiding on/off
$>
Response to querying the current setting
If setting is currently ON the response is:
$>JATT,TILTAID,ON
If setting is currently OFF the response is:
$>JATT,TILTAID,OFF
Additional
Information
Tilt aiding is required to increase the antenna separation of the Crescent Vector OEM beyond the default
0.5 m length.
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JATT,TILTCAL Command
Command
Type
Crescent Vector
Description
Calibrate the internal tilt sensors of the Crescent Vector
You can calibrate the tilt sensor of the Crescent Vector in the field but the Crescent Vector enclosure
must be horizontal when you calibrate.
The calibration process takes about two seconds. The calibration is automatically saved to memory for
subsequent power cycles.
Command
Format
$JATT,TILTCAL<CR><LF>
Receiver
Response
$>
Additional
Information
132
Commands and Messages
JBAUD Command
Command
Type
General Operation and Configuration
Description
Specify the baud rates of the receiver or query the current setting
Command
Format
Specify the baud rates
$JBAUD,R[,OTHER][,SAVE]<CR><LF>
where:
•
'R' = baud rate (4800, 9600, 19200, 38400, 57600, or 115200)
•
',OTHER' = optional field, enacts a change on the current port when you send the command
without it (and without the brackets) and enacts a change on the other port when you send the
command with it (without the brackets)
•
',SAVE' = optional field, saves the baud rate into flash memory so that if you reset power the
receiver will boot at the new baud rate (it may take several seconds to save the baud rate to
flash memory)
Query the current setting
$JBAUD[,OTHER]<CR><LF>
where:
•
Receiver
Response
',OTHER' = optional field, queries the current port when you send the command without it (and
without the brackets) and queries the other port when you send the command with it (without the
brackets)
$>JBAUD,R[,OTHER]
The response format is the same whether you specify the baud rates or query the current settings.
Example
Issue the following command to set the baud rate to 19200 on the current port:
$JBAUD,19200<CR><LF>
...the response is then:
$>JBAUD,19200
Issue the following command to set the baud rate to 9600 on the OTHER port and save it into memory:
$JBAUD,9600,OTHER,SAVE<CR><LF>
...the response is then:
$>JBAUD,9600,OTHER
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Additional
Information
Note: When saving the baud rate wait until you see the SAVE COMPLETE message before powering off
the receiver. See the JSAVE command for an example of this output.
The status of this command is also output when issuing the JSHOW command.
134
Commands and Messages
JBIN Command
Command
Type
General Operation and Configuration
Description
Enable the output of the various binary messages—most notably the Bin95 and Bin96 messages—to be
requested. The Bin95 and Bin96 messages contain all the information required for post processing.
Command
Format
$JBIN,MSG,R<CR><LF>
where:
Receiver
Response
•
'MSG' = binary message you want to output
•
'R' = message rate as shown in the following table
Message
Name
MSG
R (Hz)
Description
Bin1
1
20, 10, 2, 1, 0,
or .2
GPS position message (position and velocity
data)
Bin2
2
1 or 0
GPS DOPs (Dilution of Precision)
Bin62
62
1 or 0
GLONASS almanac information
Bin65
65
1 or 0
GLONASS ephemeris information
Bin66
66
20, 10, 2, 1, or 0
GLONASS L1 code and carrier phase
information
Bin69
69
1 or 0
GLONASS L1 diagnostic information
Bin76
76
20, 10, 2, 1, 0,
or .2
GPS L1/L2 code and carrier phase information
Bin80
80
1 or 0
SBAS data frame information
Bin89
89
1 or 0
SBAS satellite tracking information
Bin93
93
1 or 0
SBAS ephemeris information
Bin94
94
1 or 0
Ionospheric and UTC conversion parameters
Bin95
95
1 or 0
GPS ephemeris information
Bin96
96
20, 10, 2, 1, or 0
GPS L1 code and carrier phase information
Bin97
97
20, 10, 2, 1, 0,
or .2
Processor statistics
Bin98
98
1 or 0
Satellite and almanac information
Bin99
99
1 or 0
GPS L1 diagnostic information
$>
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Example
To output the Bin76 message at a rate of 10 Hz, issue the following command:
$JBIN,76,10<CR><LF>
Additional
Information
136
Higher update rates may be available with a subscription on Bin 1, 2, 96, 97 and 99.
Commands and Messages
JBOOT,OMNI Command
Command
Type
OmniSTAR
Description
Power down the OmniSTAR portion of the Eclipse engine and then power it back up. This allows you to
reboot the receiver to drop the satellite to which it is currently locked and retune to another satellite without
cycling the power of the Eclipse II. It also allows you to reset the HP resolution algorithm.
Command
Format
$JBOOT,OMNI<CR><LF>
Receiver
Response
$>
Additional
Information
JFREQ
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JCONN Command
Command
Type
General Operation and Configuration
Description
Create a virtual circuit between two ports to enable communication through the receiver to the device on
the opposite port
Command
Format
To connect two ports virtually:
$JCONN,P1,P2<CR><LF>
where P1 and P2 are a pair of the following: A,B,C,D or PortA,PortB,PortC,PortD
Examples
$JCONN,A,B<CR><LF>
$JCONN,PortA,PortB<CR><LF>
To disconnect virtual connection:
$JCONN,X<CR><LF>
Receiver
Response
$>
Additional
Information
Caution: Hemisphere GPS receivers with menus, such as an R Series, use JCONN within the menu
application. Any settings you make with JCONN on these products may disable the menu functions until
power is cycled.
138
Commands and Messages
JDIFF Command
Command
Type
General Operation and Configuration
Description
Specify or query the differential source of the receiver
Forces the system to go and use “diff” as the source.
Command
Format
Specify the differential mode
$JDIFF,DIFF[,SAVE]<CR><LF>
where:
•
'DIFF' (differential source) may be one of the following:
DIFF
Description
OTHER
Instruct the receiver to use external corrections input through the
opposite port that is communicating
THIS
Instruct the receiver to use external corrections input through the
same port that is communicating
PORTA or
PORTB or
PORTC or
PORTD
Instruct the receiver to use external corrections input through the
specified port
BEACON
Instruct the receiver to use RTCM corrections entering Port C at a
fixed rate of 9600 baud. This input does not have to be from a beacon
receiver, such as SBX. However, this is a common source of
corrections.
WAAS
Instruct the receiver to use SBAS. This is also the response when
running the local dif application as the base.
RTK
Response when running the local dif or rover RTK application for the
rover.
LBAND
Instruct the receiver to use OmniSTAR.
X
Instruct the receiver to use e-Dif mode
NONE
Instruct the receiver to operate in autonomous mode
•
',SAVE' = optional field, saves the differential source into flash memory so that if you reset power
the receiver will boot with the new differential source (it may take several seconds to save the
differential source to flash memory)
Query the current DIFF setting
$JDIFF<CR><LF>
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Receiver
Response
Receiver response when specifying the differential source
$>
Receiver response when querying the differential source
$>JDIFF,X
where 'X' is the differential source in the table above ('AUTO' is the response when queried in e-Dif)
Example
Issue the following command to query the receiver:
$JDIFF<CR><LF>
...and if the differential source is WAAS, the response is:
$>JDIFF,WAAS
Additional
Information
140
The status of this command is also output in the JSHOW message.
Commands and Messages
JDIFFX,EXCLUDE Command
Command
Type
General Operation and Configuration
Description
Specify the differential sources to be excluded from operating in a multi-differential application
Command
Format
$JDIFFX,EXCLUDE[,SBAS][,OMNIVBS][,OMNIHP][,RTCM2][,EDIF][,DFX][,CMR]
[,RTCM3][,ROX ]<CR><LF>
Receiver
Response
$>
Example
Issue the following command to exclude RTCM3:
$JDIFFX,EXCLUDE,RTCM3<CR><LF>
Additional
Information
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JDIFFX,GNSSOUT Command
Command
Type
General Operation and Configuration
Description
Specify GNSS output in correction formats or query the current setting
Command
Format
Specify the GNSS output
$JDIFFX,GNSSOUT,gnss,x<CR><LF>
where:
•
gnss = GNSS type to output in correction formats (GPS and/or GLONASS)
•
x = NO (do not output in correction formats) or YES (output in correction formats)
Query the current setting
Query what GNSS types are output in correction formats
$JDIFFX,GNSSOUT<CR><LF
Query if a specific GNSS type is output in correction formats
$JDIFFX,GNSSOUT,gnss<CR><LF
Receiver
Response
Receiver response when specifying the GNSS output
$>
Receiver response when querying the current output setting
Query what GNSS types are output in correction formats
$>JDIFFX,GNSSOUT<CR><LF
Query if a specific GNSS type is output in correction formats
$>JDIFFX,GNSSOUT,gnss,x<CR><LF>
where 'x' is YES or NO
Example
Query what GNSS types are output in correction formats
Command: $JDIFFX,GNSSOUT<CR><LF>
Response if just GPS: $>JDIFFX,GNSSOUT,GPS
Response if both GPS and GLONASS: $>JDIFFX,GNSSOUT,GPS,GLONASS
Query if GLONASS is output in correction formats
142
Commands and Messages
Command: $JDIFFX,GNSSOUT,GLONASS<CR><LF>
Response if GLONASS is not output: $>JDIFFX,GNSSOUT,GLONASS,NO
Specify that GPS is output in correction formats
Command: $JDIFFX,GNSSOUT,GPS,YES<CR><LF>
Response: $>JDIFFX,GNSSOUT,GPS
Additional
Information
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Hemisphere GPS Technical Reference v1.02
JDIFFX,INCLUDE Command
Command
Type
General Operation and Configuration
Description
Specify the differential sources to be allowed to operate in a multi-differential application
Command
Format
$JDIFFX,INCLUDE[,SBAS][,OMNIVBS][,OMNIHP][,RTCM2][,EDIF][,DFX][,CMR]
[,RTCM3][,ROX ]<CR><LF>
Receiver
Response
$>
Example
Issue the following command to include CMR:
$JDIFFX,INCLUDE,CMR<CR><LF>
Additional
Information
For example, if an Eclipse II receiver with SBAS, OmniSTAR, and RTK-base in the same application
(multi-diff) has no active OmniSTAR subscription:
1.
The receiver tries XP/HP and when it is not found, falls back to VBS.
2.
The receiver tries VBS and when it is not found, falls back to WAAS.
3.
No warnings when subscription has expired – user expects a certain level of accuracy with
OmniSTAR, not SBAS level accuracy.
If you do not actively watch the OmniSTAR end date, you could potentially use SBAS without knowing it.
This command limits the diff sources to ensure a certain level of accuracy is retained.
144
Commands and Messages
JDIFFX,SOURCE Command
Command
Type
General Operation and Configuration
Description
Query the receiver for the differential source
Command
Format
$JDIFFX,SOURCE<CR><LF>
Receiver
Response
$>JDIFFX,source
where 'source' is the differential source
Example
Response if OmniSTAR is the differential source
$>JDIFFX,SOURCE,LBAND
Response if RTK is the differential source through Port B
$>JDIFFX,SOURCE,PORTB
Additional
Information
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JDIFFX,TYPE Command
Command
Type
General Operation and Configuration
Description
Query the receiver for the differential type
Command
Format
$JDIFFX,TYPE<CR><LF>
Receiver
Response
$>JDIFF,type
where 'type' is the differential type
Example
Response if OmniSTAR HP (L2) is the differential type
$>JDIFFX,TYPE,OMNIHP
Response if OmniSTAR VBS (L1) is the differential type
$>JDIFFX,TYPE,OMNIVBS
Response if RTK (ROX) is the differential type
$>JDIFFX,TYPE,ROX
Additional
Information
146
Commands and Messages
JFLASH Command Overview
The JFLASH command is used to perform file operations via a USB flash drive on Eclipse and Eclipse II based receivers.
Command
Description
JFLASH,DIR
Display the files on a USB flash drive
JFLASH,FILE,CLOSE
Close an open file on a USB flash drive
JFLASH,FILE,NAME
Open a specific file, append to a specific file, or display the file name of the open file on a
USB flash drive
JFLASH,FILE,OPEN
Create and open a file with an automatically generated file name on a USB flash drive
JFLASH,FREESPACE
Display the free space in kilobytes (KB) on a USB flash drive
JFLASH,NOTIFY,CONNECT
Enable/disable the automatic response when a USB flash drive is inserted or removed
JFLASH,QUERYCONNECT
Manually verify if a USB flash drive is connected or disconnected
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JFLASH,DIR Command
Command
Type
General Operation and Configuration
Description
Display the files on a USB flash drive
You can only display files at the root level of the flash drive (you cannot navigate into subdirectories).
Command
Format
$JFLASH,DIR<CR><LF>
Receiver
Response
$>JFLASH,file1
$>JFLASH,file2
$>JFLASH,file3
...
$>JFLASH,filen
One line appears for each file at the root level of the flash drive.
Example
If you issue the $JFLASH,DIR command and the root level of the flash drive contains the following
files:
hemi_1.bin, hemi_2.bin, hemi_3.bin
the response is:
$>JFLASH,hemi_1.bin
$>JFLASH,hemi_2.bin
$>JFLASH,hemi_3.bin
Additional
Information
148
Commands and Messages
JFLASH,FILE,CLOSE Command
Command
Type
General Operation and Configuration
Description
Close an open file on a USB flash drive
Closing a file does not turn off the messages being written to the flash drive; it just closes the file so you
can safely remove the flash drive.
Caution: Close the file before removing the flash drive. Failure to do so may corrupt the file.
Command
Format
$JFLASH,FILE,CLOSE<CR><LF>
Receiver
Response
$>JFLASH,CLOSE mass_storage:0:\filename
Example
If you issue the $JFLASH,FILE,CLOSE command and the 'hemi_4.bin' file on the flash drive is
currently open, the response is:
$>JFLASH,CLOSE mass_storage:0:\HEMI_4.BIN
Additional
Information
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JFLASH,FILE,NAME Command
Command
Type
General Operation and Configuration
Description
Open a specific file, append to a specific file, or display the file name of the open file on a USB flash drive
Command
Format
Open a specific file (overwrite or append)
$JFLASH,FILE,NAME,filename[,APPEND]<CR><LF>
where:
•
'filename' is the name of the file and it must be a legal 8.3 file name
• ',APPEND' is an optional field that allows you to append data to the file
Warning: Using this command without the ',Append' option overwrites the existing file without warning.
Display the name of the open file
$JFLASH,FILE,NAME<CR><LF>
Receiver
Response
Response from issuing command to open an existing file or append to an existing file
$>JFLASH, OPEN mass_storage:0:\filename
Response from issuing command to display the name of the open file
$>JFLASH, mass_storage:0:\filename
If you attempt to display the name of the open file and no file is actually open the response is:
$>JFLASH, NO FILE OPEN
Example
If you issue the following command to open file hemi_4.bin on a USB flash drive:
$JFLASH,FILE,NAME,hemi_4.bin<CR><LF>
the response is:
$>JFLASH, mass_storage:0:\HEMI_4.BIN
Additional
Information
150
Commands and Messages
JFLASH,FILE,OPEN Command
Command
Type
General Operation and Configuration
Description
Create and open a file with an automatically generated file name (hemi_1.bin … hemi_99.bin) on a USB
flash drive (only 8.3 file format is allowed)
Command
Format
$JFLASH,FILE,OPEN<CR><LF>
Receiver
Response
$>JFLASH,OPEN mass_storage:0:\filename
where 'filename' is the name of the new file
Example
If you issue the $JFLASH,FILE,OPEN command and the root level of the flash drive contains the
following files:
hemi_1.bin, hemi_2.bin, hemi_3.bin
the response is:
$>JFLASH,OPEN mass_storage:0:\HEMI_4.bin
Additional
Information
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JFLASH,FREESPACE Command
Command
Type
General Operation and Configuration
Description
Display the free space in kilobytes (KB) on a USB flash drive
You can use a flash drive larger than 4GB; however, this command will not display a number greater than
4GB.
Command
Format
$JFLASH,FREESPACE<CR><LF>
Receiver
Response
$>JFLASH,FREESPACE,
numbytes bytes
where 'numbytes' is the number of kilobytes
Example
The following response indicates a USB flash drive with approximately 2GB of free space.
$>JFLASH,FREESPACE,
Additional
Information
152
2001731584 bytes
Commands and Messages
JFLASH,NOTIFY,CONNECT Command
Command
Type
General Operation and Configuration
Description
Enable/disable the automatic response when a USB flash drive is inserted or removed (if port is not
specified the response will be sent to the port that issued the command)
Command
Format
$JFLASH,NOTIFY,CONNECT,R[,PORT]<CR><LF>
where:
Receiver
Response
•
'R' is the message status variable (0 = Off, 1 = On)
•
',PORT' is an optional field you use to specify the port to which the response will be sent (if you do
not specify a port, the response is sent to the port from which you issued the command)
Response to issuing command to enable notification
$>
Response to inserting a flash drive if notification is enabled
$>JFLASH,CONNECTED
Response to removing a flash drive if notification is enabled
$>JFLASH,DISCONNECTED
Additional
Information
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JFLASH,QUERYCONNECT Command
Command
Type
General Operation and Configuration
Description
Manually verify if a USB flash drive is connected or disconnected
Command
Format
$JFLASH,QUERYCONNECT<CR><LF>
Receiver
Response
Response to verifying the connection status of a flash drive if the flash drive is connected
$>JFLASH,CONNECTED
$>
Response to verifying the connection status of a flash drive if the flash drive is
disconnected
$>JFLASH,DISCONNECTED
$>
Additional
Information
154
Commands and Messages
JFREQ Command
Command
Type
OmniSTAR
Description
Tune the OmniSTAR receiver (manually or automatically) or query the receiver for the current setting
Command
Format
Tune the OmniSTAR receiver
To manually tune the receiver:
$JFREQ,freq,symb<CR><LF>
where:
•
'freq' is the frequency in kHz (reply is in MHz)
• 'symb' is the symbol baud rate (1200 or 2400)
To auto-tune the receiver:
$JFREQ,0<CR><LF>
Note: You must restart the OmniSTAR receiver (either by cycling power to the OmniSTAR receiver or by
issuing the JBOOT,OMNI command) for changes to take effect.
Query the current setting
$JFREQ<CR><LF>
Receiver
Response
Response to issuing command to tune receiver
$>
Response to querying the current setting
$>JLBEAM,Sent sfreq,Used ufreq,Baud baud,Geo lon[,AUTO]
where:
Response
Component
Description
sfreq
Frequency to which the OmniSTAR receiver is instructed to tune (in this
example, 1557.8550 MHz)
ufreq
Frequency to which the OmniSTAR receiver is tuned
baud
Baud Rate of the signals being received
lon
Approximate longitude of the geostationary satellite to which the OmniSTAR
receiver is tuned
AUTO
[Optional Field]
'AUTO' appears at the end of the query response only when the OmniSTAR
receiver is in ‘auto-tune’ mode.
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Example
Manually Tune a Frequency (command and response)
$JFREQ,1557835,1200
$>
Auto-Tune a Frequency based on Geographic Location (command and response)
$JFREQ,0
$>
Query a Manually Tuned Receiver (response)
$>JLBEAM,Sent 1557.8350,Used 1557.8350,Baud 1200,Geo -101
Query an Auto-Tuned Receiver (response)
$>JLBEAM,Sent 1557.8550,Used 1557.8550,Baud 1200,Geo -101,AUTO
Additional
Information
The status of this command is also output when issuing the JSHOW command.
The following table provides frequency information for the OmniSTAR satellites. This information is subject
to change. Visit www.omnistar.com for up-to-date information.
Coverage Area
Longitude
Frequency
Baud Rate
Satellite
Name
Eastern U.S.
101 West
1557.8450
1200
MSV-E
Central U.S.
101 West
1557.8350
1200
MSV-C
Western U.S.
101 West
1557.8550
1200
MSV-W
North, Central,
and South America,
including the Caribbean
98 West
1535.1375
1200
AM-SAT
Asia,
Pacific Islands
109 East
1535.1375
1200
AP-SAT
Europe, Africa,
Middle East
25 East
1537.440
1200
EUSAT
Australia, Far East
160 East
1535.185
1200
OCSAT
If you are already locked onto an OmniSTAR signal, you will need to break lock on the OmniSTAR
satellite before JFREQ will manually tune to your new signal. To do this, either disconnect the antenna
momentarily, cycling power to the receiver, issuing the JBOOT,OMNI command, or block signal to the
antenna physically, for example by covering it with something metallic.
156
Commands and Messages
JGEO Command
Command
Type
SBAS
Description
Display information related to the current frequency of SBAS and its location in relation to the receiver’s
antenna
Command
Format
$JGEO[,ALL]<CR><LF>
where ',ALL' is an optional field that displays information for all SBAS satellites (including those not being
used)
Receiver
Response
$>JGEO,SENT=1575.4200,USED=1575.4200,PRN=prn,LON=lon,EL=ele,AZ=az
where:
Example
Response
Component
Description
JGEO
Message header
Sent=1575.4
200
Frequency sent to the digital signal processor
Used=1575.
4200
Frequency currently used by the digital signal processor
PRN=prn
WAAS satellite PRN number
Lon=-lon
Longitude of the satellite
El=ele
Elevation angle from the receiver antenna to the WAAS satellite, reference to
the horizon
AZ=az
Azimuth from the receiver antenna to the WAAS satellite, reference to the
horizon
To display information related to the current frequency of SBAS issue the following command:
$JGEO[,ALL]<CR><LF>
The response is then:
$>JGEO,SENT=1575.4200,USED=1575.4200,PRN=122,LON=-54,EL=9.7,AZ=114.0
To display information for dual SBAS satellites issue the following command:
$JGEO[,ALL]<CR><LF>
The response is:
$>JGEO,SENT=1575.4200,USED=1575.4200,PRN=122,LON=-54,EL=9.7,AZ=114.0
$>JGEO,SENT=1575.4200,USED=1575.4200,PRN=134,LON=178,EL=5.0,AZ=252.6
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The first line of output is identical to the output from the first JGEO query above; however, the second line
of output provides information on the WAAS satellite not being currently used. Both lines of output follow
the same format.
Additional
Information
158
Commands and Messages
JHP Command Overview
The JHP command is used to control the operation of the OmniSTAR HP/XP engine.
Command
Description
JHP,LIMIT
Specify the OmniSTAR HP/XP convergence threshold (range is 0.0 to 1.0 m) or
display the threshold as compared to the RMS value in the GPGST message
JHP,MODE,AUTOSEED
Enable or disable the AUTOSEED feature when operating in LBAND mode and
using OmniSTAR XP/HP service, or query the current setting
JHP,MODE,IGNORECONVEREGE
If using the JHP,LIMIT command to specify the OmniSTAR HP/XP convergence
threshold, use this command to set the receiver to ignore when the OmniSTAR
engine indicates it is converged or query the current setting
JHP,POS
Query the receiver for the stored position with standard deviations (StDevs) to be
used with the JHP,SEED command
JHP,POS,LAT,LON,HGT
Save lat, lon, hgt and optionally save corresponding standard deviations into
non-volatile memory, to be used with the JHP,SEED command
JHP,POS,LAT,LON,HGT,,,,OTHER
(For use with AUTOSEED feature) Save lat, lon, hgt and optionally save
corresponding standard deviations into non-volatile memory, to be used with the
JHP,MODE,AUTOSEED command
JHP,POS,OTHER
(For use with AUTOSEED feature) Query the receiver for the stored position
with standard deviations (StDevs) to be used with the JHP,MODE,AUTOSEED
command
JHP,POS,PRESENT
Save the current location (lat, lon, height) and standard deviations into nonvolatile memory (provided the sum of the location standard deviations (StDev) <
0.6 m) to be used with the JHP,SEED command
JHP,RESET,ACCURACY
Reset the HP convergence by forcing the solution to the current location but with
very large standard deviations
JHP,RESET,ENGINE
Reset the HP engine, forcing the solution to converge (this will also force an
AUTOSEED location to reconverge)
JHP,SEED
Initialize the OmniSTAR HP algorithm with the saved position and saved
standard deviations
JHP,SEED,LAT,LON,HGT
Initialize the OmniSTAR HP algorithm with the given coordinates and optional
standard deviations (this command has the combined effect of the
JHP,POS,LAT,LON,HGT and JHP,SEED commands)
JHP,STATIC
Place the OmniSTAR HP engine into or out of static mode, or query the current
setting
JHP,STATUS,AUTOSEED
Displays the status of the AUTOSEED initialization progress
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JHP,LIMIT Command
Command
Type
OmniSTAR
Description
Specify the OmniSTAR HP/XP convergence threshold (range is 0.0 to 1.0 m) or display the threshold as
compared to the RMS value in the GPGST message
Command
Format
Set the convergence threshold
$JHP,LIMIT,thresh<CR><LF>
where "thresh" is the threshold range of 0.000 to 1.000 m
Query the current setting (display convergence threshold)
$JHP,LIMIT<CR><LF>
Receiver
Response
Response to issuing command to set convergence threshold
$>
Response to querying the current setting
$>JHP,LIMIT,thresh
Example
Issue the following command to specify a threshold range of 0.5 m:
$JHP,LIMIT,0.5<CR><LF>
If you then issue $JHP,LIMIT<CR><LF> to query the receiver for the current threshold, the following
will appear:
$>JHP,LIMIT,0.500
Additional
Information
Use this to set a convergence threshold for defining when a GPGGA message will indicate a quality
indicator as fixed (quality indicator 4) rather than float (quality indicator 5). If you do not set a limit, the
receiver will use the limit defined in the OmniSTAR engine.
When setting a convergence threshold, use the JHP,MODE,IGNORECONV command to turn off the
automatically defined limit in the OmniSTAR engine.
160
Commands and Messages
JHP,MODE,AUTOSEED Command
Command
Type
OmniSTAR
Description
Enable or disable the AUTOSEED feature when operating in LBAND mode and using OmniSTAR XP/HP
service, or query the current setting
Warning! Hemisphere GPS does not recommend using the AUTOSEED feature when there is risk of the
antenna moving more than 2.5 cm (1 in) while the system is powered off.
Command
Format
Enable/disable AUTOSEED feature
To enable the AUTOSEED feature:
$JHP,MODE,AUTOSEED,YES<CR><LF>
To disable the AUTOSEED feature:
$JHP,MODE,AUTOSEED,NO<CR><LF>
Query the current setting
$JHP,MODE,AUTOSEED<CR><LF>
Receiver
Response
Response to issuing command to enable/disable AUTOSEED feature
$>
Response to querying the current setting
If setting is currently enabled the response is:
$>JHP,MODE,AUTOSEED,YES
If setting is currently disabled the response is:
$>JHP,MODE,AUTOSEED,NO
Additional
Information
JHP,POS,PRESENT, JHP,POS,LAT,LON,HGT, JHP,STATUS,AUTOSEED
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JHP,MODE,IGNORECONV Command
Command
Type
OmniSTAR
Description
If using the JHP,LIMIT command to specify the OmniSTAR HP/XP convergence threshold, use this
command to set the receiver to ignore when the OmniSTAR engine indicates it is converged (the threshold
setting stored with the JHP,LIMIT command is then used as the only determining criteria for indicating that
the solution has converged to the defined accuracy) or query the current setting
Command
Format
Ignore/accept OmniSTAR engine convergence indication
To ignore OmniSTAR engine convergence indication:
$JHP,MODE,IGNORECONV,YES<CR><LF>
To accept OmniSTAR engine convergence indication:
$JHP,MODE,IGNORECONV,NO<CR><LF>
Query the current setting
$JHP,MODE,IGNORECONV<CR><LF>
Receiver
Response
Response to issuing command to ignore/accept OmniSTAR engine convergence indication
$>
Response to querying the current setting
If currently set to ignore the response is:
$>JHP,MODE,IGNORECONV,YES
If currently set to accept the response is:
$>JHP,MODE,IGNORECONV,NO
Additional
Information
162
If you set a convergence limit using the JHP,LIMIT command, using JHP,MODE,IGNORECONV,NO will
require BOTH the predefined OmniSTAR convergence limit AND the value entered in JHP,LIMIT to be met
before the GPGGA message will indicate a quality indicator of 4, meaning “converged”.
Commands and Messages
JHP,POS Command
Command
Type
OmniSTAR
Description
Query the receiver for the stored position with standard deviations (StDevs) to be used with the JHP,SEED
command
Command
Format
$JHP,POS<CR><LF>
Receiver
Response
Response if there is a saved position
$>JHP,POS,LAT,LON,HEIGHT,STDEV
Response if there is no saved position
$>JHP,POS,LAT,LON,HEIGHT
Example
If you issue the command and there is a saved position, the response will be similar to the following:
$>JHP,POS,
Additional
Information
JHP,SEED
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JHP,POS,LAT,LON,HGT Command
Command
Type
OmniSTAR
Description
Save lat, lon, hgt and optionally save corresponding standard deviations into non-volatile memory, to be
used with the JHP,SEED command
Command
Format
$JHP,POS,lat,lon,hgt[,latstdev,lonstdev,hgtstdev]<CR><LF>
where
Command
Component
Description
lat
Latitude in decimal degrees
lon
Longitude in decimal degrees
hgt
You must enter HEIGHT as ellipsoidal height in meters.
Ellipsoidal height can be calculated by adding the altitude and the geoidal
separation, both available from the GPGGA message.
Example:
$GPGGA,173309.00,5101.04028,N,11402.38289,W,2,07,1.4,1
071.0,
M,- 17.8,M,6.0, 0122*48
ellipsoidal height = 1071.0 + (-17.8) = 1053.2 meters
latstdev
Optional field
Standard deviation of latitude in meters
lonstdev
Optional field
Standard deviation of longitude in meters
hgtstdev
Optional field
Standard deviation of height in meters
Receiver
Response
$>
Additional
Information
JHP,SEED
164
Commands and Messages
JHP,POS,LAT,LON,HGT,,,,OTHER Command
Command
Type
OmniSTAR
Description
For use with AUTOSEED feature
Save lat, lon, hgt and optionally save corresponding standard deviations into non-volatile memory, to be used
with the JHP,MODE,AUTOSEED command
Command
Format
$JHP,POS,lat,lon,hgt[,latstdev,lonstdev,hgtstdev],OTHER<CR><LF>
where
Command
Component
Description
lat
Latitude in decimal degrees
lon
Longitude in decimal degrees
hgt
You must enter HEIGHT as ellipsoidal height in meters.
Ellipsoidal height can be calculated by adding the altitude and the geoidal
separation, both available from the GPGGA message.
Example:
$GPGGA,173309.00,5101.04028,N,11402.38289,W,2,07,1.4,107
1.0,
M,- 17.8,M,6.0, 0122*48
ellipsoidal height = 1071.0 + (-17.8) = 1053.2 meters
latstdev
Optional field
Standard deviation of latitude in meters
lonstdev
Optional field
Standard deviation of longitude in meters
hgtstdev
Optional field
Standard deviation of height in meters
Receiver
Response
$>
Additional
Information
JHP,MODE,AUTOSEED, JHP,POS,OTHER
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JHP,POS,OTHER Command
Command
Type
OmniSTAR
Description
For use with AUTOSEED feature
Query the receiver for the stored position with standard deviations (StDevs) to be used with the
JHP,MODE,AUTOSEED command
Command
Format
$JHP,POS,OTHER<CR><LF>
Receiver
Response
Additional
Information
166
JHP,MODE,AUTOSEED
Commands and Messages
JHP,POS,PRESENT Command
Command
Type
OmniSTAR
Description
Save the current location (lat, lon, height) and standard deviations into non-volatile memory (provided the
sum of the location standard deviations (StDev) < 0.6 m) to be used with the JHP,SEED command
Command
Format
$JHP,POS,PRESENT<CR><LF>
Receiver
Response
$>
Additional
Information
JHP,SEED
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JHP,RESET,ACCURACY Command
Command
Type
OmniSTAR
Description
Reset the HP convergence by forcing the solution to the current location but with very large standard
deviations
Command
Format
$JHP,RESET,ACCURACY<CR><LF>
Receiver
Response
$>
Additional
Information
You can watch the GPGGA message quality indicator and the GPGST message estimated accuracy
values to see the effect of resetting the OmniSTAR HP accuracy.
168
Commands and Messages
JHP,RESET,ENGINE Command
Command
Type
OmniSTAR
Description
Reset the HP engine, forcing the solution to converge (this will also force an AUTOSEED location to
reconverge)
Command
Format
$JHP,RESET,ENGINE<CR><LF>
Receiver
Response
$>
Additional
Information
You can watch the GPGGA message quality indicator and the GPGST message estimated accuracy
values to see the effect of resetting the OmniSTAR HP engine.
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JHP,SEED Command
Command
Type
OmniSTAR
Description
Initialize the OmniSTAR HP algorithm with the saved position and saved standard deviations
•
To enter a saved position, see the JHP,POS,LAT,LON,HGT and JHP,POS,PRESENT commands
•
Alternately, use the ,OTHER option to seed using the location stored for use with the
JHP,MODE,AUTOSEED feature
Command
Format
$JHP,SEED[,OTHER]<CR><LF>
Receiver
Response
$>
If the coordinates to which you are attempting to initialize are not close enough to your current location, the
response is:
$>JHP,SEED,Current Position Too Far From Seed
Additional
Information
170
JHP,POS,LAT,LON,HGT, JHP,POS,PRESENT
Commands and Messages
JHP,SEED,LAT,LON,HGT Command
Command
Type
OmniSTAR
Description
Initialize the OmniSTAR HP algorithm with the given coordinates and optional standard deviations (this
command has the combined effect of the JHP,POS,LAT,LON,HGT and JHP,SEED commands)
Command
Format
$JHP,SEED,LAT,LON,HGT[,LatStDev,LonStDev,HgtStDev]
Receiver
Response
$>
If the coordinates to which you are attempting to initialize are not close enough to your current location, the
response is:
$>JHP,SEED,Current Position Too Far From Seed
Additional
Information
JHP,POS,LAT,LON,HGT, JHP,SEED
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JHP,STATIC Command
Command
Type
OmniSTAR
Description
Place the OmniSTAR HP engine into or out of static mode, or query the current setting
Command
Format
Place HP into or out of static mode
To place HP into static mode:
$JHP,STATIC,YES<CR><LF>
To place HP out of static mode:
$JHP,STATIC,NO<CR><LF>
Query the current setting
$JHP,STATIC<CR><LF>
Receiver
Response
Response to issuing command to place HP into or out of static mode
$>
Response to querying the current setting
If HP is currently in static mode the response is:
$>JHP,STATIC,YES
If HP is currently not in static mode the response is:
$>JHP,STATIC,NO
Additional
Information
172
If the receiver detects motion while in static mode, it changes its status to effectively the same as issuing
the $JHP,STATIC,NO command.
Commands and Messages
JHP,STATUS,AUTOSEED Command
Command
Type
OmniSTAR
Description
Displays the status of the AUTOSEED initialization progress
Command
Format
$JHP,STATUS,AUTOSEED<CR><LF>
Receiver
Response
$>JHP,STATUS,AUTOSEED,status
Where 'status' is one of following:
Additional
Information
•
NoHP
•
Disabled
•
Seeding
•
Failed_NoSeed
•
Failed_Moved
•
Failed_Timeout
•
Success
You can watch the GPGGA message quality indicator and the GPGST message estimated accuracy
values to see the effect of resetting the OmniSTAR HP accuracy.
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JI Command
Command
Type
General Operation and Configuration
Description
Display receiver information, such as its serial number and firmware version
Command
Format
$JI<CR><LF>
Receiver
Response
$>JI,SN,FLT,HW,PROD,SDATE,EDATE,SW,DSP<CR><LF>
where:
Example
Response
Component
Description
SN
Serial number of the GPS engine
FLT
Fleet number
HW
Hardware version
PROD
Production date code
SDATE
Subscription begin date when running OmniSTAR application; not applicable
when running all other applications
EDATE
Subscription expiration date when running OmniSTAR application OR receiver
subscription code when running all other applications (see Interpreting the $JI
and $JK 'Date'/Subscription Codes to determine the meaning of the
subscription code)
SW
Application software version number
DSP
DSP version (only valid for OmniSTAR applications)
From a Crescent Vector:
$>JI,452204,1,7,02122009,01/01/1900,01/01/3007,1.5Pa,46
From a Crescent with OmniSTAR:
$>JI,883765,1,7,12052010,01/06/1980,06/30/2011,4.9Pa,11
Additional
Information
174
Commands and Messages
JK Command
Command
Type
General Operation and Configuration
Description
Subscribe the receiver to various options, such as higher update rates, e-Dif (or base station capability)
or L-Dif
or
Query for the current subscription expiration date when running OmniSTAR application or the receiver
subscription code when running all other applications
Command
Format
Subscribe the receiver to specific options
$JK,X…<CR><LF>
where 'X…' is the subscription key provided by Hemisphere GPS and is 10 characters in length
Query the current setting
$JK<CR><LF>
Receiver
Response
Response to issuing command to subscribe
$>
Response to querying the current setting when running OmniSTAR applications
$>JK,EndDate,1HzOnly
where:
•
'EndDate' is the subscription end date
•
'1HzOnly' has a value of 1 if the receiver is limited to 1 Hz output (if the receiver is subscribed to
a minimum of 10 Hz output this field is omitted)
Response to querying the current setting when running all other applications
$>JK,SubscriptionCode,1HzOnly
where:
Example
•
'SubscriptionCode' is the subscription code (see Interpreting the $JI and $JK 'Date'/Subscription
Codes to determine the meaning of the subscription code)
•
'1HzOnly' has a value of 1 if the receiver is limited to 1 Hz output (if the receiver is subscribed to
a minimum of 10 Hz output this field is omitted)
If you query the receiver for the current setting when running OmniSTAR applications the response will
appear similar to the following:
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$>JK,06/30/2011,0
If you query the receiver for the current setting when running any other application the response will
appear similar to the following (Crescent Vector example response shown):
$>JK,01/01/3007,7
Additional
Information
176
Commands and Messages
JLBEAM Command
Command
Type
OmniSTAR
Description
Display the information of each spot beam currently in use by the OmniSTAR receiver
Command
Format
$JLBEAM<CR><LF>
Receiver
Response
$>JLBEAM,Sent freq,Used freq,Baud xxx,Geo xxx
(1)
$>JLBEAM,freq1,lon1,lat1,baud1,satlon1
(2)
.
.
.
$>JLBEAM,freqn,lonn,latn,baudn,satlonn
where:
Response
Component
Description
"Sent" freq
Frequency sent to the digital signal processor (DSP)
"Used" freq
Frequency currently being used by the digital signal processor (DSP)
"Baud"
xxxx
Currently used baud rate of the acquired signal
"Geo" xxx
Currently used satellites longitude (in degrees)
The output second line components are described in the following table:
Example
Response
Component
Description
freq
Frequency of the spot beam
lon
Longitude of the center of the spot beam (in degrees)
lat
Latitude of the center of the spot beam (in degrees)
baud
Baud rate at which this spot beam is modulated
satlon
Satellites longitude (in degrees)
$>JLBEAM,Sent 1551.4890,Used 1551.4890,Baud 1200,Geo -101
$>JLBEAM,1556.8250,-88,45,1200,(-101)
$>JLBEAM,1554.4970,-98,45,1200,(-101)
$>JLBEAM,1551.4890,-108,45,1200,(-101)
$>JLBEAM,1531.2300,25,50,1200,(16)
$>JLBEAM,1535.1375,-75,0,1200,(-98)
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$>JLBEAM,1535.1375,-165,13,1200,(-98)
$>JLBEAM,1535.1525,20,6,1200,(25)
$>JLBEAM,1558.5100,135,-30,1200,(160)
$>JLBEAM,1535.1375,90,15,1200,(109)
$>JLBEAM,1535.1375,179,15,1200,(109)
Additional
Information
178
Commands and Messages
JLIMIT Command
Command
Type
General Operation and Configuration
Description
Set the threshold of estimated horizontal performance for which the DGPS position LED is illuminated or
query the current setting
Command
Format
Set the threshold of estimated horizontal performance
$JLIMIT,LIMIT<CR><LF>
where 'LIMIT' is the new limit in meters
Query the current setting
$JLIMIT<CR><LF>
Receiver
Response
Receiver response when setting the threshold of estimated horizontal performance
$>
Receiver response when querying the current threshold of estimated horizontal performance
$>JLIM,RESID,LIMIT
where 'LIMIT' is the limit in meters
Example
To set the threshold to 5 m issue the following command:
$JLIMIT,5<CR><LF>
If you then query the receiver with
$JLIMIT<CR><LF> the response is:
$JLIM,RESID,5.00
Additional
Information
The default value for this parameter is a conservative 10.00 m.
The status of this command is also output in the JSHOW message.
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JLXBEAM Command
Command
Type
OmniSTAR
Description
Display spot beam debug information
Command
Format
$JLXBEAM<CR><LF>
Receiver
Response
$>JLBEAMEX
$> Beam:1,DDSfreq1,symbol1,lon1,lat1,lonrad1,latrad1,beamrot1,satlon1,*
$> Beam:2,DDSfreq2,symbol2,lon2,lat2,lonrad2,latrad2,beamrot2,satlon2,*
.
.
.
$> Beam:n,DDSfreqn,symboln,lonn,latn,lonradn,latradn,beamrotn,satlonn,*
where:
Example
180
Response
Component
Description
DDSfreq
DDS frequency
symbol
Symbol rate used for that particular spot beam
lon
Longitude of the spot beam centroid
lat
Latitude of the spot beam centroid
lonrad
Longitude radius of the spot beam
latrad
Latitude radius of the spot beam
beamrot
Rotation angle of the spot beam
satlon
Longitude of the L-band satellite
*
Reserved
$>JLBEAMEX
$> Beam:22,1535125000,600,-26,40,2,41,0,9999,*
$> Beam:21,1535157500,600,65,30,31,18,-21,64,*
$> Beam:13,1535185000,1200,136,-25,23,28,-40,144,*
$> Beam:13,1535185000,1200,172,-40,13,26,-26,144,*
$> Beam:24,1557835000,1200,-100,49,6,28,0,-101,*
$> Beam:24,1557835000,1200,-101,66,12,6,0,-101,*
$> Beam:25,1557845000,1200,-74,52,12,30,-30,-101,*
$> Beam:26,1557855000,1200,-122,45,11,30,25,-101,*
$> Beam:8,1535137500,1200,-85,2,30,20,-5,-98,*
$> Beam:8,1535137500,1200,-60,-25,34,36,-20,-98,*
$> Beam:4,1535137500,1200,109,2,14,19,-27,109,*
Commands and Messages
$>
$>
$>
$>
Beam:4,1535137500,1200,140,38,27,51,-56,109,*
Beam:7,1537440000,1200,23,-2,29,49,50,25,*
Beam:7,1537440000,1200,14,59,41,23,34,25,*
Beam:7,1537440000,1200,11,28,17,24,0,25,*
Additional
Information
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JMASK Command
Command
Type
GPS
Description
Specify the elevation cutoff mask angle for the GPS engine
Any satellites below this mask angle will be ignored even if available. The default angle is 5° because
satellites available below this angle will have significant tropospheric refraction errors.
Command
Format
$JMASK,E<CR><LF>
where the elevation mask cutoff angle 'E' may be a value from 0 to 60°
Receiver
Response
$>
Example
To specify the elevation cutoff mask angle to 10° issue the following command:
$JMASK,10<CR><LF>
Additional
Information
182
To query the receiver for the current setting, issue the JSHOW command.
Commands and Messages
JMODE Overview
The JMODE command is used to control various GPS tracking parameters.
Command
Description
JMODE
Query receiver for status of JMODE settings
JMODE,FOREST
Turn the higher gain functionality (for tracking under canopy) on/off or query the current setting
JMODE,GPSONLY
Set the receiver to use GPS data in the solution or query the current setting (if GLONASS is
available, setting to YES will cause the receiver to only use GPS data)
JMODE,L1ONLY
Set the receiver to use L1 data even if L2 data is available or query the current setting
JMODE,MIXED
Include satellites that do not have DGPS or SBAS corrections in the solution
JMODE,NULLNMEA
Enable/disable output of NULL fields in NMEA 0183 messages when no there is no fix (when
position is lost)
JMODE,SBASR
Enable/disable SBAS ranging
JMODE,TIMEKEEP
Enable/disable continuous time updating in NMEA 0183 messages when there is no fix (when
position is lost)
JMODE,TUNNEL
Enable/disable faster reacquisition after coming out of a tunnel or query the current setting
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JMODE Command
Command
Type
General Operation and Configuration
Description
Query receiver for status of JMODE settings
Command
Format
$JMODE<CR><LF>
Receiver
Response
$>JMODES[,BASE][,FOREST][,GPSONLY][,L1ONLY][,MIXED][,NULLNMEA][,SBASR]
[,TIMEKEEP][,TUNNEL][,WIDESEARCH]
Example
If FOREST and TUNNEL are set to ON and all others ( MIXED, NULLNMEA, SBASR, and TIMEKEEP) are
set to OFF and you issue the JMODE command the receiver response will be:
$JMODES,TUNNEL,FOREST
If all features are set to OFF and you issue the JMODE command the receiver response will be:
$JMODES
Additional
Information
The status of this command is also output in the JSHOW response. For example, if TUNNEL is set to ON
and all other JMODE options are set to OFF then the JMODE part of the response to the JSHOW command
is as follows:
$>JSHOW,MODES,TUNNEL
184
Commands and Messages
JMODE,FOREST Command
Command
Type
General Operation and Configuration
Description
Turn the higher gain functionality (for tracking under canopy) on/off or query the current setting.
This command is useful if you are trying to maximize the likelihood of calculating a position, but are willing
to sacrifice accuracy. See also JMODE,MIXED.
Command
Format
Turn enable/disable high gain functionality
To enable high gain functionality:
$JMODE,FOREST,YES<CR><LF>
To disable high gain functionality:
$JMODE,FOREST,NO<CR><LF>
Query the current setting
$JMODE,FOREST<CR><LF>
Receiver
Response
Response to issuing command to turn functionality on/off
$>
Response to querying the current setting
If high gain functionality is currently enabled the response is:
$>JMODE,FOREST,ON
If high gain functionality is currently disabled the response is:
$>JMODE,FOREST,OFF
Additional
Information
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JMODE,GPSONLY Command
Command
Type
General Operation and Configuration
Description
Set the receiver to use GPS data in the solution or query the current setting (if GLONASS is available,
setting to YES will cause the receiver to only use GPS data)
Command
Format
Enable/disable GPS-only operation
Enable GPS-only operation:
$JMODE,GPSONLY,YES<CR><LF>
Disable GPS-only operation (use GLONASS as well if available):
$JMODE,GPSONLY,NO<CR><LF>
Query the current setting
$JMODE,GPSONLY<CR><LF>
Receiver
Response
Response to issuing command to turn enable/disable GPS-only operation
$>
Response to querying the current setting
If GPS-only operation is currently enabled the response is:
$>JMODE,GPSONLY,YES
If GPS-only operation is currently disabled the response is:
$>JMODE,GPSONLY,NO
Additional
Information
186
Commands and Messages
JMODE,L1ONLY Command
Command
Type
General Operation and Configuration
Description
Set the receiver to use L1 data even if L2 data is available or query the current setting:
Command
Format
•
When set to YES receiver will use OmniSTAR VBS or L1 RTK
•
When set to NO receiver will use OmniSTAR XP/HP or L1/L2 RTK
Set receiver to use/not use L1 data even if L2 data is available
To use L1 data (even if L2 data is available):
$JMODE,L1ONLY,YES<CR><LF>
To use L2 data if it is available:
$JMODE,L1ONLY,NO<CR><LF>
Query the current setting
$JMODE,L1ONLY<CR><LF>
Receiver
Response
Response to issuing command to turn functionality on/off
$>
Response to querying the current setting
If the receiver is currently using L1 data only even if L2 data is available the response is:
$>JMODE,L1ONLY,YES
If the receiver is currently using L2 data if it is available the response is:
$>JMODE,L1ONLY,NO
Additional
Information
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JMODE,MIXED Command
Command
Type
General Operation and Configuration
Description
Include satellites that do not have DGPS or SBAS corrections in the solution
This command is useful if you are trying to maximize the likelihood of calculating a position, but are willing
to sacrifice accuracy. See also JMODE,FOREST.
Command
Format
To include/exclude satellites without DGPS or SBAS corrections
To include satellites without DGPS or SBAS corrections:
$JMODE,MIXED,YES<CR><LF>
To exclude satellites without DGPS or SBAS corrections:
$JMODE,MIXED,NO<CR><LF>
Query the current setting
$JMODE,MIXED<CR><LF>
Receiver
Response
Response to issuing command to include/exclude satellites without DGPS or SBAS corrections
$>
Response to querying the current setting
If satellites without differential corrections are currently included the response is:
$>JMODE,MIXED,ON
If satellites without differential corrections are currently excluded the response is:
$>JMODE,MIXED,OFF
Additional
Information
188
Commands and Messages
JMODE,NULLNMEA Command
Command
Type
General Operation and Configuration
Description
Enable/disable output of NULL fields in NMEA 0183 messages when no there is no fix (when position is
lost)
This only applies to position portion of the messages; it does not affect the time portion of the message. If
this setting is disabled and position is lost then the positioning parameters of the message from the most
recent known position are repeated (instead of being NULL if enabled).
Command
Format
Enable/disable output of NULL fields in NMEA 0183 messages
To enable output:
$JMODE,NULLNMEA,YES<CR><LF>
To disable output:
$JMODE,NULLNMEA,NO<CR><LF>
Query the current setting
$JMODE,NULLNMEA<CR><LF>
Receiver
Response
Response to issuing command to enable/disable output of NULL fields in NMEA 0183 messages
$>
Response to querying the current setting
If setting is currently enabled the response is:
$>JMODE,NULLNMEA,ON
If setting is currently disabled the response is:
$>JMODE,NULLNMEA,OFF
Example
If the most recent GPGGA message is as follows:
$GPGGA,220715.00,3333.4254353,N,11153.3506065,W,2,10,1.0,406.614,M,26.294,M,6.0,1001*70
...and then position is lost and JMODE,NULLNMEA is set to OFF the GPGGA message repeats as follows
(most recent known values do not change):
$GPGGA,220715.00,3333.4254353,N,11153.3506065,W,2,10,1.0,406.614,M,26.294,M,6.0,1001*70
For the same message, if position is lost and JMODE,NULLNMEA is set to ON the GPGGA message
repeats as follows (position parameters are NULL):
$GPGGA,220716.00,,,,,0,,,,M,,M,,*48
Additional
Information
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JMODE,SBASR Command
Command
Type
General Operation and Configuration
Description
Enable/disable SBAS ranging
Command
Format
Enable/disable SBAS ranging
To enable SBAS ranging:
$JMODE,SBASR,YES<CR><LF>
To disable SBAS ranging:
$JMODE,SBASR,NO<CR><LF>
Query the current setting
$JMODE,SBASR<CR><LF>
Receiver
Response
Response to issuing command to enable/disable SBAS ranging
$>
Response to querying the current setting
If setting is currently enabled the response is:
$>JMODE,SBASR,ON
If setting is currently disabled the response is:
$>JMODE,SBASR,OFF
Additional
Information
190
Commands and Messages
JMODE,TIMEKEEP Command
Command
Type
General Operation and Configuration
Description
Enable/disable continuous time updating in NMEA 0183 messages when there is no fix (when position is
lost)
When position is lost the time is the only parameter in the message that continues to update; all other
parameters remain the same.
Command
Format
Enable/disable continuous time updating
To enable continuous time updating:
$JMODE,TIMEKEEP,YES<CR><LF>
To disable continuous time updating:
$JMODE,TIMEKEEP,NO<CR><LF>
Query the current setting
$JMODE,TIMEKEEP<CR><LF>
Receiver
Response
Response to issuing command to enable/disable continuous time updating
$>
Response to querying the current setting
If setting is currently enabled the response is:
$>JMODE,TIMEKEEP,ON
If setting is currently disabled the response is:
$>JMODE,TIMEKEEP,OFF
Additional
Information
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JMODE,TUNNEL Command
Command
Type
General Operation and Configuration
Description
Enable/disable faster reacquisition after coming out of a tunnel or query the current setting
Command
Format
Enable/disable faster reacquisition after coming out of a tunnel
To enable faster reacquisition:
$JMODE,TUNNEL,YES<CR><LF>
To disable faster reacquisition:
$JMODE,TUNNEL,NO<CR><LF>
Query the current setting
$JMODE,TUNNEL<CR><LF>
Receiver
Response
Response to issuing command to turn functionality on/off
$>
Response to querying the current setting
If setting is currently enabled the response is:
$>JMODE,TUNNEL,ON
If setting is currently disabled the response is:
$>JMODE,TUNNEL,OFF
Additional
Information
192
Commands and Messages
JMSG99 Command
Type
Crescent Vector
Description
Change the output in the Bin99 message to be from the specified antenna
Format
$JMSG99,0
where '0' is used view the primary antenna SNR (default)
$JMSG99,1
where '1' is used view the secondary antenna SNR
Receiver
Response
$>
Other
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JNMEA,GGAALLGNSS Command
Command
Type
GLONASS
Description
Configure the GGA string to include full GNSS information (the number of used GLONASS satellites will be
included in the GPGGA message) or query the current setting
The GGA message is only supposed to report position and satellite information based on the GPS
constellation. The combined GPS and GLONASS position and satellite data should be reported in the
GNSS message, but some users with older equipment cannot utilize this message. This command allows
users with older equipment that require a GGA message to be able to utilize and take advantage of the
larger constellation of GPS and GLONASS satellites.
Command
Format
Include/exclude full GNSS information in GGA string
To include full GNSS information in GGA string:
$JNMEA,GGAALLGNSS,YES<CR><LF>
To exclude full GNSS information from GGA string:
$JNMEA,GGAALLGNSS,NO<CR><LF>
Query the current setting
$JNMEA,GGAALLGNSS<CR><LF>
Receiver
Response
Include/exclude full GNSS information in GGA string
$>
Query the current setting
If set to yes, querying the current setting returns the following:
$>JNMEA,GGAALLGNSS,YES
If set to no, querying the current setting returns the following:
$>JNMEA,GGAALLGNSS,NO
Additional
Information
194
Commands and Messages
JNMEA,PRECISION Command
Command
Type
GPS, Local Differential and RTK, OmniSTAR
Description
Specify or query the number of decimal places to output in the GPGGA and the GPGLL messages or query
the current setting
Command
Format
Specify the number of decimal places
$JNMEA,PRECISION,x<CR><LF>
where 'x' specifies the number of decimal places from 1 to 8
Query the current setting
$JNMEA,PRECISION<CR><LF>
Receiver
Response
Specify the precision
$>
Query the current setting
$>JNMEA,PRECISION,x
where 'x' refers to the number of decimal places to output
Additional
Information
When using RTK or OmniSTAR HP/XP, Hemisphere GPS recommends you set JNMEA,PRECISION to at
least 7 decimal places. High accuracy positioning techniques require at least 7 decimal places to maintain
millimeter (mm) accuracy.
This command is the same as JNP.
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JNP Command
Command
Type
GPS, Local Differential and RTK, OmniSTAR
Description
Specify or query the number of decimal places to output in the GPGGA and the GPGLL messages or
query the current setting
Command
Format
Specify the number of decimal places
$JNP,x<CR><LF>
where 'x' specifies the number of decimal places from 1 to 8
Query the current setting
$JNP<CR><LF>
Receiver
Response
Specify the number of decimal places to output
$>
Query the current setting
$>JNP,x
where 'x' refers to the number of decimal places to output
Additional
Information
When using RTK or OmniSTAR HP/XP, Hemisphere GPS recommends you set JNP to at least 7 decimal
places. High accuracy positioning techniques require at least 7 decimal places to maintain millimeter
(mm) accuracy.
This command is the same as JNMEA,PRECISION.
196
Commands and Messages
JOFF Command
Command
Type
GPS
Description
Turn off all data messages being output through the current port or other port (or Port C), including any
binary messages such as Bin95 and Bin96
Command
Format
$JOFF[,OTHER]<CR><LF>
When you specify the ',OTHER' data field (without the brackets), this command turns off all messages on
the other port. There are no variable data fields for this message.
You can issue this command as follows to turn off all messages on Port C:
$JOFF,PORTC<CR><LF>
Receiver
Response
$>
Additional
Information
To turn off all data messages being output through all ports, including any binary messages such as
Bin95 and Bin96, see the JOFF,ALL command
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JOFF,ALL Command
Command
Type
GPS
Description
Turn off all data messages being output through all ports, including any binary messages such as Bin95
and Bin96
Command
Format
$JOFF,ALL<CR><LF>
Receiver
Response
$>
Additional
Information
To turn off all data messages being output through a single port, including any binary messages such as
Bin95 and Bin96, see the JOFF command
198
Commands and Messages
JOMS Command
Command
Type
OmniSTAR
Description
Request the raw OmniSTAR subscription information
Command
Format
$JOMS
Receiver
Response
$>JOMS,Opt,Source,Type,AccrReduction,SDate,EDate,HourGlass,
ExtTime,LinkVector,SW
Example
Response
Component
Description
Opt
VBS subscription: Indicates a WET or DRY subscription
HP/XP subscription: Subscribed service level (varies according to the services
subscribed from OmniSTAR, contents defined by OmniSTAR)
Source
VBS subscription: RTCM source ID, VBS, or VRC
HP/XP subscription: Not applicable
Type
Subscription type (VBS, XP, HP, G2 etc; contents defined by OmniSTAR)
AccrReduct
ion
Not used
SDate
Subscription start date
EDate
Subscription end date
HourGlass
Seconds of metered time
ExtTime
Seconds of extension
LinkVector
Hexadecimal mask of links
SW
OmniSTAR library version, contents defined by OmniSTAR
"Opt = VBS subscription" example
$>JOMS,DRY,ALL,VBS,0,01/06/2000,01/06/2001,0,0,1E00,1.43
"Opt = HP/XP subscription" example
$>JOMS,HPG2-GLO,0,GPG2,0,09/01/2010,09/01/2010,0,0,FFFFFFFF,HP 5.22
Additional
Information
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JPOS Command
Command
Type
General Operation and Configuration
Description
Speed up the initial acquisition when changing continents with the receiver or query the receiver for the
current position of the receiver (for example, powering up the receiver for the first time in Europe after it
has been tested in Canada)
The command enables the receiver to begin the acquisition process for the closest SBAS spot beams.
This saves some time with acquisition of the SBAS service. However, use of this message is typically not
required because of the quick overall startup time of the receiver module.
Command
Format
Specify the latitude and longitude
$JPOS,LAT,LON<CR><LF>
where both 'LAT' and 'LON':
•
Must be entered in decimal degrees
• Do not need to be more accurate than half a degree
Query the current setting
$JPOS<CR><LF>
Receiver
Response
Receiver response when specifying the latitude and longitude
$>
Receiver response when querying the current setting
$>JPOS,LAT,LON
Additional
Information
200
The status of this command is also output in the JSHOW message.
Commands and Messages
JQUERY,GUIDE Command
Command
Type
General Operation and Configuration
Description
Query the receiver for its determination on whether or not it is providing suitable accuracy after both the
SBAS and GPS have been acquired (up to five minutes)
This feature takes into consideration the download status of the SBAS ionospheric map and also the
carrier phase smoothing of the unit.
Command
Format
$JQUERY,GUIDE<CR><LF>
Receiver
Response
If the receiver is ready for use with navigation, or positioning with optimum performance, it returns:
$>JQUERY,GUIDE,YES<CR><LF>
Otherwise, it returns:
$>JQUERY,GUIDE,NO<CR><LF>
Additional
Information
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JQUERY,RTKSTAT Command
Command
Type
Local Differential and RTK
Description
Perform a one-time query of the most relevant parameters affecting RTK
Command
Format
$JQUERY,RTKSTAT<CR><LF>
As an alternative you can log this as a message using the JASC,PSAT,RTKSTAT command.
Receiver
Response
$>JQUERY,RTKSTAT,MODE,TYP,AGE,SUBOPT,DIST,SYS,NUM,SNR,RSF,BSF,HAG*CC
where
Message
Component
Description
MODE
FIX,FLT,DIF,AUT,NO
TYP
DFX,ROX,CMR,RTCM3,CMR+,...
AGE
Age of differential corrections, in seconds
SUBOPT
Subscription code (see Interpreting the $JI and $JK 'Date'/Subscription Codes
to determine the meaning of the subscription code)
DIST
Distance to base in kilometers
SYS
Systems in use:
•
•
•
GLONASS: G1, G2
Galileo: E5a, E5b, E5a+b, E6
NUM
Number of satellites used by each system
SNR
Quality of each SNR path, where:
•
•
•
•
202
GPS: L1, L2, L5
A is > 20 dB
B is > 18 dB
C is > 15 dB
D is <= 15 dB
RSF
Rover slip flag (non zero if parity errors in last 5 minutes, good for detecting
jamming and TCXO issues)
BSF
Base slip flag
HAG
Horizontal accuracy guess
*CC
Checksum
Commands and Messages
Example
<CR>
Carriage return
<LF>
Line feed
$>JQUERY,RTKSTAT,FIX,ROX,1,007F,0.0,(,L1,L2,G1,G2,)(,11,9,6,6,)(,A,A,A,B,),0,0
,0.009,000
Additional
Information
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JRAIM Command
Command
Type
RAIM
Description
Specify the parameters of the RAIM scheme that affect the output of the PSAT,GBS message or query the
current setting
Command
Format
Specify the parameters of the RAIM scheme
$JRAIM,HPR,probHPR,probFALSE<CR><LF>
where:
Command
Component
Description
HPR
Horizontal Protection Radius: notification in the PSAT,GBS message that the
horizontal error has exceeded this amount will be received. The acceptable
range for this value is 1 to 10,000 m. The default is 10 m.
probHPR
Maximum allowed probability that the position computed lies outside the HPR.
The acceptable range for this value is 0.001% to 50%. The default is 5%.
probFALSE
Maximum allowed probability that there is a false alarm (that the position error
is reported outside the of the HPR, but it is really within the HPR). The
acceptable range for this value is 0.001% to 50%. The default is 1%.
Query the current setting
$JRAIM
Receiver
Response
Response to issuing command to specify RAIM scheme parameters
$>
Response to querying the current setting
$>JRAIM,HPR,probHPR,probFALSE
Example
To specify the RAIM scheme parameters as HPR = 8 m, probHPR = 2%, and probFALSE = 0.5% issue
the following command:
$JRAIM,8,2,0.5<CR><LF>
If you then query the receiver for the RAIM scheme issue the following command:
$JRAIM<CR><LF>
...and the response will be:
$>JRAIM,8.00,2.0000,0.5000
Additional
Information
204
The purpose of the probability of false alarm is to help make a decision on whether to declare a fault or
warning in an uncertain situation. The philosophy is to only issue a fault if the user is certain (to within the
probability of a false alarm) that the protection radius has been exceeded, else issue a warning.
Commands and Messages
JRAD Command Overview
This topic provides information related to the NMEA 0183 messages accepted by the receiver’s e-Dif application. The following
table provides a brief description of the commands supported by the e-Dif application for its control and operation.
Command
Description
JRAD,1
Display the current reference position in e-Dif applications only
JRAD,1,LAT,LON,HEIGHT
Use this command—a derivative of the JRAD,1,P command—when absolute positioning
is required in e-Dif applications only
JRAD,1,P
e-Dif: Record the current position as the reference with which to compute e-Dif
corrections. This would be used in relative mode as no absolute point information is
specified.
DGPS Base Station: Record the current position as the reference with which to compute
Base Station corrections in e-Dif applications only. This would be used in relative mode
as no absolute point information is specified
JRAD,2
Forces the receiver to use the new reference point (you normally use this command
following a JRAD,1 type command)
JRAD,3
Invoke the e-Dif function once the unit has started up with the e-Dif application active, or,
update the e-Dif solution (calibration) using the current position as opposed to the
reference position used by the JRAD,2 command
JRAD,7
Turn auto recalibration on or off
JRAD,9,1,1
Initialize the Base Station feature and use the previously entered point, either with
$JRAD,1,P or $JRAD,1,LAT,LON,HEIGHT, as the reference with which to compute Base
Station corrections in e-Dif applications only. Use this for both relative mode and absolute
mode.
Note: Use the JSAVE command to save changes you need to keep and wait for the $>SAVE COMPLETE response.
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JRAD,1 Command
Command
Type
e-Dif, DGPS Base Station
Description
Display the current reference position in e-Dif applications only
Command
Format
$JRAD,1<CR><LF>
Receiver
Response
$>JRAD,1,LAT,LON,HEIGHT
where:
Command
Component
Description
LAT
Latitude of the reference point in decimal degrees
LON
Longitude of the reference point in decimal degrees
HEIGHT
Ellipsoidal height of the reference point in meters
Upon startup of the receiver with the e-Dif application running—as opposed to with the SBAS application—
no reference position will be present in memory. If you attempt to query for the reference position, the
receiver’s response will be:
$>JRAD,1,FAILED,PRESENT LOCATION NOT STABLE
Example
When you issue the $JRAD,1 command the response will be similar to the following:
$>JRAD,1,51.00233513,-114.08232345,1050.212
Additional
Information
206
Commands and Messages
JRAD,1,LAT,LON,HEIGHT Command
Command
Type
e-Dif, DGPS Base Station
Description
Use this command—a derivative of the JRAD,1,P command—when absolute positioning is required in e-Dif
applications only
Command
Format
$JRAD,1,LAT,LON,HEIGHT<CR><LF>
where:
Command
Component
Description
LAT
Latitude of the reference point in decimal degrees
LON
Longitude of the reference point in decimal degrees
HEIGHT
Ellipsoidal height of the reference point in meters. Ellipsoidal height can be
calculated by adding the altitude and the geoidal separation, both available
from the GPGGA message.
Example:
$GPGGA,173309.00,5101.04028,N,11402.38289,W,2,07,1.4,
1071.0,M,- 17.8,M,6.0, 0122*48
ellipsoidal height = 1071.0 + (-17.8) = 1053.2 meters
Both latitude and longitude must be entered as decimal degrees. The receiver will not accept the command
if there are no decimal places.
Receiver
Response
$>JRAD,LAT,LON,HEIGHT
Additional
Information
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JRAD,1,P Command
Command
Type
e-Dif, DGPS Base Station
Description
e-Dif: Record the current position as the reference with which to compute e-Dif corrections. This would be
used in relative mode as no absolute point information is specified.
DGPS Base Station: Record the current position as the reference with which to compute Base Station
corrections in e-Dif applications only. This would be used in relative mode as no absolute point information
is specified
Command
Format
$JRAD,1,P<CR><LF>
Receiver
Response
$>JRAD,1,OK
Additional
Information
208
Commands and Messages
JRAD,2 Command
Command
Type
e-Dif
Description
Forces the receiver to use the new reference point
You normally use this command following a JRAD,1 type command.
Command
Format
$JRAD,2<CR><LF>
Receiver
Response
$>JRAD,2,OK
Additional
Information
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Hemisphere GPS Technical Reference v1.02
JRAD,3 Command
Command
Type
e-Dif
Description
This command has two primary purposes.
•
To invoke the e-Dif function once the unit has started up with the e-Dif application active
•
To update the e-Dif solution (calibration) using the current position as opposed to the reference
position used by the JRAD,2 command
Command
Format
$JRAD,3<CR><LF>
Receiver
Response
If the receiver has tracked enough satellites for a long enough period before you issue this command, it will
respond with the following. (The tracking period can be from 3 to 10 minutes and is used for modeling
errors going forward.
$>JRAD,3,OK<CR><LF>
If the e-Dif algorithms do not find sufficient data, the receiver responds with:
$>JRAD,3,FAILED,NOT ENOUGH STABLE SATELLITE TRACKS
Additional
Information
210
If you receive the failure message after a few minutes of operation, try again shortly after until you receive
the “OK” acknowledgement message. The e-Dif application begins operating as soon as the $>JRAD,3,OK
message has been received; however, a you will still need to define a reference position for e-Dif unless
relative positioning is sufficient for any needs.
Commands and Messages
JRAD,7 Command
Command
Type
e-Dif
Description
Turn auto recalibration on or off
Command
Format
$JRAD,7,n
where n = auto recalibration variable (0 = Off or 1 = On, 0 is the default)
Receiver
Response
$>
Additional
Information
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JRAD,9,1,1 Command
Command
Type
DGPS Base Station
Description
Initialize the Base Station feature and use the previously entered point, either with $JRAD,1,P or
$JRAD,1,LAT,LON,HEIGHT, as the reference with which to compute Base Station corrections in e-Dif
applications only. Use this for both relative mode and absolute mode.
Command
Format
$JRAD,9,1,1<CR><LF>
Receiver
Response
$>JRAD,9,OK
Additional
Information
The $JASC,RTCM,1 command must be sent to the receiver to start outputting standard RTCM corrections.
212
Commands and Messages
JRELAY Command
Command
Type
General Operation and Configuration
Description
Send user-defined text out of a serial port
Command
Format
$JRELAY,PORTx,MSG<CR><LF>
Receiver
Response
Example
•
'x' = destination port where the message (MSG) will be
sent
•
'MSG' = message to be sent
$>
Command
$JRELAY,PORTA,HELLO\nTHERE\n<CR><LF>
Response
HELLO
THERE
$>
Additional
Information
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JRESET Command
Command
Type
General Operation and Configuration
Description
Reset the receiver to its default operating parameters by:
Command
Format
•
Turning off outputs on all ports
•
Saving the configuration
•
Setting the configuration to its defaults (in following table)
Configuration
Setting
Elev Mask
5
Residual limit
10
Alt aiding
None
Age of Diff
45 minutes
Air mode
Auto
Diff type
Default for app
NMEA precision
5 decimals
COG smoothing
None
speed smoothing
None
WAAS
UERE thresholds
$JRESET[,X]<CR><LF>
where ',X' is an optional field:
•
When set to ALL does everything $JRESET does, plus it clears almanacs
•
When set to BOOT does everything $JRESET,ALL does, plus clears use of the real-time clock at
startup, clears use of backed-up ephemeris and almanacs, and reboots the receiver when done
Receiver
Response
$JRESET
$> Saving Configuration. Please Wait...
$>
$> Save Complete
Additional
Information
CAUTION: $JRESET clears all parameters. For the V101 Series and the LV101 you will have to issue the
$JATT, FLIPBRD,YES command to properly redefine the circuitry orientation inside the product once the
receiver has reset. Failure to do so will cause radical heading behavior.
214
Commands and Messages
JRTK Command Overview
The JRTK commands are used to define or query RTK settings.
Command
Description
JRTK,1
Show the receiver’s reference position (can issue command to base station or rover)
JRTK,1,LAT,LON,HEIGHT
Set the receiver’s reference position to the coordinates you enter (can issue command to
base station or rover)
JRTK,1,P
Set the receiver’s reference coordinates to the current calculated position if you do not
have known coordinates for your antenna location (can issue command to base station or
rover)
JRTK,5
Show the base station’s transmission status for RTK applications (can issue command to
base station)
JRTK,5,Transmit
Suspend or resume the transmission of RTK (can issue command to base station)
JRTK,6
Display the progress of the base station (can issue command to base station)
JRTK,12
Disable or enable the receiver to go into fixed integer mode (RTK) vs. float mode (L-Dif) can issue command to rover
JRTK,17
Display the transmitted latitude, longitude, and height of the base station (can issue
command to base station or rover)
JRTK,18
Display the distance from the rover to the base station, in meters (can issue command to
rover)
JRTK,28
Set the base station ID transmitted in ROX/DFX/CMR/RTCM3 messages (can issue
command to base station)
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JRTK,1 Command
Command
Type
Local Differential and RTK
Description
Show the receiver’s reference position (can issue command to base station or rover)
Command
Format
$JRTK,1<CR><LF>
Receiver
Response
$JRTK,1,LAT,LON,HEIGHT
where
Command
Component
Description
LAT
Latitude of the reference point in decimal degrees
LON
Longitude of the reference point in decimal degrees
HEIGHT
You must enter HEIGHT as ellipsoidal height in meters.
Ellipsoidal height can be calculated by adding the altitude and the geoidal
separation, both available from the GPGGA message.
Example:
$GPGGA,173309.00,5101.04028,N,11402.38289,W,2,07,1
.4,1071.0,
M,- 17.8,M,6.0, 0122*48
ellipsoidal height = 1071.0 + (-17.8) = 1053.2 meters
Example
Additional
Information
216
$>JRTK,1,33.55679117,-111.88955483,374.600
Commands and Messages
JRTK,1,LAT,LON,HEIGHT Command
Command
Type
Local Differential and RTK
Description
Set the receiver’s reference position to the coordinates you enter (can issue command to base station or
rover)
Command
Format
$JRTK,1,LAT,LON,HEIGHT<CR><LF>
where:
Comm
and
Compo
nent
Description
LAT
Latitude of the reference point in decimal degrees
LON
Longitude of the reference point in decimal degrees
HEIGH
T
You must enter HEIGHT as ellipsoidal height in meters.
Ellipsoidal height can be calculated by adding the altitude and the geoidal
separation, both available from the GPGGA message.
Example:
$GPGGA,173309.00,5101.04028,N,11402.38289,W,2,07,1.4,10
71.0,
M,- 17.8,M,6.0, 0122*48
ellipsoidal height = 1071.0 + (-17.8) = 1053.2 meters
Note: You must enter both latitude and longitude in decimal degrees; the receiver will not accept the
command if there are no decimal places.
Receiver
Response
$>
Additional
Information
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JRTK,1,P Command
Command
Type
Local Differential and RTK
Description
Set the receiver’s reference coordinates to the current calculated position if you do not have known
coordinates for your antenna location (can issue command to base station or rover)
Command
Format
$JRTK,1,P<CR><LF>
Receiver
Response
$>
Additional
Information
If you have known coordinates for your antenna location, use the JRTK,1,LAT,LON,HEIGHT command to
enter the latitude and longitude (in decimal degrees) and the ellipsoidal height (in meters).
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Commands and Messages
JRTK,5 Command
Command
Type
Local Differential and RTK
Description
Show the base station’s transmission status for RTK applications (can issue command to base station)
Command
Format
$JRTK,5<CR><LF>
Receiver
Response
If transmission status is suspended, response is as follows:
$>JRTK,6
If transmission status is not suspended, response is as follows:
$>JRTK,5,1
Additional
Information
Also see the JRTK,6 command.
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JRTK,5,Transmit Command
Command
Type
Local Differential and RTK
Description
Suspend or resume the transmission of RTK (can issue command to base station)
Command
Format
$JRTK,5,Transmit<CR><LF>
where "Transmit" is 0 (suspend) or 1 (resume)
Receiver
Response
If the transmission status is not suspended and you issue the following command to suspend:
$JRTK,5,0<CR><LF>
the response is as follows:
$>JRTK,5,OK
Similarly, if the transmission status is suspended and you issue the following command to resume:
$JRTK,5,1<CR><LF>
the response is again as follows:
$>JRTK,5,OK
Additional
Information
220
Commands and Messages
JRTK,6 Command
Command
Type
Local Differential and RTK
Description
Display the progress of the base station (can issue command to base station)
Command
Format
$JRTK,6<CR><LF>
Receiver
Response
$JRTK,6,TimeToGo,ReadyTransmit,Transmitting
where
Example
Response
Component
Description
TimeToGo
Seconds left until ready to transmit RTK
ReadyTransmit
Non zero when configured to transmit and ready to transmit RTK on at
least one port. It is a bit mask of the transmitting port, with bit 0 being port
A, bit 1 being port B and bit 2 being port C. It will be equal to "Transmitting"
unless transmission has be suspended with $JRTK,5,0.
Transmitting
Non-zero when actually transmitting RTK on at least one port. It is a bit
mask of the transmitting port, with bit 0 being port A, bit 1 being port B and
bit 2 being port C.
If the receiver is not ready to transmit:
$>JRTK,6,263,0,0
If the receiver is currently transmitting on Port B:
$>JRTK,6,0,2,2
Additional
Information
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JRTK,12 Command
Warning! Hemisphere GPS recommends that only advanced users employ this command.
Command
Type
Local Differential and RTK
Description
Disable or enable the receiver to go into fixed integer mode (RTK) vs. float mode (L-Dif) - can issue
command to rover
Note: Requires RTK rover subscription
Command
Format
$JRTK,12,x
where x is:
•
1 = Allow RTK (recommended, and the default)
•
0 = Do not allow RTK, stay in L-Dif
Receiver
Response
$>
Additional
Information
In high multipath conditions it may be desirable to prevent the rover from obtaining a fixed position. Using
$JRTK,12,0 while logging position data is useful for determining the level of multipath present.
222
Commands and Messages
JRTK,17 Command
Command
Type
Local Differential and RTK
Description
Display the transmitted latitude, longitude, and height of the base station (can issue command to base
station or rover)
Command
Format
$JRTK,17<CR><LF>
Receiver
Response
$>JRTK,17,lat,lon,height
Example
$>JRTK,17,33.55709242,-111.88916894,380.534
Additional
Information
Format is similar to JRTK,1,LAT,LON,HEIGHT
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JRTK,18 Command
Command
Type
Local Differential and RTK
Description
Display the distance from the rover to the base station, in meters (can issue command to rover)
Command
Format
$JRTK,18<CR><LF>
Receiver
Response
$>JRTK,18,d
where 'd' is the baseline distance in meters
Additional
Information
224
Commands and Messages
JRTK,28 Command
Command
Type
Local Differential and RTK
Description
Set the base station ID transmitted in ROX/DFX/CMR/RTCM3 messages (can issue command to base
station), where:
Command
Format
•
Default is 333
•
Range is 0-4095 (except for CMR which is 0-31)
Set the base station ID
$JRTK,28,BASEID<CR><LF>
where 'BASEID' is the base station ID
Query the current setting
$JRTK,28<CR><LF>
Receiver
Response
$>
Example
To set the base station ID to 123 issue the following command:
$JRTK,28,123<CR><LF>
If the base station ID is 333 and you issue the $JRTK,28<CR><LF> query the response is:
$>JRTK,28,333
Additional
Information
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JSAVE Command
Command
Type
General Operation and Configuration
Description
Send this command after making changes to the operating mode of the receiver
Command
Format
$JSAVE<CR><LF>
Receiver
Response
$> SAVING CONFIGURATION. PLEASE WAIT...
then
$> Save Complete
Additional
Information
Ensure that the receiver indicates that the save process is complete before turning the receiver off or
changing the configuration further.
No data fields are required. The receiver indicates that the configuration is being saved and indicates when
the save is complete.
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Commands and Messages
JSHOW Command
Command
Type
General Operation and Configuration
Description
Query the current operating configuration of the receiver
Command
Format
$JSHOW[,SUBSET]<CR><LF>
Receiver
Response
Use the JSHOW command without the optional 'SUBSET' field to provide a complete response from the
receiver.
Example:
$>JSHOW,BAUD,9600 (1)
$>JSHOW,BAUD,9600,OTHER (2)
$>JSHOW,BAUD,9600,PORTC (3)
$>JSHOW,ASC,GPGGA,1.0,OTHER (4)
$>JSHOW,ASC,GPVTG,1.0,OTHER (5)
$>JSHOW,ASC,GPGSV,1.0,OTHER (6)
$>JSHOW,ASC,GPGST,1.0,OTHER (7)
$>JSHOW,ASC,D1,1,OTHER (8)
$>JSHOW,DIFF,WAAS (9)
$>JSHOW,ALT,NEVER (10)
$>JSHOW,LIMIT,10.0 (11)
$>JSHOW,MASK,5 (12)
$>JSHOW,POS,51.0,-114.0 (13)
$>JSHOW,AIR,AUTO,OFF (14)
$>JSHOW,FREQ,1575.4200,250 (15)
$>JSHOW,AGE,1800 (16)
Description of responses:
Line
Description
1
Current port is set to a baud rate of 9600
2
Other port is set to a baud rate of 9600
3
Port C is set to a baud rate of 9600 (Port C is not usually connected externally on
the finished product)
4
GPGGA is output at a rate of 1 Hz from the other port
5
GPVTG is output at a rate of 1 Hz from the other port
6
GPGSV is output at a rate of 1 Hz from the other port
7
GPGST is output at a rate of 1 Hz from the other port
8
D1 is output at a rate of 1 Hz from the other
9
Current differential mode is WAAS
10
Status of the altitude aiding feature (see the JALT command for information how to
set turn altitude aiding on or off)
11
Receiver does not support this feature
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12
Elevation mask cutoff angle (in degrees)
13
Current send position used for startup, in decimal degrees
14
Current status of the AIR mode (see the JAIR command for information how to set
the AIR mode)
15
Current frequency of the L-band receiver
'AUTO' appears at the end of the query response only when the OmniSTAR
receiver is in ‘auto-tune’ mode.
16
Current maximum acceptable differential age, in seconds (see the JAGE command
for information how to set the differential age)
When you issue this command with the optional ',SUBSET' data field (without the brackets), a one-line
response is provided. The subset field may be:
•
CONF
•
GP
•
PORT
When you specify CONF for ',SUBSET' (without the brackets), an example response is:
$>JSHOW,CONF,N,0.0,10.0,5,A,60W
The following table explains the example response:
Message
Component
Description
$JSHOW,CONF
Message header
N
Indicates no altitude aiding
0.0
Indicates the aiding value, if specified (either height or PDOP threshold)
10.0
Residual limit for the $JLIMIT command
5
Elevation mask cutoff angle (in degrees)
A
AIR mode indication
60
Maximum acceptable differential age (in seconds)
W
Current differential mode, 'W' indicates WAAS mode
When you specify GP for ',SUBSET,' (without the brackets) an example response is:
$>JSHOW,GPGGA,1.0
This response will provide the JSHOW,GP message header followed by each message currently being
output through the current port and the update rate for that message.
When you specify PORT for ',SUBSET,' (without the brackets) and example response is:
$>JSHOW,THISPORT,PORTA
This response shows the port to which you are currently connected.
Example
Additional
Information
228
See "Receiver Response" section above
Commands and Messages
JSMOOTH Command
Command
Type
GPS
Description
Set the carrier smoothing interval (15 to 6000 seconds) or query the current setting
This command provides the flexibility to tune in different environments. The default for this command is 900
seconds (15 minutes) or LONG. A slight improvement in positioning performance (depending on the
multipath environment) may occur if you use either the SHORT (300 seconds) or LONG (900 seconds)
smoothing interval.
Command
Format
Set the carrier smoothing interval
To set the carrier smoothing interval to a specific number of seconds issue the following command:
$JSMOOTH,x<CR><LF>
where 'x' is one of the following:
•
Number of seconds
•
SHORT (equals 300 seconds)
• LONG (equals 900 seconds)
Query the current setting
$JSMOOTH<CR><LF>
It will return the word SHORT or LONG as well as the number of seconds used where:
Receiver
Response
•
SHORT precedes the number of seconds for any setting less than 900 seconds
•
LONG precedes the number of seconds for any setting greater than or equal to 900 seconds
Receiver response when setting the carrier smoothing interval
$>
Receiver response when querying the current carrier smoothing interval
$>JSMOOTH,x
Example
To set the carrier smoothing interval to 750 seconds issue the following command:
$JSMOOTH,750<CR><LF>
...and if you then query the receiver using $JSMOOTH the response will be:
$JSMOOTH,SHORT750
To set the carrier smoothing interval to 300 seconds (5 minutes) issue the following command:
$JSMOOTH,SHORT<CR><LF>
To set the carrier smoothing interval to 900 seconds (15 minutes) issue the following command:
$JSMOOTH,LONG<CR><LF>
Additional
Information
If you are unsure of the best value for this setting, leave it at the default setting of LONG (900 seconds).
The status of this command is also output in the JSHOW message.
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JT Command
Command
Type
General Operation and Configuration
Description
Query the receiver for its GPS engine type
Command
Format
$JT<CR><LF>
Receiver
Response
$>JT,xxxx
where xxxx indicates the GPS engine and mode:
Example
JT Command Response
(xxxx)
GPS Engine
Mode
DF2b
Eclipse
WAAS, RTK Base
DF2g
Eclipse
OmniSTAR
DF2r
Eclipse
RTK Rover
DF3g
Eclipse II
WAAS, RTK Base
DF3i
Eclipse II
e-Dif
DF3r
Eclipse II
RTK Rover
SX2a
Crescent Vector
WAAS RTK
SX2b
Crescent
Base
SX2g
Crescent
WAAS
SX2i
Crescent
e-Dif
SX2r
Crescent
Rover
When you issue the
$JT<CR><LF> command a typical response may be:
$>JT,DF2b,MX31rev=28
DF2b indicates an Eclipse receiver with WAAS and RTK Base functionality.
Note: MX31rev=28 is the processor type.
Additional
Information
230
Commands and Messages
JTAU Command Overview
The JTAU command is used to set the time constants for specific parameters for Crescent, Crescent Vector, and Eclipse
products.
Command
Description
JTAU,COG
Set the course over ground time (COG) constant and query the current setting
JTAU,SPEED
Set the speed time constant and query the current setting
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JTAU,COG Command
Note: The JATT,COGTAU command provides identical functionality but works only with Crescent Vector products.
Command
Type
GPS
Description
Set the course over ground (COG) time constant (0.00 to 3600.00 seconds) or query the current setting
This command allows you to adjust the level of responsiveness of the COG measurement provided in the
GPVTG message. The default value is 0.00 seconds of smoothing. Increasing the COG time constant
increases the level of COG smoothing.
Command
Format
Set the COG time constant
$JTAU,COG,tau<CR><LF>
where 'tau' is the new COG time constant that falls within the range of 0.00 to 200.00 seconds
The setting of this value depends upon the expected dynamics of the Crescent. If the Crescent will be in a
highly dynamic environment, this value should be set lower because the filtering window would be shorter,
resulting in a more responsive measurement. However, if the receiver will be in a largely static
environment, this value can be increased to reduce measurement noise.
Query the current setting
$JTAU,COG<CR><LF>
Receiver
Response
Receiver response when setting the COG time constant
$>
Receiver response when querying the current COG time constant
$>JTAU,COG,tau<CR><LF>
Example
To set the COG time constant as 2 seconds issue the following command:
$JTAU,COG,2<CR><LF>
Additional
Information
You can use the following formula to determine the COG time constant:
tau (in seconds) = 10 / maximum rate of change of course (in °/s)
If you are unsure about the best value for this setting, it is best to be conservative and leave it at the default
setting of 0.00 seconds.
232
Commands and Messages
JTAU,SPEED Command
Note: The JATT,SPDTAU command provides identical functionality but works only with Crescent Vector products.
Command
Type
GPS
Description
Set the speed time constant (0.00 to 3600.00 seconds) or query the current setting
This command allows you to adjust the level of responsiveness of the speed measurement provided in the
GPVTG message. The default value is 0.00 seconds of smoothing. Increasing the speed time constant
increases the level of speed measurement smoothing.
Command
Format
Set the speed time constant
$JTAU,SPEED,tau<CR><LF>
where 'tau' is the new speed time constant that falls within the range of 0.0 to 200.00 seconds
The setting of this value depends upon the expected dynamics of the receiver. If the receiver will be in a
highly dynamic environment, you should set this to a lower value, since the filtering window will be shorter,
resulting in a more responsive measurement. However, if the receiver will be in a largely static
environment, you can increase this value to reduce measurement noise.
Query the current setting
$JTAU,SPEED<CR><LF>
Receiver
Response
Receiver response when setting the speed time constant
$>
Receiver response when querying the current speed time constants
$>JTAU,SPEED,tau<CR><LF>
Example
To set the speed time constant as 4.6 seconds issue the following command:
$JTAU,SPEED,4.6<CR><LF>
Additional
Information
You can use the following formula to determine the COG time constant (Hemisphere GPS recommends
testing how the revised value works in practice):
tau (in seconds) = 10 / maximum acceleration (in m/s2)
If you are unsure of the best value for this setting, it is best to be conservative and leave it at the default
setting:
•
Crescent Vector receivers: default of 0.0 seconds
•
Non-Crescent Vector receivers: default of LONG (900 seconds)
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JWAASPRN Command
Command
Type
SBAS
Description
Change the SBAS PRNs in memory or query the receiver for current PRNs in memory
Valid PRNs include:
Command
Format
•
EGNOS: 120, 124, 126
•
GAGAN: 127
•
MSAS: 129, 137
•
WAAS: 133, 135, 138
Change the SBAS PRNs in memory
$JWAASPRN,PRN1,PRN2,PRN3<CR><LF>
where 'PRN1' and 'PRN2' specify PRNs for Crescent receivers and 'PRN3' specifies the additional PRN for
Eclipse receivers
Query the current setting
$JWAASPRN<CR><LF>
Receiver
Response
Response to issuing command to change PRNs
$>
Response to querying the current setting
$>JWAASPRN,PRN1,PRN2[,PRN3]
Example
To change the SBAS PRNs in memory for an Eclipse receiver to WAAS PRNs (133, 135, 138) issue the
following command:
$>JWAASPRN,133,135,138<CR><LF>
Additional
Information
You can specify an auto-tune mode to tune to the appropriate SBAS PRNs based on the autonomous GPS
position. To auto-tune the PRNs issue the following command:
$JWAASPRN,AUTO
If you then query the receiver for the PRNs the receiver response will show ',AUTO' at the end. For
example, if you query the receiver and the PRNs are 133,135, and 138 and autotuning is enabled the
response is as follows:
$>JWAASPRN,133,135,138,AUTO
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Commands and Messages
PCSI,0 Command (Receiver Help Query command)
Command
Type
NMEA 0183 SBX
Description
Hemisphere GPS proprietary NMEA 0183 query
Query the SBX to output a list of available proprietary PCSI commands
Command
Format
$PCSI,0<CR><LF>
Receiver
Response
$PCSI,ACK,0
$PCSI,P003-0K,012
$PCSI,0 ->HELP Msg
$PCSI,1 ->Status line A,<T>,<S>
$PCSI,2 ->Status line B,<T>
$PCSI,3 ->Dump Search,<x>
$PCSI,4 ->Wipe Search
$PCSI,5 ->Port Rate,<P0>,<P1>
$PCSI,6 ->Reset
$PCSI,7 ->RTCM Mode
Additional
Information
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PCSI,1 Command (Status Line A, Channel 0 command)
Command
Type
NMEA 0183 SBX
Description
Hemisphere GPS proprietary NMEA 0183 query
Query the SBX for a selection of parameters related to the operational status of its primary channel
Command
Format
$PCSI,1<CR><LF>
Receiver
Response
$PCSI,ACK,1
$PCSI,CS0,PXXX-Y.YYY,SN,fff.f,M,ddd,R,SS,SNR,MTP,WER,ID,H,T,G
where:
Additional
Information
Response
Component
Description
CS0
Channel 0
PXXX-Y.YYY
Resident SBX firmware version
SN
SBX receiver serial number
fff.f
Channel 0 current frequency
M
Frequency mode (A = automatic, M = manual, D = database)
ddd
MSK bit rate
R
RTCM rate mode (A = automatic, M = manual, D = database)
SS
Signal strength
SNR
Signal-to-noise ratio
MTP
Message throughput
WER
Word Error Rate - Percentage of bad 30-bit RTCM words in the last 25
words
ID
Beacon ID to which the receiver’s primary channel is tuned
H
Health of the tuned beacon [0-7]
T
$PCSI,1 status output period [0-99]
G
AGC gain in dB (0 to 48 db)
Optionally you can modify the Status Line A query to request the output of the response message once
every period at a specified output rate. It has the following format, where 'T' is the output period in seconds:
$PCSI,1,T<CR><LF>
236
Commands and Messages
The response will be:
$PCSI,ACK,1
$PCSI,CS0,PXXXY.YYY,SN,fff.f,M,ddd,R,SS,SNR,MTP,WER,ID,H,T,G
You can stop the output of the message by either of the following:
•
Cycling receiver power
• Issuing the $PCSI,1<CR><LF> query without the output period field
The response message has the same format as discussed above. In addition to this modified version of the
Status Line A command, an additional 'S' field may be placed after the 'T' field, resulting in the following
command:
$PCSI,1,T,S<CR><LF>
The 'S' field is not a variable and specifies that the output of the Status Line A message should continue
after the power has been cycled. To return the receiver to the default mode (in which message output
ceases after receiver power is cycled) send the $PCSI,1<CR><LF> query to the receiver.
You may send the $PCSI,1 query through either serial port for reporting of the full status of the primary
receiver channel. The query response is returned to the port from which you issued the command. When
querying the primary receiver channel using the secondary serial port, no interruptions in RTCM data output
will occur on the primary port provided the SBX has acquired a valid beacon.
The response is different depending on whether you are connected directly to the SBX-4 or not.
•
If connected directly (by hardware or JCONN), the response will be both an acknowledgement as
well as the full PCSI,1 message.
•
If connected through a Crescent receiver (such as the R110) you may see the full PCSI,1
message. Consider PCSI,1,1 to generate periodic output.
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PCSI,1,1 Command (Beacon Status command)
Command
Type
Beacon Receiver
Description
Obtain PCSI,CS0 beacon status data from an SBX engine when interfaced to the receiver Port D. When
you send this command through either Port A, B, or C it is automatically routed to Port D. The resulting
PCSI,CS0 message is returned to the same port from which the command was sent at the desired rate.
Command
Format
$PCSI,1,1<CR><LF>
Receiver
Response
$PCSI,CS0,Pxxx-y.yyy,SN,fff.f,M,ddd,R,SS,SNR,MTP,WER,ID,H,T,G
Example:
$PCSI,CS0,P030-0.000,19001,313.0,D,100,D,18,8,80,0,63,0,1,48
where:
Additional
Information
238
Response
Component
Description
CS0
Channel 0
PXXX-Y.YYY
Resident SBX firmware version
SN
SBX receiver serial number
fff.f
Channel 0 current frequency
M
Frequency mode (A = automatic, M = manual, D = database)
ddd
MSK bit rate
R
RTCM rate mode (A = automatic, M = manual, D = database)
SS
Signal strength
SNR
Signal-to-noise ratio
MTP
Message throughput
WER
Word Error Rate - Percentage of bad 30-bit RTCM words in the last 25
words
ID
Beacon ID to which the receiver’s primary channel is tuned
H
Health of the tuned beacon (0-7)
T
$PCSI,1 status output period (0-99)
G
AGC gain in, dB (0 to 48)
Commands and Messages
PCSI,2 Command (Status Line B, Channel 1 command)
Command
Type
NMEA 0183 SBX
Description
Hemisphere GPS proprietary NMEA 0183 query
Query the SBX to output a selection of parameters related to the operational status of its secondary channel
Command
Format
$PCSI,2<CR><LF>
Receiver
Response
$PCSI,ACK,2
$PCSI,CS1,PXXX-Y.YYY,SN,fff.f,M,ddd,R,SS,SNR,MTP,WER,ID,H,T
where:
Additional
Information
Response
Component
Description
CS1
Channel 1
PXXX-Y.YYY
Resident SBX firmware version
SN
SBX receiver serial number
fff.f
Channel 1 current frequency
M
Frequency Mode (A = automatic, M = manual, D = database)
ddd
MSK bit rate
R
RTCM rate mode (A = automatic, M = manual, D = database)
SS
Signal strength
SNR
Signal to noise ratio
MTP
Message throughput
WER
Word Error Rate - Percentage of bad 30-bit RTCM words in the last 25
words
ID
Beacon ID to which the receiver’s secondary channel is tuned
H
Health of the tuned beacon (0-7)
T
$PCSI,1 status output period (0-99)
Optionally you can modify the Status Line B query to request the output of the response message once
every period. It has the following format, where T is the output period in seconds:
$PCSI,2,T<CR><LF>
The response will:
$PCSI,ACK,2
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$PCSI,CS0,PXXX-Y.YYY,SN,fff.f,M,ddd,R,SS,SNR,MTP,WER,ID,H,T
The response message has the same format as discussed above. The Status Line B message output
cannot be set to remain active after the power of the SBX has been cycled.
The $PCSI,2 query may be sent through the either serial port for reporting of the full status of the secondary
receiver channel. The response to the query is returned to the port from which the command was issued.
When querying the secondary receiver channel using the secondary serial port, no interruptions in RTCM
data output will occur on the primary port provided that SBX has acquired a valid beacon.
240
Commands and Messages
PCSI,3,1 Command (Receiver Search Dump command)
Command
Type
NMEA 0183 SBX
Description
Hemisphere GPS proprietary NMEA 0183 query
Query the SBX to output the search information used for beacon selection in Automatic Beacon Search
mode. The output has three frequencies per line.
Command
Format
$PCSI,3,1<CR><LF>
Receiver
Response
$PCSI,ACK,3,1
$PCSI,tag1,freq1,ID1,chan1,snr1,ss1,tag2,freq2,ID2,chan2,snr2,ss2,
tag3,freq3,ID3,chan3,snr3,ss3
where:
Example
Response Component
Description
tag
Channel number with a range of 1 to 84
freq
Channel frequency (kHz * 10)
ID
Beacon ID
chan
Channel information
snr
SNR (dB)
ss
Signal Strength (dBuV/m)
$PCSI,ACK,3,1
$PCSI,01,2835,209,0E,00,-0009,02,2840,339,0E,00,-0012,03,2845,006,0E,00,0009
$PCSI,04,2850,342,0E,00,-0010,05,2855,547,0E,00,-0005,06,2860,109,0E,00,-0011
$PCSI,07,2865,188,0E,00,-0007,08,2870,272,0E,00,-0004,09,2875,682,0E,00,-0006
$PCSI,10,2880,645,0E,00,-0007,11,2885,256,0E,00,-0009,12,2890,000,06,00,-0012
$PCSI,13,2895,132,0E,00,-0009,14,2900,281,0E,00,-0010,15,2905,634,0E,00,-0008
$PCSI,16,2910,172,0E,00,-0007,17,2915,006,0E,00,-0009,18,2920,546,0E,00,-0014
$PCSI,19,2925,358,0E,00,-0008,20,2930,479,0E,00,-0009,21,2935,358,0E,00,-0011
$PCSI,22,2940,853,0E,00,-0005,23,2945,588,0E,00,-0015,24,2950,210,0E,00,-0011
$PCSI,25,2955,000,06,00,-0011,26,2960,663,0E,00,-0010,27,2965,596,0E,00,-0009
$PCSI,28,2970,000,06,00,-0009,29,2975,917,0E,00,-0009,30,2980,000,06,00,-0016
$PCSI,31,2985,343,0E,00,-0013,32,2990,546,0E,00,-0010,33,2995,546,0E,00,-0010
$PCSI,34,3000,172,0E,00,-0014,35,3005,006,0E,00,-0011,36,3010,1006,0E,00,-0009
$PCSI,37,3015,006,0E,00,-0015,38,3020,300,0E,00,-0013,39,3025,277,0E,00,-0100
$PCSI,40,3030,479,0E,00,-0010,41,3035,006,0E,00,-0012,42,3040,050,0E,00,-0008
$PCSI,43,3045,000,06,00,-0014,44,3050,172,0E,00,-0013,45,3055,000,06,00,-0011
$PCSI,46,3060,000,06,00,-0011,47,3065,000,06,00,-0014,48,3070,000,06,00,-0010
$PCSI,49,3075,000,06,00,-0012,50,3080,006,0E,00,-0015,51,3085,000,06,00,-0015
$PCSI,52,3090,300,0E,00,-0007,53,3095,000,06,00,-0013,54,3100,000,06,00,-0013
$PCSI,55,3105,000,06,00,-0012,56,3110,127,0E,00,-0013,57,3115,000,06,00,-0012
$PCSI,58,3120,596,0E,00,-0012,59,3125,051,0E,00,-0009,60,3130,000,06,00,-0011
$PCSI,61,3135,213,0E,00,-0008,62,3140,000,06,00,-0011,63,3145,000,06,00,-0015
$PCSI,64,3150,302,0E,00,-0008,65,3155,000,06,00,-0009,66,3160,000,06,00,-0003
$PCSI,67,3165,000,06,00,-0013,68,3170,000,06,00,-0011,69,3175,612,0E,01,0000
$PCSI,70,3180,000,06,00,-0015,71,3185,000,06,00,-0008,72,3190,000,06,00,-0009
$PCSI,73,3195,000,06,00,0011,74,3200,1002,0E,01,-0002,75,3205,067,0E,00,-0008
$PCSI,76,3210,001,0E,00,-0008,77,3215,000,06,00,-0009,78,3220,132,0E,00,-0009
$PCSI,79,3225,000,06,00,-0010,80,3230,339,0E,00,-0013,81,3235,000,06,00,-0011
$PCSI,82,3240,000,06,00,-0010,83,3245,202,0E,00,-0007,84,3250,006,0E,00,-0002
Additional
Information
241
Hemisphere GPS Technical Reference v1.02
PCSI,3,2 Command (Ten Closest Stations command)
Command
Type
Beacon Receiver
Description
Display the ten closest beacon stations
Command
Format
$PCSI,3,2<CR><LF>
Receiver
Response
$PCSI,3,2,StationID,name,freq,status,distance,health,WER
$PCSI,3,2, ...
$PCSI,3,2, ...
$PCSI,3,2, ...
$PCSI,3,2, ...
...
where:
Example
Additional
Information
242
Response
Component
Description
StationID
Specific ID number for beacon stations (appears in the last field of the
GPGGA message)
name
Name of station and will display time/date of update for a station added
by using information from an almanac message (in the format ddmmyy>time)
freq
Frequency, in kHz (scaled by 10), on which the station is transmitting. In
the first line of the Example below, 2870 indicates 287.0 kHz.
status
0 (operational), 1 (undefined), 2 (no information), 3 (do not use)
distance
Calculated in nautical miles
health
-1 (not updated), 8 (undefined), 0-7 (valid range)
WER
-1 (not updated), 0-100 (valid range)
$PCSI,3,2,
$PCSI,3,2,
$PCSI,3,2,
$PCSI,3,2,
$PCSI,3,2,
$PCSI,3,2,
$PCSI,3,2,
$PCSI,3,2,
$PCSI,3,2,
$PCSI,3,2,
849,Polson
848,Spokane
907,Richmond
888,Whidbey Is.
887,Robinson Pt.
874,Billings
871,Appleton
908,Amphitrite Pt
886,Fort Stevens
909,Alert Bay
MT,2870,0,210,0,0,-1,-1
WA,3160,0,250,0,0,-1,-1
BC,3200,0,356,0,0,-1,-1
WA,3020,0,363,0,0,-1,-1
WA,3230,0,383,0,0,-1,-1
MT,3130,0,389,0,0,-1,-1
WA,3000,0,420,0,0,-1,-1
BC,3150,0,448,0,0,-1,-1
OR,2870,0,473,0,0,-1,-1
BC,3090,0,480,0,0,-1,-1
Commands and Messages
PCSI,3,3 Command (Station Database command)
Command
Type
Beacon Receiver
Description
Display the contents of the beacon station database
Command
Format
$PCSI,3,3<CR><LF>
Receiver
Response
$PCSI,3,3,IDref1,IDref2,StationID,name,freq,lat,long,datum,status
$PCSI,3,3, ...
$PCSI,3,3, ...
$PCSI,3,3, ...
$PCSI,3,3, ...
...
where:
Example
Response
Component
Description
IDref1
Beacon reference ID (primary)
IDref2
Beacon reference ID (secondary)
StationID
Specific ID number for beacon stations (appears in the last field of the GPGGA
message)
name
Name of station
freq
Frequency, in kHz (scaled by 10), on which the station is transmitting. In the first line of
the Example below, 2950 indicates 295.0 kHz.
lat
Scaled by 364 (+ve indicates N and -ve indicates S)
long
Longitude is scaled by 182 (+ve indicates N and -ve indicates S)
datum
1 (NAD83), 0(WGS84)
status
0 (operational), 1(undefined), 2 (no information), 3, (do not use)
$PCSI,3,3,0282,0283,0891,Level Island
$PCSI,3,3,0306,0307,0906,Sandspit
$PCSI,3,3,0278,0279,0889,Annette Is.
$PCSI,3,3,0300,0301,0909,Alert Bay
$PCSI,3,3,0302,0303,0908,Amphitrite Pt
$PCSI,3,3,0270,0271,0885,C. Mendocino
$PCSI,3,3,0272,0273,0886,Fort Stevens
$PCSI,3,3,0304,0305,0907,Richmond
$PCSI,3,3,0276,0277,0888,Whidbey Is.
...
AK,2950,20554,-24221,1,0
BC,3000,19377,-23991,1,0
AK,3230,20044,-23951,1,0
BC,3090,18412,-23099,1,0
BC,3150,17806,-22850,1,0
CA,2920,14718,-22641,1,0
OR,2870,16817,-22559,1,0
BC,3200,17903,-22407,1,0
WA,3020,17587,-22331,1,0
Additional
Information
243
Hemisphere GPS Technical Reference v1.02
Messages (All)
Binary Messages Code
This section provides the code for the binary messages that Hemisphere GPS uses.
// BinaryMsg.h
#ifndef __BinaryMsg_H__
#define __BinaryMsg_H__
#ifdef __cplusplus
extern "C" {
#endif
/*
* Copyright (c) 2006 Hemisphere GPS and CSI Wireless Inc.,
* All Rights Reserved.
*
* Use and copying of this software and preparation of derivative works
* based upon this software are permitted. Any copy of this software or
* of any derivative work must include the above copyright notice, this
* paragraph and the one after it. Any distribution of this software or
* derivative works must comply with all applicable laws.
*
* This software is made available AS IS, and COPYRIGHT OWNERS DISCLAIMS
* ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE, AND NOTWITHSTANDING ANY OTHER PROVISION CONTAINED HEREIN, ANY
* LIABILITY FOR DAMAGES RESULTING FROM THE SOFTWARE OR ITS USE IS
* EXPRESSLY DISCLAIMED, WHETHER ARISING IN CONTRACT, TORT (INCLUDING
* NEGLIGENCE) OR STRICT LIABILITY, EVEN IF COPYRIGHT OWNERS ARE ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGES.
*/
#if defined(WIN32) || (__ARMCC_VERSION >= 300441)
#pragma pack(push)
#pragma pack(4)
#endif
/****************************************************/
/* SBinaryMsgHeader
*/
/****************************************************/
typedef struct
{
char
m_strSOH[4];
/* start of header ($BIN)
*/
unsigned short m_byBlockID;
/* ID of message (1,2,99,98,97,96,95,94,93 or 80 ) */
unsigned short m_wDataLength;
/* 52 16,304,68,28,300,128,96,56, or 40 */
} SBinaryMsgHeader;
typedef struct
{
unsigned long
ulDwordPreamble;
/* 0x4E494224 = $BIN */
unsigned long
ulDwordInfo;
/*
0x00340001 or 0x00100002 or 0x01300063 */
} SBinaryMsgHeaderDW;
/* or 0x00440062 or 0x001C0061 or 0x012C0060 */
/* or 0x0080005F or 0x0060005E or 0x0038005D */
/* or 0x00280050 */
#define BIN_MSG_PREAMBLE
0x4E494224 /* $BIN = 0x4E494224 */
#define BIN_MSG_HEAD_TYPE1 0x00340001 /* 52 = 0x34 */
#define BIN_MSG_HEAD_TYPE2 0x00100002 /* 16 = 0x10 */
#define BIN_MSG_HEAD_TYPE99 0x01300063 /* 99 = 0x63, 304 = 0x130 */
#define BIN_MSG_HEAD_TYPE102 0x01580066 /* 102 = 0x66, 344 = 0x158 */
#define BIN_MSG_HEAD_TYPE101 0x01C00065 /* 101 = 0x65, 448 = 0x1C0 */
#define BIN_MSG_HEAD_TYPE100 0x01040064 /* 100 = 0x64, 260 = 0x104 */
#define BIN_MSG_HEAD_TYPE98 0x00440062 /* 98 = 0x62, 68 = 0x44 */
#define BIN_MSG_HEAD_TYPE97 0x001C0061 /* 97 = 0x61, 28 = 0x1C */
#define BIN_MSG_HEAD_TYPE96 0x012C0060 /* 96 = 0x60, 300 = 0x12C */
244
Commands and Messages
#define BIN_MSG_HEAD_TYPE95 0x0080005F /* 95 = 0x5F, 128 = 0x80 */
#define BIN_MSG_HEAD_TYPE94 0x0060005E /* 94 = 0x5E, 96 = 0x60 */
#define BIN_MSG_HEAD_TYPE93 0x0038005D /* 93 = 0x5D, 56 = 0x38 */
#define BIN_MSG_HEAD_TYPE91 0x0198005B /* 91 = 0x5B, 408 = 0x198 = total size in bytes -8 -2
-2*/
#define BIN_MSG_HEAD_TYPE89 0x00500059 /* 89 = 0x59, 80 = 0x50 */
#define BIN_MSG_HEAD_TYPE80 0x00280050 /* 80 = 0x50, 40 = 0x28 */
#define BIN_MSG_HEAD_TYPE76 0x01C0004C /* 76 = 0x4C, 448 = 0x1C0 = total size in bytes -8 -2
-2*/
#define BIN_MSG_HEAD_TYPE71 0x01C00047 /* 71 = 0x47, 448 = 0x1C0 = total size in bytes -8 -2
-2*/
#define BIN_MSG_HEAD_TYPE61 0x0140003D /* 61 = 0x3D, 320 = 0x140 */
#define BIN_MSG_HEAD_TYPE62 0x0028003E /* 62 = 0x3E, 40 = 0x28 */
#define BIN_MSG_HEAD_TYPE65 0x00440041 /* 65 = 0x41, 68 = 0x44 */
#define BIN_MSG_HEAD_TYPE66 0x01600042 /* 66 = 0x42, 352 = 0x160 */
#define BIN_MSG_HEAD_TYPE69 0x012C0045 /* 69 = 0x45, 300 = 0x12C */
#define BIN_MSG_HEAD_TYPE59 0x0100003B /* 59 = 0x3B, 256 = 0x100 */ //GPS L2C
#define BIN_MSG_HEAD_TYPE10 0x0194000A /* 10 = 0xA, 404 = 0x194 = total size in bytes -8 -2
-2*/
#if defined(_RXAIF_PLOT_MESSAGES_)
#define BIN_MSG_HEAD_TYPE11
0x0064000B /* 11 = 0x0B, 100 = 0x64 = total size(112) in
bytes -8 -2 -2*/
#endif
#define BIN_MSG_CRLF
0x0A0D
/* CR LF = 0x0D, 0x0A */
#define CHANNELS_12
12
#define cBPM_SCAT_MEMSIZE 100
#if defined(_RXAIF_PLOT_MESSAGES_)
#define cBPM_AIFSCAT_MEMSIZE 16
#endif
typedef union
{
SBinaryMsgHeader
sBytes;
SBinaryMsgHeaderDW sDWord;
} SUnionMsgHeader;
/****************************************************/
/* SBinaryMsg1
*/
/****************************************************/
typedef struct
{
SUnionMsgHeader m_sHead;
unsigned char m_byAgeOfDiff;
/* age of differential, seconds (255 max)*/
unsigned char m_byNumOfSats;
/* number of satellites used (12 max)
*/
unsigned short m_wGPSWeek;
/* GPS week */
double
m_dGPSTimeOfWeek;
/* GPS tow */
double
m_dLatitude;
/* Latitude degrees, -90..90 */
double
m_dLongitude;
/* Latitude degrees, -180..180 */
float
m_fHeight;
/* (m), Altitude ellipsoid */
float
m_fVNorth;
/* Velocity north
m/s */
float
m_fVEast;
/* Velocity east
m/s */
float
m_fVUp;
/* Velocity up m/s */
float
m_fStdDevResid;
/* (m), Standard Deviation of
Residuals */
unsigned short m_wNavMode;
unsigned short m_wAgeOfDiff;
/* age of diff using 16 bits */
unsigned short m_wCheckSum;
/* sum of all bytes of the header and data */
unsigned short m_wCRLF;
/* Carriage Return Line Feed */
} SBinaryMsg1;
/* length = 8 + 52 + 2 + 2 = 64 */
/****************************************************/
/* SBinaryMsg2
*/
/****************************************************/
typedef struct
{
SUnionMsgHeader m_sHead;
unsigned long m_ulMaskSatsTracked; /* SATS Tracked, bit mapped 0..31 */
unsigned long m_ulMaskSatsUsed;
/* SATS Used, bit mapped 0..31 */
unsigned short m_wGpsUtcDiff;
/* GPS/UTC time difference (GPS minus UTC) */
245
Hemisphere GPS Technical Reference v1.02
unsigned short m_wHDOPTimes10;
unsigned short m_wVDOPTimes10;
unsigned short m_wWAASMask;
/* HDOP
(0.1 units) */
/* VDOP
(0.1 units) */
/* Bits 0-1: tracked sats, Bits 2-3:
used sats, Bits 5-9 WAAS PRN 1 minus
120, Bits 10-14 WAAS PRN 1 minus 120 */
unsigned short m_wCheckSum;
/* sum of all bytes of the header and data */
unsigned short m_wCRLF;
/* Carriage Return Line Feed */
} SBinaryMsg2;
/* length = 8 + 16 + 2 + 2 = 28 */
/****************************************************/
/* SChannelData
*/
/****************************************************/
typedef struct
{
unsigned char m_byChannel;
/* channel number */
unsigned char m_bySV;
/* satellite being tracked, 0 == not tracked */
unsigned char m_byStatus;
/* Status bits (code carrier bit frame...) */
unsigned char m_byLastSubFrame; /* last subframe processed */
unsigned char m_byEphmVFlag;
/* ephemeris valid flag */
unsigned char m_byEphmHealth;
/* ephemeris health */
unsigned char m_byAlmVFlag;
/* almanac valid flag */
unsigned char m_byAlmHealth;
/* almanac health */
char
m_chElev;
/* elevation angle */
unsigned char m_byAzimuth;
/* 1/2 the Azimuth angle */
unsigned char m_byURA;
/* User Range Error */
unsigned char m_byDum;
/* Place Holder */
unsigned short m_wCliForSNR;
/* code lock indicator for SNR divided by 32 */
short
m_nDiffCorr;
/* Differential correction * 100 */
short
m_nPosResid;
/* position residual * 10 */
short
m_nVelResid;
/* velocity residual * 10 */
short
m_nDoppHz;
/* expected doppler in HZ */
short
m_nNCOHz;
/* track from NCO in HZ */
} SChannelData; /* 24 bytes */
/****************************************************/
/* SChannelL2Data
*/
/****************************************************/
//#if defined(_DUAL_FREQ_)
typedef struct
{
unsigned char m_byChannel;
/* channel number */
unsigned char m_bySV;
/* satellite being tracked, 0 == not tracked */
unsigned char m_byL2CX;
/* Status bits for L2P (code carrier bit frame...) */
unsigned char m_byL1CX;
/* Status bits for L1P (code carrier bit frame...) */
unsigned short m_wCliForSNRL2P; /* code lock indicator for SNR divided by 32 */
unsigned short m_wCliForSNRL1P; /* code lock indicator for L1P SNR divided by 32 */
short
m_nC1_L1;
/* C1-L1 in meters * 100 */
short
m_nP2_C1;
/* P2-C1 in meters * 100 */
short
m_nP2_L1;
/* P2-L1 in meters * 100 */
short
m_nL2_L1;
/* L2-L1 in meters * 100 */
short
m_nP2_P1;
/* P2-P1 in meters * 100 */
short
m_nNCOHz;
/* track from NCO in HZ */
} SChannelL2Data; /* 20 bytes */
//#endif
/****************************************************/
/* SChannelL2CData
for USING_GPSL2CL
*/
/****************************************************/
typedef struct
{
unsigned char m_byChannel;
// channel number
unsigned char m_bySV;
// satellite being tracked, 0 == not tracked
unsigned char m_byL2CX;
// Status bits for L2P (code carrier bit frame...)
unsigned char spare1;
unsigned short m_wCliForSNRL2C; // code lock indicator for SNR divided by 32
unsigned short spare2;
short
m_nL2C_L1Ca;
//L2CL - CA code error meters * 100
short
m_nL2C_L2P;
//L2CL - L2P code error meters * 100
246
Commands and Messages
short
m_nL2_L1;
//L2CL - L1CA phase error meters * 100
short
m_nL2_L2P;
//L2CL - L2P phase error meters * 100
short
spare3;
short
m_nNCOHz;
// track from NCO in HZ
} SChannelL2CData; // 20 bytes
/****************************************************/
/* SBinaryMsg99
*/
/****************************************************/
typedef struct
{
SUnionMsgHeader m_sHead;
unsigned char m_byNavMode;
/* Nav Mode FIX_NO, FIX_2D, FIX_3D (high bit
=has_diff) */
char
m_cUTCTimeDiff;
/* whole Seconds between UTC and GPS
*/
unsigned short m_wGPSWeek;
/* GPS week */
double
m_dGPSTimeOfWeek;
/* GPS tow */
SChannelData
m_asChannelData[CHANNELS_12]; /* channel data */
short
m_nClockErrAtL1;
/* clock error at L1, Hz */
unsigned short m_wSpare;
/* spare */
unsigned short m_wCheckSum;
/* sum of all bytes of the header and data */
unsigned short m_wCRLF;
/* Carriage Return Line Feed */
} SBinaryMsg99;
/* length = 8 + 304 + 2 + 2 = 316 */
#define CHANNELS_SBAS_E
3
/****************************************************/
/* SBinaryMsg89 * Supports 3 SBAS Satellites
*/
/****************************************************/
typedef struct
{
SUnionMsgHeader m_sHead;
long
m_lGPSSecOfWeek;
/* GPS tow integer sec */
unsigned char m_byMaskSBASTracked; /* SBAS Sats Tracked, bit mapped 0..3 */
unsigned char m_byMaskSBASUSED;
/* SBAS Sats Used, bit mapped 0..3 */
unsigned short m_wSpare;
/* spare */
SChannelData
m_asChannelData[CHANNELS_SBAS_E]; /* SBAS channel data */
unsigned short m_wCheckSum;
/* sum of all bytes of the header and data */
unsigned short m_wCRLF;
/* Carriage Return Line Feed */
} SBinaryMsg89;
/* length = 8 + 80 + 2 + 2 = 92 */
/****************************************************/
/* SBinaryMsg100
*/
/****************************************************/
//#if defined(_DUAL_FREQ_)
typedef struct
{
SUnionMsgHeader m_sHead;
unsigned char m_byNavMode;
/* Nav Mode FIX_NO, FIX_2D, FIX_3D (high bit
=has_diff) */
char
m_cUTCTimeDiff;
/* whole Seconds between UTC and GPS
*/
unsigned short m_wGPSWeek;
/* GPS week */
unsigned long m_ulMaskSatsUsedL2P; /* L2P SATS Used, bit mapped 0..31 */
double
m_dGPSTimeOfWeek;
/* GPS tow */
unsigned long m_ulMaskSatsUsedL1P; /* L1P SATS Used, bit mapped 0..31 */
SChannelL2Data m_asChannelData[CHANNELS_12]; /* channel data */
unsigned short m_wCheckSum;
/* sum of all bytes of the header and data */
unsigned short m_wCRLF;
/* Carriage Return Line Feed */
} SBinaryMsg100;
/* length = 8 + 260 + 2 + 2 = 272 */
//#endif
/****************************************************/
/* SBinaryMsg59
for USING_GPSL2CL
*/
/****************************************************/
typedef struct
{
SUnionMsgHeader m_sHead;
unsigned char m_byNavMode;
/* Nav Mode FIX_NO, FIX_2D, FIX_3D (high bit
=has_diff) */ //1 byte
247
Hemisphere GPS Technical Reference v1.02
char
m_cUTCTimeDiff;
//1 byte
unsigned short m_wGPSWeek;
/* whole Seconds between UTC and GPS
*/
/* GPS week */
//2 bytes
unsigned long m_ulMaskSatsUsedL2P; /* L2P SATS Used, bit mapped 0..31 */
//4 bytes
double
m_dGPSTimeOfWeek;
/* GPS tow */
//8 bytes
SChannelL2CData m_asChannelData[CHANNELS_12]; /* channel data */
//20*12 bytes
unsigned short m_wCheckSum;
/* sum of all bytes of the header and data */
unsigned short m_wCRLF;
/* Carriage Return Line Feed */
} SBinaryMsg59;
/* length = 8 + 260 + 2 + 2 = 272 */
/****************************************************/
/* SSVAlmanData
*/
/****************************************************/
typedef struct
{
short
m_nDoppHz;
/* doppler in HZ for stationary receiver */
unsigned char m_byCountUpdate; /* count of almanac updates */
unsigned char m_bySVindex;
/* 0 through 31 (groups of 8)*/
unsigned char m_byAlmVFlag;
/* almanac valid flag */
unsigned char m_byAlmHealth;
/* almanac health */
char
m_chElev;
/* elevation angle */
unsigned char m_byAzimuth;
/* 1/2 the Azimuth angle */
} SSVAlmanData; /* 8 bytes */
/****************************************************/
/* SBinaryMsg98
*/
/****************************************************/
typedef struct
{
SUnionMsgHeader m_sHead;
SSVAlmanData
m_asAlmanData[8];
/* SV data, 8 at a time */
unsigned char m_byLastAlman;
/* last almanac processed */
unsigned char m_byIonoUTCVFlag;
/* iono UTC flag */
unsigned short m_wSpare;
/* spare */
unsigned short m_wCheckSum;
/* sum of all bytes of the header and data */
unsigned short m_wCRLF;
/* Carriage Return Line Feed */
} SBinaryMsg98;
/* length = 8 + (64+1+1+2) + 2 + 2 = 80 */
/****************************************************/
/* SBinaryMsg97
*/
/****************************************************/
typedef struct
{
SUnionMsgHeader m_sHead;
unsigned long m_ulCPUFactor;
/* CPU utilization Factor (%=multby 450e-6) */
unsigned short m_wMissedSubFrame;
/* missed subframes */
unsigned short m_wMaxSubFramePend; /* max subframe pending */
unsigned short m_wMissedAccum;
/* missed accumulations */
unsigned short m_wMissedMeas;
/* missed measurements */
unsigned long m_ulSpare1;
/* spare 1 (zero)*/
unsigned long m_ulSpare2;
/* spare 2 (zero)*/
unsigned long m_ulSpare3;
/* spare 3 (zero)*/
unsigned short m_wSpare4;
/* spare 4 (zero)*/
unsigned short m_wSpare5;
/* spare 5 (zero)*/
unsigned short m_wCheckSum;
/* sum of all bytes of the headerand data */
unsigned short m_wCRLF;
/* Carriage Return Line Feed */
} SBinaryMsg97;
/* length = 8 + (28) + 2 + 2 = 40 */
/****************************************************/
/* SObservations
*/
/****************************************************/
typedef struct
{
unsigned long
m_ulCS_TT_SNR_PRN; /* Bits 0-7 PRN (PRN is 0 if no data) */
/* Bits 8-15 SNR_value
248
Commands and Messages
unsigned long
m_ulDoppler_FL;
SNR = 10.0*log10( 0.8192*SNR_value) */
/* Bits 16-23 Phase Track Time in units
of 1/10 second (range = 0 to 25.5
seconds (see next word) */
/* Bits 24-31 Cycle Slip Counter
Increments by 1 every cycle slip
with natural roll over after 255 */
/* Bit 0: 1 if Valid Phase, 0 otherwise
Bit 1: 1 if Track Time > 25.5 sec,
0 otherwise
Bits 2-3: unused
Bits 4-32: Signed (two's compliment)
doppler in units of m/sec x 4096.
(i.e., LSB = 1/4096). Range =
+/- 32768 m/sec. Computed as
phase change over 1/10 sec. */
/* pseudo ranges (m) */
/* phase (m) L1 wave len = 0.190293672798365*/
double
m_dPseudoRange;
double
m_dPhase;
} SObservations; /* 24 bytes */
/****************************************************/
/* SBinaryMsg96
*/
/****************************************************/
typedef struct
{
SUnionMsgHeader m_sHead;
unsigned short
m_wSpare1;
/* spare 1 (zero)*/
unsigned short
m_wWeek;
/* GPS Week Number */
double
m_dTow;
/* Predicted GPS Time in seconds */
SObservations
m_asObvs[CHANNELS_12];/* 12 sets of observations */
unsigned short
m_wCheckSum;
/* sum of all bytes of the header and data */
unsigned short
m_wCRLF;
/* Carriage Return Line Feed */
} SBinaryMsg96;
/* length = 8 + (300) + 2 + 2 = 312 */
/****************************************************/
/* SBinaryMsg95
*/
/****************************************************/
/* sent only upon command or when values change */
typedef struct
{
SUnionMsgHeader m_sHead;
unsigned short
m_wSV;
/* The satellite to which this data belongs. */
unsigned short
m_wSpare1;
/* spare 1 (chan number (as zero 9/1/2004)*/
unsigned long
m_TOW6SecOfWeek;
/* time at which this arrived (LSB = 6sec) */
unsigned long
m_SF1words[10];
/* Unparsed SF 1 message words. */
unsigned long
m_SF2words[10];
/* Unparsed SF 2 message words. */
unsigned long
m_SF3words[10];
/* Unparsed SF 3 message words. */
/* Each of the subframe words contains
one 30-bit GPS word in the lower
30 bits, The upper two bits are ignored
Bits are placed in the words from left to
right as they are received */
unsigned short
m_wCheckSum;
/* sum of all bytes of the header and data */
unsigned short
m_wCRLF;
/* Carriage Return Line Feed */
} SBinaryMsg95;
/* length = 8 + (128) + 2 + 2 = 140 */
/****************************************************/
/* SBinaryMsg94
*/
/****************************************************/
/* sent only upon command or when values change */
typedef struct
{
SUnionMsgHeader m_sHead;
/* Iono parameters. */
double
m_a0,m_a1,m_a2,m_a3; /* AFCRL alpha parameters. */
double
m_b0,m_b1,m_b2,m_b3; /* AFCRL beta parameters. */
/* UTC conversion parameters. */
double
m_A0,m_A1;
/* Coeffs for determining UTC time. */
249
Hemisphere GPS Technical Reference v1.02
unsigned
unsigned
unsigned
unsigned
long
short
short
short
m_tot;
m_wnt;
m_wnlsf;
m_dn;
/*
/*
/*
/*
Reference time for A0 & A1, sec of GPS week. */
Current UTC reference week number. */
Week number when dtlsf becomes effective. */
Day of week (1-7) when dtlsf becomes effective.
*/
short
m_dtls;
/* Cumulative past leap seconds. */
short
m_dtlsf;
/* Scheduled future leap seconds. */
unsigned short m_wSpare1;
/* spare 4 (zero)*/
unsigned short m_wCheckSum;
/* sum of all bytes of the header and data */
unsigned short m_wCRLF;
/* Carriage Return Line Feed */
} SBinaryMsg94;
/* length = 8 + (96) + 2 + 2 = 108 */
/****************************************************/
/* SBinaryMsg93
*/
/****************************************************/
/* sent only upon command or when values change */
/* WAAS ephemeris */
typedef struct
{
SUnionMsgHeader m_sHead;
unsigned short
m_wSV;
/* The satellite to which this data belongs. */
unsigned short
m_wWeek;
/* Week corresponding to m_lTOW*/
unsigned long
m_lSecOfWeekArrived; /* time at which this arrived (LSB = 1sec) */
unsigned short
m_wIODE;
unsigned short
m_wURA;
/* See 2.5.3 of Global Pos Sys Std Pos Service Spec
*/
long m_lTOW;
/* Sec of WEEK Bit 0 = 1 sec */
long m_lXG;
/* Bit 0 = 0.08 m */
long m_lYG;
/* Bit 0 = 0.08 m */
long m_lZG;
/* Bit 0 = 0.4 m */
long m_lXGDot;
/* Bit 0 = 0.000625 m/sec */
long m_lYGDot;
/* Bit 0 = 0.000625 m/sec */
long m_lZGDot;
/* Bit 0 = 0.004 m/sec */
long m_lXGDotDot;
/* Bit 0 = 0.0000125 m/sec/sec */
long m_lYGDotDot;
/* Bit 0 = 0.0000125 m/sec/sec */
long m_lZGDotDot;
/* Bit 0 = 0.0000625 m/sec/sec */
short m_nGf0;
/* Bit 0 = 2**-31 sec */
short m_nGf0Dot;
/* Bit 0 = 2**-40 sec/sec */
unsigned short
m_wCheckSum;
/* sum of all bytes of the header and data */
unsigned short
m_wCRLF;
/* Carriage Return Line Feed */
} SBinaryMsg93;
/* length = 8 + (56) + 2 + 2 = 68 */
/****************************************************/
/* SBinaryMsg80
*/
/****************************************************/
typedef struct
{
SUnionMsgHeader m_sHead;
unsigned short m_wPRN;
/* Broadcast PRN */
unsigned short m_wSpare;
/* spare (zero) */
unsigned long m_ulMsgSecOfWeek;
/* Seconds of Week For Message */
unsigned long m_aulWaasMsg[8];
/* Actual 250 bit waas message*/
unsigned short m_wCheckSum;
/* sum of all bytes of the headerand data */
unsigned short m_wCRLF;
/* Carriage Return Line Feed */
} SBinaryMsg80;
/* length = 8 + (40) + 2 + 2 = 52 */
/****************************************************/
/* SMsg91Data
*/
/****************************************************/
typedef struct
{
unsigned char bySV;
/* satellite being tracked, 0 == not tracked */
unsigned char byStatus;
/* Status bits (code carrier bit frame...) */
unsigned char byStatusSlave;
/* Status bits (code carrier bit frame...) */
unsigned char byChannel;
/* Not used */
unsigned short wEpochSlew;
unsigned short wEpochCount;
250
/* 20*_20MS_EPOCH_SLEW + _1MS_EPOCH_SLEW */
/* epoch_count */
Commands and Messages
unsigned long codeph_SNR;
SNR/4096, upper 4 bits */
unsigned long ulCarrierCycles_SNR;
lower 8 bits */
unsigned short wDCOPhaseB10_HalfWarns;
/* 0-20 = code phase (21 bits), 28-32 =
/* 0-23 = carrier cycles, 24-32 = SNR/4096
/* 0-11 = DCO phase, 12-14 = Half Cycle Warn
15 = half Cycle added */
/* potential slip count */
unsigned short m_wPotentialSlipCount;
/* SLAVE DATA */
unsigned long codeph_SNR_Slave;
/* 0-20 = code phase (21 bits), 28-32 =
SNR/4096, upper 4 bits */
unsigned long ulCarrierCycles_SNR_Slave;
/* 0-23 = carrier cycles, 24-32 = SNR/4096
lower 8 bits */
unsigned short wDCOPhaseB10_HalfWarns_Slave; /* 0-11 = DCO phase, 12-14 = Half Cycle Warn
15 = half Cycle added */
unsigned short m_wPotentialSlipCount_Slave; /* potential slip count */
} SMsg91Data; /* 32 bytes */
/****************************************************/
/* SBinaryMsg91
*/
/* Comment: Transmits data from Takemeas.c
*/
/*
debugging structure.
*/
/*
Added by bbadke 7/07/2003
*/
/****************************************************/
typedef struct
{
SUnionMsgHeader m_sHead;
/* 8 */
double
m_sec;
/* 8 bytes */
int
m_iWeek;
/* 4 bytes */
unsigned long
m_Tic;
/* 4 bytes */
long
lTicOfWeek;
/* 4 bytes */
long
lProgTic;
/* 4 bytes */
SMsg91Data
s91Data[CHANNELS_12];
/* 12*32= 384 bytes */
unsigned short
m_wCheckSum;
/* sum of all bytes of the header and data */
unsigned short
m_wCRLF;
/* Carriage Return Line Feed */
} SBinaryMsg91;
/* length = 8 + (408) + 2 + 2 = 420 */
/****************************************************/
/* SObsPacket
*/
/****************************************************/
typedef struct
{
unsigned long
m_ulCS_TT_W3_SNR;
/* Bits 0-11 (12 bits) =SNR_value
For L1 SNR = 10.0*log10( 0.1024*SNR_value)
FOR L2 SNR = 10.0*log10( 0.1164*SNR_value) */
/* Bits 12-14 (3 bits) = 3 bits of warning
for potential 1/2 cycle slips. A warning
exists if any of these bits are set. */
/* bit 15: (1 bit) 1 if Track Time > 25.5 sec,
0 otherwise */
/* Bits 16-23 (8 bits): Track Time in units
of 1/10 second (range = 0 to 25.5 seconds) */
/* Bits 24-31 (8 bits) = Cycle Slip Counter
Increments by 1 every cycle slip
with natural roll-over after 255 */
unsigned long
m_ulP7_Doppler_FL; /* Bit 0: (1 bit) 1 if Valid Phase, 0 otherwise
Bit 1-23: (23 bits) =Magnitude of doppler
LSB = 1/512 cycle/sec
Range = 0 to 16384 cycle/sec
Bit 24: sign of doppler, 1=negative, 0=pos
Bits 25-31 (7 bits) = upper 7 bits of the
23 bit carrier phase.
LSB = 64 cycles, MSB = 4096 cycles */
unsigned long
m_ulCodeAndPhase;
/* Bit 0-15 (16 bits) lower 16 bits of code
pseudorange
LSB = 1/256 meters
MSB = 128 meters
Note, the upper 19 bits are given in
251
Hemisphere GPS Technical Reference v1.02
m_aulCACodeMSBsPRN[] for CA code
Bit 16-31 lower 16 bits of the carrier phase,
7 more bits are in m_ulP7_Doppler_FL
LSB = 1/1024 cycles
MSB = 32 cycles */
} SObsPacket; /* 12 bytes , note: all zero if data not available */
/* A NOTE ON DECODING MESSAGE 76
* Notation: "code" -- is taken to mean the PseudoRange derived from code phase.
*
"phase" -- is taken to mean range derived from carrier phase.
*
This will contain cycle ambiguities.
*
* Only the lower 16 bits of L1P code, L2P code and the lower 23 bits of
* carrier phase are provided. The upper 19 bits of the L1CA code are found
* in m_aulCACodeMSBsPRN[]. The upper 19 bits of L1P or L2P must be derived
* using the fact that L1P and L2P are within 128 meters of L1CA. To
* determine L1P or L2P, use the lower 16 bits provided in the message and
* set the upper bits to that of L1CA. Then add or subtract one LSB of the
* upper bits (256 meters) so that L1P or L2P are within 1/2 LSB (128 meters)
* of the L1CA code.
*
The carrier phase is in units of cycles, rather than meters,
* and is held to within 1023 cycles of the respective code range. Only
* the lower 16+7=23 bits of carrier phase are transmitted in Msg 76.
* In order to determine the remaining bits, first convert the respective
* code range (determined above) into cycles by dividing by the carrier
* wavelength. Call this the "nominal reference phase". Next extract the 16
* and 7 bit blocks of carrier phase from Msg 76 and arrange to form the lower
* 23 bits of carrier phase. Set the upper bits (bit 23 and above) equal to
* those of the nominal reference phase. Then, similar to what was done for
* L1P and L2P, add or subtract the least significant upper bit (8192 cycles)
* so that carrier phase most closely agrees with the nominal reference phase
* (to within 4096 cycles).
*/
#define CHANNELS_12_PLUS (CHANNELS_12+2)
/* up to two SBAS satellites */
#define CHANNELS_L1_E
(CHANNELS_12+CHANNELS_SBAS_E) /* All L1 (including SBAS satellites)
*/
/****************************************************/
/* SBinaryMsg76
*/
/****************************************************/
typedef struct
{
SUnionMsgHeader m_sHead;
double
m_dTow;
/* GPS Time in seconds */
unsigned short
m_wWeek;
/* GPS Week Number */
unsigned short
m_wSpare1;
/* spare 1 (zero)*/
unsigned long
m_ulSpare2;
/* spare 2 (zero)*/
SObsPacket
m_asL2PObs[CHANNELS_12];
/* 12 sets of L2(P) observations */
SObsPacket
m_asL1CAObs[CHANNELS_L1_E]; /* 15 sets of L1(CA) observations */
unsigned long
m_aulCACodeMSBsPRN[CHANNELS_L1_E]; /* array of 15 words.
bit 7:0 (8 bits) = satellite PRN, 0
if no satellite
bit 12:8 (5 bits) = spare
bit 31:13 (19 bits) = upper 19 bits
of L1CA LSB = 256 meters
MSB = 67108864 meters */
unsigned long
m_auL1Pword[CHANNELS_12]; /* array of 12 words relating to L1(P) code.
Bit 0-15 (16 bits) lower 16 bits of the
L1P code pseudo range.
LSB = 1/256 meters
MSB = 128 meters
Bits 16-27 (12 bits) = L1P SNR_value
SNR = 10.0*log10( 0.1164*SNR_value)
If Bits 16-27 all zero, no L1P track
Bits 28-31 (4 bits) spare */
unsigned short
m_wCheckSum;
/* sum of all bytes of the header and data */
252
Commands and Messages
unsigned short
m_wCRLF;
/* Carriage Return Line Feed */
} SBinaryMsg76;
/* length = 8 + (448) + 2 + 2 = 460 */
/****************************************************/
/* SMsg71DataL1
*/
/****************************************************/
typedef struct
{
unsigned char bySV;
/* satellite being tracked, 0 == not tracked */
unsigned char byStatus;
/* Status bits (code carrier bit frame...) */
unsigned char byStatusL1P;
/* 0-8 lower 8 bits of L1P SNR/32768, if zero and
if upper two bits of m_wSNR_codeph_L1P are
zero
then L1P is not tracking */
unsigned char byStatusL2P;
/* Status bits (code carrier phase ...) */
unsigned short wEpochSlew;
/* 20*_20MS_EPOCH_SLEW + _1MS_EPOCH_SLEW */
unsigned short wEpochCount;
/* epoch_count */
unsigned long codeph_SNR;
/* 0-20 = code phase (21 bits), 28-32 = SNR/4096,
upper 4 bits */
unsigned long ulCarrierCycles_SNR;
/* 0-23 = carrier cycles, 24-32 = SNR/4096 lower
8 bits */
unsigned short wDCOPhaseB10_HalfWarns; /* 0-11 = DCO phase, 12-14 = Half Cycle Warn
15 = half Cycle added */
unsigned short m_wPotentialSlipCount;
/* potential slip count */
} SMsg71DataL1; /* 20 bytes */
/****************************************************/
/* SMsg71DataL1PL2P
*/
/****************************************************/
typedef struct
{
/* L1P and L2P Data */
//
unsigned long codeph_SNR_L1P; NOT USED YET /* 0-22 = L1 code phase (23 bits), 28-32 =
SNR/8192, upper 4 bits */
unsigned long codeph_SNR_L2P;
/* 0-22 = L2P code phase (23 bits), 28-32
= SNR/8192, upper 4 bits */
unsigned long ulCarrierCycles_SNR_L2P;
/* 0-23 = carrier cycles, 24-32 = SNR/8192
lower 8 bits */
unsigned short wDCOPhaseB10_L2P;
/* 0-11 = DCO phase, 12-15 = Spare */
unsigned short m_wSNR_codeph_L1P;
/* 0-13 = lower 14 bits of L1P code, 1415 SNR/32768 Upper 2 bits */
/* To get full L1P code, use upper bits
form L2P and adjust by
+/- 2**14 if necessary */
} SMsg71DataL1PL2P; /* 12 bytes */
/****************************************************/
/* SBinaryMsg71
*/
/* Comment: Transmits data from Takemeas.c
*/
/*
debugging structure for Dual Freq.
*/
/****************************************************/
typedef struct
{
SUnionMsgHeader m_sHead;
/* 8 */
double
m_sec;
/* 8 bytes */
int
m_iWeek;
/* 4 bytes */
unsigned long
m_Tic;
/* 4 bytes */
long
lTicOfWeek;
/* 4 bytes */
long
lProgTic;
/* 4 bytes */
SMsg71DataL1PL2P s91L2PData[CHANNELS_12];
/* 12*12 = 144 bytes */
SMsg71DataL1
s91Data[CHANNELS_12_PLUS]; /* 14*20 = 280 bytes */
unsigned short
m_wCheckSum;
/* sum of all bytes of the header and data
*/
unsigned short
m_wCRLF;
/* Carriage Return Line Feed */
} SBinaryMsg71;
/* length = 8 + (448) + 2 + 2 = 460 */
/////////////////////////////////////////////////////
// SBinaryMsg10
// Comment: Transmits scatter plot data from
253
Hemisphere GPS Technical Reference v1.02
//
buffacc.c
//
/////////////////////////////////////////////////////
enum eBIN10_TYPE {eBIN10_GPSL1CA=0,eBIN10_GPSL1P,eBIN10_GPSL2P,
eBIN10_GLONASSL1,eBIN10_GLONASSL2,eBIN10_GPSL2CL,eBIN10_GPSL5Q};
typedef struct
{
SUnionMsgHeader m_sHead;
// 8 bytes
unsigned short m_awScatterPlotDataI[cBPM_SCAT_MEMSIZE]; //100*2 = 200 bytes
unsigned short m_awScatterPlotDataQ[cBPM_SCAT_MEMSIZE]; //100*2 = 200 bytes
unsigned short m_wChannel;
unsigned short m_wSigType;
// one of eBIN10_TYPE
unsigned short
m_wCheckSum;
// sum of all bytes of the header and data
unsigned short
m_wCRLF;
// Carriage Return Line Feed
} SBinaryMsg10;
// length = 8 +200 +200 +2 +2 +2 +2 = 416
#if defined(_RXAIF_PLOT_MESSAGES_)
/////////////////////////////////////////////////////
// SBinaryMsg11
// Comment: Transmits scatter plot data for RXGNSS_AIF statistics
//
/////////////////////////////////////////////////////
enum eBIN11_TYPE {eBIN11_COUNTS=0,eBIN11_VALUES};
typedef struct
{
SUnionMsgHeader m_sHead;
// 8 bytes
unsigned short
m_awScatterPlotDataValues[cBPM_AIFSCAT_MEMSIZE];
//16*2 = 32 bytes
unsigned short
m_awScatterPlotDataCntMag[cBPM_AIFSCAT_MEMSIZE];
//16*2 = 32 bytes
unsigned short
m_awScatterPlotDataCntDCoff[cBPM_AIFSCAT_MEMSIZE]; //16*2 = 32 bytes
unsigned short
m_wChannel;
// aif_sel 0: AIF_A, 1: AIF_B, ...
unsigned short
m_wSigType;
// one of eBIN11_TYPE
unsigned short
m_wCheckSum;
// sum of all bytes of the header and data
unsigned short
m_wCRLF;
// Carriage Return Line Feed
} SBinaryMsg11;
// length = 8 +32 +32 +32 +2 +2 +2 +2 = 112
#endif
/****************************************************/
/* SGLONASSChanData
*/
/****************************************************/
typedef struct
{
unsigned char m_bySV;
/* Bit (0-6) = SV slot, 0 == not tracked
* Bit 7 = Knum flag
* = KNum+8 if bit 7 set
*/
unsigned char m_byAlm_Ephm_Flags; /* ephemeris and almanac status flags */
/* bit 0: Ephemeris available but timed out
* bit 1: Ephemeris valid
* bit 2: Ephemeris health OK
* bit 3: unused
* bit 4: Almanac available
* bit 5: Almanac health OK
* bit 6: unused
* bit 7: Satellite doesn't exist
*/
unsigned char m_byStatus_L1;
/* Status bits (code carrier bit frame...) */
unsigned char m_byStatus_L2;
/* Status bits (code carrier bit frame...) */
char
m_chElev;
/* elevation angle */
unsigned char m_byAzimuth;
/* 1/2 the Azimuth angle */
unsigned char m_byLastMessage;
/* last message processed */
unsigned char m_bySlip01;
/* cycle slip on chan 1 */
unsigned short m_wCliForSNR_L1;
/* code lock indicator for SNR divided by 32 */
unsigned short m_wCliForSNR_L2;
/* code lock indicator for SNR divided by 32 */
short
m_nDiffCorr_L1;
/* Differential correction * 100 */
short
m_nDoppHz;
/* expected doppler in HZ at glonass L1 */
short
m_nNCOHz_L1;
/* track from NCO in HZ */
254
Commands and Messages
short
m_nNCOHz_L2;
/* track from NCO in HZ */
short
m_nPosResid_1;
/* position residual 1 * 1000 */
short
m_nPosResid_2;
/* position residual 2 * 1000 */
} SGLONASSChanData; /* 24 bytes */
/****************************************************/
/* SBinaryMsg69
*/
/****************************************************/
typedef struct
{
SUnionMsgHeader
m_sHead;
long
m_lSecOfWeek;
/* tow */
unsigned short
m_wL1usedNavMask; /* mask of L1 channels used in nav solution */
unsigned short
m_wL2usedNavMask; /* mask of L2 channels used in nav solution */
SGLONASSChanData
m_asChannelData[CHANNELS_12]; /* channel data 12X24 = 288 */
unsigned short
m_wWeek;
/* week */
unsigned char
m_bySpare01;
/* spare 1 */
unsigned char
m_bySpare02;
/* spare 2 */
unsigned short
m_wCheckSum;
/* sum of all bytes of the header and data */
unsigned short
m_wCRLF;
/* Carriage Return Line Feed */
} SBinaryMsg69;
/* length = 8 + 300 + 2 + 2 = 312 */
/****************************************************/
/* SMsg61Data
*/
/****************************************************/
typedef struct
{
unsigned char bySV;
/* satellite slot 0 == not tracked */
unsigned char byStatusL1;
/* Status bits (code carrier bit frame...) */
unsigned char byStatusL2;
/* Status bits (code carrier bit frame...) */
unsigned char byL1_L2_DCO;
/* 0-3 = upper 4 bits of L1 carrier DCO Phase
* 4-7 = upper 4 bits of L2 carrier DCO Phase
*/
unsigned short wEpochSlewL1;
/* 0-9 = slew, 0 to 1000 count for ms of sec
* 10-15 = 6 bits of L1 slip count */
unsigned short wEpochCountL1;
/* 0-9 = epoch_count, 0 to 1000 count for ms of sec
* 10-15 = 6 bits of L2 slip count */
unsigned long codeph_SNR_L1;
/* 0-20 = L1 code phase (21 bits = 9+12),
* 21-32 = L1 SNR/4096 (upper 11 of 12 bits) */
unsigned long ulCarrierCycles_L1; /* 0-23 = L1 carrier cycles,
* 24-32 = L1 Carrier DCO lower 8 bits */
unsigned long codeph_SNR_L2;
/* 0-20 = L2 code phase (21 bits = 9+12),
* 21-32 = L2 SNR/4096 (upper 11 of 12 bits) */
unsigned long ulCarrierCycles_L2; /* 0-23 = L2 carrier cycles,
* 24-32 = L2 Carrier DCO lower 8 bits */
} SMsg61Data; /* 24 bytes */
/****************************************************/
/* SBinaryMsg61
*/
/* Comment: Transmits data from TakemeasGLONASS.c */
/*
debugging structure for Dual Freq.
*/
/****************************************************/
typedef struct
{
SUnionMsgHeader m_sHead;
/* 8 */
unsigned long
m_Tic;
/* 4 bytes */
unsigned long
ulSpare;
/* 4 bytes */
unsigned short
awHalfWarns[CHANNELS_12]; /* 12*2 = 24 bytes */
/* each word is
* bit 0-2 L1 Half Cycle Warn
* bit 3 = L1 half cycle added
* bit 4-6 L2 Half Cycle Warn
* bit 7 = L2 half cycle added
* 8 = LSB of 12 bit L1 SNR/4096
* 9 = LSB of 12 bit L2 SNR/4096
* bit 10-15 Ktag of the SV */
SMsg61Data
as61Data[CHANNELS_12];
/* 12*24 = 288 bytes */
unsigned short
m_wCheckSum;
/* sum of all bytes of the header and data */
255
Hemisphere GPS Technical Reference v1.02
unsigned short
m_wCRLF;
/* Carriage Return Line Feed */
} SBinaryMsg61;
/* length = 8 + (320) + 2 + 2 = 332 */
/****************************************************/
/* SBinaryMsg66 GLONASS OBS (see notes on mesage 76) */
/****************************************************/
typedef struct
{
SUnionMsgHeader m_sHead;
double
m_dTow;
/* Time in seconds */
unsigned short
m_wWeek;
/* GPS Week Number */
unsigned short
m_wSpare1;
/* spare 1 (zero)*/
unsigned long
m_ulSpare2;
/* spare 2 (zero)*/
SObsPacket
m_asL1Obs[CHANNELS_12];
/* 12 sets of L1(Glonass) observations */
SObsPacket
m_asL2Obs[CHANNELS_12];
/* 12 sets of L2(Glonass) observations */
unsigned long
m_aulL1CodeMSBsSlot[CHANNELS_12]; /* array of 12 words.
bit 7:0 (8 bits) = satellite Slot, 0
if no satellite
bit 12:8 (5 bits) = spare
bit 31:13 (19 bits) = upper 19 bits
of L1 LSB = 256 meters
MSB = 67108864 meters */
unsigned short
m_wCheckSum;
/* sum of all bytes of the header and data */
unsigned short
m_wCRLF;
/* Carriage Return Line Feed */
} SBinaryMsg66;
/* length = 8 + (352) + 2 + 2 = 364 */
/****************************************************/
/* SGLONASS_String, added for glonass strings
*/
/****************************************************/
typedef struct
{
unsigned long m_aul85Bits[3]; /* holds bits 9-85 of the GLONASS string */
/*
* bit order in message 65
*
MSB
LSB
* m_aul85Bits[0]: 85 84...........54
* m_aul85Bits[1]: 53 52...........22
* m_aul85Bits[2]: 21 20......9
*/
} SGLONASS_String;
/* 12 bytes (max of 96 bits) */
/****************************************************/
/* SBinaryMsg65, added by JL for glonass subframe immediate data + string_5 */
/****************************************************/
/* sent only upon command or when values change (not including changes in tk) */
typedef struct
{
SUnionMsgHeader m_sHead;
unsigned char
m_bySV;
/* The satellite to which this data
belongs. */
unsigned char
m_byKtag;
/* The satellite K Number + 8. */
unsigned short
m_wSpare1;
/* Spare, keeps alignment to 4 bytes */
unsigned long
m_ulTimeReceivedInSeconds;
/* time at which this arrived */
SGLONASS_String m_asStrings[5];
/* first 5 Strings of Glonass Frame (60
bytes) */
unsigned short
m_wCheckSum;
/* sum of all bytes of the header and
data */
unsigned short
m_wCRLF;
/* Carriage Return Line Feed */
} SBinaryMsg65;
/* length = 8 + (68) + 2 + 2 = 80 */
/*********************************************************************/
/* SBinaryMsg62, Glonass almanac data. Containing string
*
5 and the two string pair for each satellite after string 5.
*
String 5 contains the time reference for the glonass almanac
*
and gps-glonass time differences.
*
*********************************************************************/
typedef struct
{
256
Commands and Messages
SUnionMsgHeader
unsigned char
belongs. */
unsigned char
unsigned short
SGLONASS_String
m_sHead;
m_bySV;
m_byKtag_ch;
m_wSpare1;
m_asStrings[3];
unsigned short
m_wCheckSum;
data */
unsigned short
m_wCRLF;
} SBinaryMsg62;
#if defined(WIN32) || (__ARMCC_VERSION >= 300441)
#pragma pack(pop)
#endif
#ifdef __cplusplus
}
#endif
#endif // __BinaryMsg_H_
/* The satellite to which this data
/* Proprietary data */
/* Spare, keeps alignment to 4 bytes */
/* glonass almanac data (36 bytes)
0 & 1 = Two almanac SFs, 3= SF 5*/
/* sum of all bytes of the header and
/* Carriage Return Line Feed */
/* length = 8 + (40) + 2 + 2 = 52 */
257
Hemisphere GPS Technical Reference v1.02
Bin1 Message
Message
Type
Binary
Description
GPS position message (position and velocity data)
Command
Format to
Request
Message
$JBIN,1,R<CR><LF>
Message
Format
258
where:
•
'1' = Bin1 message
•
'R' = message rate in Hz (20, 10, 2, 1, 0, or .2)
Component
Description
Type
Bytes
Values
AgeOfDiff
Age of differential, seconds. Use
Extended AgeOfDiff first. If both = 0,
then no differential
Byte
1
0 to 255
NumOfSats
Number of satellites used in the GPS
solution
Byte
1
0 to 12
GPSWeek
GPS week associated with this
message
Unsigned
short
2
0 to 65536
GPSTimeOf
Week
GPS tow (sec) associated with this
message
Double
8
0.0 to
604800.0
Latitude
Latitude in degrees north
Double
8
-90.0 to 90.0
Longitude
Longitude in degrees East
Double
8
-180.0 to
180.0
Height
Altitude above the ellipsoid in meters
Float
4
VNorth
Velocity north in m/s
Float
4
VEast
Velocity east in n/s
Float
4
Vup
Velocity up in m/s
Float
4
StdDevResid
Standard deviation of residuals in
meters
Float
4
Positive
Commands and Messages
NavMode
Navigation mode:
0 = No fix
1 = FIX_2D
2 = FIX_3D (or FIX_3d and solving
ambiguities if rover)
3 = FIX_2D and Diff
4 = FIX_3D Diff (not solving
ambiguities if rover)
5 = RTK Search
6 = FIX_3D and Diff and RTK
solution
Unsigned
short
2
Bits 0 through
6 = Navmode
Bit 7 = Manual
mark
If bit 7 is set (left-most bit), then this
is a manual position
Extended
AgeOfDiff
Structure
Extended age of differential,
seconds. If 0, use 1 byte AgeOfDiff
listed above
typedef struct
{
SUnionMsgHeader
unsigned char
unsigned char
unsigned short
double
double
double
float
float
float
float
float
unsigned short
unsigned short
unsigned short
unsigned short
} SBinaryMsg1;
m_sHead;
m_byAgeOfDiff;
m_byNumOfSats;
m_wGPSWeek;
m_dGPSTimeOfWeek;
m_dLatitude;
m_dLongitude;
m_fHeight;
m_fVNorth;
m_fVEast;
m_fVUp;
m_fStdDevResid;
m_wNavMode;
m_wAgeOfDiff;
m_wCheckSum;
m_wCRLF;
Unsigned
short
2
0 to 65536
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
age of differential, seconds (255 max)*/
number of satellites used (12 max)
*/
GPS week */
GPS tow */
Latitude degrees, -90..90 */
Longitude degrees, -180..180 */
(m), Altitude ellipsoid */
Velocity north
m/s */
Velocity east
m/s */
Velocity up m/s */
(m), Standard Deviation of
Residuals */
/*
/*
/*
/*
age of diff using 16 bits */
sum of all bytes of the header and data */
Carriage Return Line Feed */
length = 8 + 52 + 2 + 2 = 64 */
Additional
Information
Message has a BlockID of 1 and is 52 bytes, excluding the header and epilogue
Related
Commands
JBIN
259
Hemisphere GPS Technical Reference v1.02
Bin2 Message
Message
Type
Binary
Description
GPS DOPs (Dilution of Precision)
This message contains various quantities that are related to the GPS solution.
Command
Format to
Request
Message
Message
Format
Structure
260
$JBIN,2,R<CR><LF>
where:
•
'2' = Bin2 message
•
'R' = message rate in Hz (1 or 0)
Component
Description
Type
Bytes
Values
MaskSatsTracked
Mask of satellites tracked by the GPS.
Bit 0 corresponds to the GPS satellite
with PRN 1.
Unsigned long
4
Individual bits
represent
satellites
MaskSatsUsed
Mask of satellites used in the GPS
solution. Bit 0 corresponds to the
GPS satellite with PRN 1.
Unsigned long
4
Individual bits
represent
satellites
GpsUtcDiff
Whole seconds between UTC and
GPS time (GPS minus UTC)
Unsigned short
2
Positive
HDOPTimes10
Horizontal dilution of precision scaled
by10 (0.1 units)
Unsigned short
2
Positive
VDOPTimes10
Vertical dilution of precision scaled by
10 (0.1 units)
Unsigned short
2
Positive
WAASMask
PRN and tracked or used status
masks
Unsigned short
2
See following
•
Bit 00 - Mask of satellites tracked by first WAAS satellite
•
Bit 01 - Mask of satellites tracked by second WAAS satellite
•
Bit 02 - Mask of satellites used by first WAAS satellite
•
Bit 03 - Mask of satellites used by second WAAS satellite
•
Bit 04 - Unused
•
Bits 05-09 - Value used to find PRN of first WAAS satellite (This value + 120 = PRN)
•
Bits 10-14 - Value used to find PRN of second WAAS satellite (This value + 120 = PRN)
•
Bit 15 - Unused
typedef struct
{
SUnionMsgHeader
unsigned long
unsigned long
m_sHead;
m_ulMaskSatsTracked; /* SATS Tracked, bit mapped 0..31 */
m_ulMaskSatsUsed; /* SATS Used, bit mapped 0..31 */
Commands and Messages
unsigned
unsigned
unsigned
unsigned
short
short
short
short
unsigned short
unsigned short
} SBinaryMsg2;
m_wGpsUtcDiff;
m_wHDOPTimes10;
m_wVDOPTimes10;
m_wWAASMask;
m_wCheckSum;
m_wCRLF;
/*
/*
/*
/*
GPS/UTC time difference (GPS minus UTC) */
HDOP (0.1 units) */
VDOP (0.1 units) */
Bits 0-1: tracked sats, Bits 2-3:
used sats, Bits 5-9 WAAS PRN 1 minus
120, Bits 10-14 WAAS PRN 1 minus 120 */
/* sum of all bytes of the header and data */
/* Carriage Return Line Feed */
/* length = 8 + 16 + 2 + 2 = 28 */
Additional
Information
Message has a BlockID of 2 and is 16 bytes, excluding the header and epilogue
Related
Commands
JBIN
261
Hemisphere GPS Technical Reference v1.02
Bin62 Message
Message
Type
Binary
Description
GLONASS almanac information
Command
Format to
Request
Message
$JBIN,62,R<CR><LF>
Message
Format
where:
•
'62' = Bin62 message
•
'R' = message rate in Hz (1 or 0)
Component
Description
Type
Bytes
SV
Satellite to which this data belongs
Byte
1
Ktag_ch
Proprietary data
Byte
1
Spare1
Spare, keeps alignment to 4 bytes
Unsigned short
2
Strings[3]
GLONASS almanac data (36 bytes)
SGLONASS string
36
•
•
Structure
typedef struct
{
SUnionMsgHeader
unsigned char
unsigned char
unsigned short
SGLONASS_String
unsigned short
unsigned short
} SBinaryMsg62;
Additional
Information
Related
Commands
262
JBIN
Values
0 & 1 = Two almanac SFs
3= SF 5
m_sHead;
m_bySV;
/* The satellite to which this data belongs. */
m_byKtag_ch; /* Proprietary data */
m_wSpare1;
/* Spare, keeps alignment to 4 bytes */
m_asStrings[3]; /* glonass almanac data (36 bytes)
0 & 1 = Two almanac SFs, 3= SF 5*/
m_wCheckSum; /* sum of all bytes of the header and data */
m_wCRLF;
/* Carriage Return Line Feed */
/* length = 8 + (40) + 2 + 2 = 52 */
Commands and Messages
Bin65 Message
Message
Type
Binary
Description
GLONASS ephemeris information
Command
Format to
Request
Message
$JBIN,65,R<CR><LF>
Message
Format
Structure
where:
•
'65' = Bin65 message
•
'R' = message rate in Hz (1 or 0)
Component
Description
Type
Bytes
SV
Satellite to which this data
belongs
Byte
1
Ktag
Satellite K Number + 8
Byte
1
Spare1
Spare, keeps alignment to 4
bytes
Unsigned short
2
TimeReceivedInSeconds
Time at which this arrived
Unsigned long
4
Strings[5]
First five strings of GLONASS
frame (60 bytes)
SGLONASS
string
60
typedef struct
{
SUnionMsgHeader
unsigned char
unsigned char
unsigned short
unsigned long
SGLONASS_String
unsigned short
unsigned short
} SBinaryMsg65;
Values
m_sHead;
m_bySV;
/* The satellite to which this data belongs. */
m_byKtag;
/* The satellite K Number + 8. */
m_wSpare1;
/* Spare, keeps alignment to 4 bytes */
m_ulTimeReceivedInSeconds; /* time at which this arrived */
m_asStrings[5]; /* first 5 Strings of Glonass Frame (60 bytes) */
m_wCheckSum;
/* sum of all bytes of the header and data */
m_wCRLF;
/* Carriage Return Line Feed */
/* length = 8 + (68) + 2 + 2 = 80 */
Additional
Information
Related
Commands
JBIN
263
Hemisphere GPS Technical Reference v1.02
Bin66 Message
Message
Type
Binary
Description
GLONASS L1 code and carrier phase information
Command
Format to
Request
Message
$JBIN,66,R<CR><LF>
Message
Format
Structure
where:
•
'66' = Bin66 message
•
'R' = message rate in Hz (20, 10, 2, 1, or 0)
Component
Description
Type
Tow
Time in seconds
Double
Week
GPS week number
Unsigned short
Spare1
Spare 1 (zero)
Unsigned short
Spare2
Spare 2 (zero)
Unsigned long
L1Obs[CHANNELS_12]
12 sets of L1
(GLONASS)
observations
SObsPacket
L2Obs[CHANNELS_12]
12 sets of L2
(GLONASS)
observations
SObsPacket
L1CodeMSBsSlot[CHANNELS_12]
See following
Unsigned long
•
Bits 0-7 (8 bits)
Satellite slot, 0 if no satellite
•
Bits 8-12 (5 bits)
Spare bit
•
Bits 13- 31 (19 bits)
Upper 19 bits of L1, LSB = 256 meters, MSB = 67108864 meters
typedef struct
{
SUnionMsgHeader
double
unsigned short
unsigned short
unsigned long
SObsPacket
SObsPacket
unsigned long
264
Bytes
m_sHead;
m_dTow;
/* Time in seconds */
m_wWeek;
/* GPS Week Number */
m_wSpare1;
/* spare 1 (zero)*/
m_ulSpare2;
/* spare 2 (zero)*/
m_asL1Obs[CHANNELS_12]; /* 12 sets of L1(Glonass)
observations */
m_asL2Obs[CHANNELS_12]; /* 12 sets of L2(Glonass)
observations */
m_aulL1CodeMSBsSlot[CHANNELS_12]; /* array of 12 words.
bit 7:0 (8 bits) =
satellite Slot, 0 if no
satellite
bit 12:8 (5 bits) = spare
bit 31:13 (19 bits) =
upper 19 bits of L1
Values
Commands and Messages
unsigned short
unsigned short
} SBinaryMsg66;
m_wCheckSum;
m_wCRLF;
LSB = 256 meters
MSB = 67108864 meters */
/* sum of all bytes of the header and data */
/* Carriage Return Line Feed */
/* length = 8 + (352) + 2 + 2 = 364 */
Additional
Information
Related
Commands
JBIN
265
Hemisphere GPS Technical Reference v1.02
Bin69 Message
Message
Type
Binary
Description
GLONASS L1 diagnostic information
Command
Format to
Request
Message
$JBIN,69,R<CR><LF>
Message
Format
Structure
where:
•
'69' = Bin69 message
•
'R' = message rate in Hz (1 or 0)
Component
Description
Type
SecOfWeek
Tow
Long
L1usedNavMask
Mask of L1 channels used in
nav solution
Unsigned short
L2usedNavMask
Mask of L2 channels used in
nav solution
Unsigned short
ChannelData[CHANNELS_12
]
Channel data 12X24 = 288
SGLONASSChan
Data
Week
Week
Unsigned short
Spare01
Spare 1
Unsigned char
Spare02
Spare 2
Unsigned char
266
Values
typedef struct
{
SUnionMsgHeader m_sHead;
long
m_lSecOfWeek;
/* tow */
unsigned short m_wL1usedNavMask; /* mask of L1 channels used in nav solution */
unsigned short m_wL2usedNavMask; /* mask of L2 channels used in nav solution */
SGLONASSChanData m_asChannelData[CHANNELS_12]; /* channel data 12X24 = 288 */
unsigned short m_wWeek;
/* week */
unsigned char
m_bySpare01;
/* spare 1 */
unsigned char
m_bySpare02;
/* spare 2 */
unsigned short m_wCheckSum;
/* sum of all bytes of the header and data */
unsigned short m_wCRLF;
/* Carriage Return Line Feed */
} SBinaryMsg69;
/* length = 8 + 300 + 2 + 2 = 312 */
Additional
Information
Related
Commands
Bytes
JBIN
Commands and Messages
Bin76 Message
Message
Type
Binary
Description
GPS L1/L2 code and carrier phase information
Note: "Code" means pseudorange derived from code phase. "Phase" means range derived from carrier
phase. This will contain cycle ambiguities.
Only the lower 16 bits of L1P code, L2P code and the lower 23 bits of carrier phase are provided. The
upper 19 bits of the L1CA code are found in m_aulCACodeMSBsPRN[]. The upper 19 bits of L1P or L2P
must be derived using the fact L1P and L2P are within 128 m (419.9 ft) of L1CA.
To determine L1P or L2P:
1.
Use the lower 16 bits provided in the message.
2.
Set the upper buts to that of L1CA.
3.
Add or subtract on LSB of the upper bits (256 meters (839.9 feet)) so that L1P or L2P are with in
1/2 LSB (128 m (419.9 ft))
The carrier phase is in units of cycles, rather than meters, and is held to within 1023 cycles of the
respective code range. Only the lower 16+7 = 23 bits of carrier phase are transmitted in Bin 76.
To determine the remaining bits:
Command
Format to
Request
Message
Message
Format
1.
Convert the respective code range (determined above) into cycles by dividing by the carrier
wavelength. This is the nominal reference phase.
2.
Extract the 16 and 7 bit blocks of carrier phase from bin 76 and arrange it to form the lower 23
bits of carrier phase.
3.
Set the upper bits (bit 23 and above) equal to those of the nominal reference phase
4.
Add or subtract the least significant upper bit (8192 cycles) so that carrier phase most closely
agrees with the nominal reference phase (to within 4096 cycles).
$JBIN,76,R<CR><LF>
where:
•
'76' = Bin76 message
•
'R' = message rate in Hz (20, 10, 2, 1, 0, or .2)
Component
Description
Type
Bytes
TOW
Predicted GPS time in seconds
Double
8
Week
GPS week number
Unsigned short
2
Spare1
Unsigned long
2
Spare2
Unsigned long
4
Structure array
12 x 12 =
L2PSatObs[12]
(array for next 3
L2 satellite observation data
Values
267
Hemisphere GPS Technical Reference v1.02
fields)
144
CS_TT_W3_SNR
See following
Unsigned long
4
•
Bits 0-11 (12 bits)
SNR; 10.0 X log10(0.1164xSNR_value)
•
Bits 12-14 (3 bits)
Cycle Slip Warn (warning for potential 1/2 cycle slips); a warning exists if any of these bits are set
•
Bit 15 (1 bit)
Long Track Time;1 if Track Time > 25.5 sec (0 otherwise)
•
Bits 16-23 (8 bits)
Track Time (signal tracking time in seconds); LSB = 0.1 seconds; Range = 0 to 25.5 seconds
•
Bits 24-31 (8 bits)
Cycle Slips; increments by 1 every cycle slip with natural roll-over after 255
P7_Doppler_FL
Unsigned long
See following
4
•
Bit 0 (1 bit)
Phase Valid (Boolean);1 if valid phase (0 otherwise)
•
Bits 1-23 (23 bits)
Doppler (magnitude of Doppler);LSB = 1/512 cycle/sec; Range = 0 to 16384 cycle/sec
•
Bit 24 (1 bit)
Doppler Sign (sigh of Doppler);1 = negative, 0 = positive
•
Bits 25-31 (7 bits)
Carrier Phase (High port) (Upper 7 bits of the 23 bit carrier phase): LSB = 64 cycles, MSB = 4096 cycles
CideAndPhase
Unsigned long
4
See following
•
Bits 0-15 (16 bits)
Pseudorange (lower 16 bits of code pseudorange);LSB = 1/256 meters, MSB = 128 meters
Note: For CA code, the upper 19 bits are given in L1CACodeMSBsPRN[] below
•
Bits 16-31 (16 bits)
Carrier Phase (lower 16 bits of the carrier phase); LSB = 1/1024 cycles, MSB = 32 cycles
Note: The 7 MSBs are given in P7_Doppler_FL (see preceding row in this table)
L1CASatObs[15]
L1 satellite code observation data
Structure array
15 x 12 =
(array for next 3
180
fields)
CS_TT_W3_SNR
See following
Unsigned long
4
•
Bits 0-11 (12 bits)
SNR; 10.0 X log10(0.1024xSNR_value)
•
Bits 12-14 (3 bits)
Cycle Slip Warn (warning for potential 1/2 cycle slips); a warning exists if any of these bits are set
•
Bit 15 (1 bit)
Long Track Time;1 if Track Time > 25.5 sec (0 otherwise)
•
Bits 16-23 (8 bits)
Track Time (signal tracking time in seconds); LSB = 0.1 seconds; Range = 0 to 25.5 seconds
•
Bits 24-31 (8 bits)
Cycle Slips; increments by 1 every cycle slip with natural roll-over after 255
P7_Doppler_FL
Unsigned long
See following
268
•
Bit 0 (1 bit)
Phase Valid (Boolean);1 if valid phase (0 otherwise)
•
Bits 1-23 (23 bits)
4
Commands and Messages
Doppler (magnitude of Doppler);LSB = 1/512 cycle/sec; Range = 0 to 16384 cycle/sec
•
Bit 24 (1 bit)
Doppler Sign (sigh of Doppler);1 = negative, 0 = positive
•
Bits 25-31 (7 bits)
Carrier Phase (High port) (Upper 7 bits of the 23 bit carrier phase): LSB = 64 cycles, MSB = 4096 cycles
CideAndPhase
Unsigned long
4
See following
•
Bits 0-15 (16 bits)
Pseudorange (lower 16 bits of code pseudorange);LSB = 1/256 meters, MSB = 128 meters
Note: For CA code, the upper 19 bits are given in L1CACodeMSBsPRN[] below
•
Bits 16-31 (16 bits)
Carrier Phase (lower 16 bits of the carrier phase); LSB = 1/1024 cycles, MSB = 32 cycles
Note: The 7 MSBs are given in P7_Doppler_FL (see preceding row in this table)
L1CACodeMSBs
L1CA code observation
Array of 15
15 x 4 =
PRN[15]
Unsigned long
60
•
Bits 0-7 (8 bits)
PRN (space vehicle ID);PRN = 0 if no data
•
Bits 8-12 (5 bits)
Unused
See
following
•
Bits 13-31 (19 bits)
L1CA Range (upper 19 bits of L1CA); LSB = 256 meters, MSB = 67,108,864 meters
L1PCode[12]
L1(P) code observation data
Array of 12
12 x 4 =
Unsigned long
48
See
following
•
Bits 0-15 (16 bits)
L1P Range (lower 16 bits of the L1P code pseudorange);LSB = 1/256 meters, MSB = 128 meters
•
Bits 16-27 (12 bits)
L1P SNR (L1P signal-to-noise ratio); SNR = 10.0 x log(0.1164 x SNR_value), if 0, then L1P channel not
tracked
•
Bits 28-31 (4 bits)
Unused
wCeckSum
Sum of all bytes of header and
data
wCRLF
Structure
typedef struct
{
SUnionMsgHeader
double
unsigned short
unsigned short
unsigned long
SObsPacket
SObsPacket
unsigned long
unsigned long
Carriage return line feed
Unsigned short
2
Unsigned short
2
m_sHead;
m_dTow;
/* GPS Time in seconds */
m_wWeek;
/* GPS Week Number */
m_wSpare1;
/* spare 1 (zero)*/
m_ulSpare2;
/* spare 2 (zero)*/
m_asL2PObs[CHANNELS_12];
/* 12 sets of L2(P) observations */
m_asL1CAObs[CHANNELS_L1_E]; /* 15 sets of L1(CA) observations */
m_aulCACodeMSBsPRN[CHANNELS_L1_E]; /* array of 15 words.
bit 7:0 (8 bits) = satellite
PRN, 0 if no satellite
bit 12:8 (5 bits) = spare
bit 31:13 (19 bits) = upper
19 bits of L1CA
LSB = 256 meters
MSB = 67108864 meters */
m_auL1Pword[CHANNELS_12]; /* array of 12 words relating to L1(P)
code. Bit 0-15 (16 bits) lower 16
bits of the L1P code pseudo range.
269
Hemisphere GPS Technical Reference v1.02
unsigned short
unsigned short
} SBinaryMsg76;
Additional
Information
Related
Commands
270
JBIN
m_wCheckSum;
m_wCRLF;
LSB = 1/256 meters
MSB = 128 meters
Bits 16-27 (12 bits) = L1P SNR_value
SNR = 10.0*log10( 0.1164*SNR_value)
If Bits 16-27 all zero, no L1P track
Bits 28-31 (4 bits) spare */
/* sum of all bytes of the header and data */
/* Carriage Return Line Feed */
/* length = 8 + (448) + 2 + 2 = 460 */
Commands and Messages
Bin80 Message
Message
Type
Binary
Description
SBAS data frame information
Command
Format to
Request
Message
$JBIN,80,R<CR><LF>
Message
Format
Structure
where:
•
'80' = Bin80 message
•
'R' = message rate in Hz (1 or 0)
Component
Description
Type
Bytes
PRN
Broadcast PRN
Unsigned short
2
Spare
Not used at this time
Unsigned short
2
MsgSecOfWeek
Seconds of week for message
Unsigned long
4
WaasMsg[8]
250-bit WAAS message (RTCA
DO0229). 8 unsigned longs, with
most significant bit received first.
Unsigned long
4x8
= 32
typedef struct
{
SUnionMsgHeader m_sHead;
unsigned short m_wPRN;
unsigned short m_wSpare;
unsigned long m_ulMsgSecOfWeek;
unsigned long m_aulWaasMsg[8];
unsigned short m_wCheckSum;
unsigned short m_wCRLF;
} SBinaryMsg80;
/*
/*
/*
/*
/*
/*
/*
Values
Future use
Broadcast PRN */
spare (zero) */
Seconds of Week For Message */
Actual 250 bit waas message*/
sum of all bytes of the headerand data */
Carriage Return Line Feed */
length = 8 + (40) + 2 + 2 = 52 */
Additional
Information
Message has a BlockID of 80 and is 40 bytes, excluding the header and epilogue
Related
Commands
JBIN
271
Hemisphere GPS Technical Reference v1.02
Bin89 Message
Message
Type
Binary
Description
SBAS satellite tracking information (supports three SBAS satellites)
Command
Format to
Request
Message
$JBIN,89,R<CR><LF>
Message
Format
Structure
where:
•
'89' = Bin89 message
•
'R' = message rate in Hz (1 or 0)
Component
Description
Type
GPSSecOfWeek
GPS tow integer sec
Long
MaskSBASTracked
SBAS satellites
tracked, bit mapped
0..3
Byte
MaskSBASUSED
SBAS satellites
used, bit mapped
0..3
Byte
Spare
Spare
Unsigned
short
ChannelData[CHANNELS_SBAS_E]
SBAS channel data
SChannelData
typedef struct
{
SUnionMsgHeader
long
unsigned char
unsigned char
unsigned short
SChannelData
unsigned short
unsigned short
} SBinaryMsg89;
Additional
Information
Related
Commands
272
JBIN
Bytes
Values
m_sHead;
m_lGPSSecOfWeek;
/* GPS tow integer sec */
m_byMaskSBASTracked; /* SBAS Sats Tracked, bit mapped 0..3 */
m_byMaskSBASUSED; /* SBAS Sats Used, bit mapped 0..3 */
m_wSpare;
/* spare */
m_asChannelData[CHANNELS_SBAS_E]; /* SBAS channel data */
m_wCheckSum;
/* sum of all bytes of the header and data */
m_wCRLF;
/* Carriage Return Line Feed */
/* length = 8 + 80 + 2 + 2 = 92 */
Commands and Messages
Bin93 Message
Message
Type
Binary
Description
SBAS ephemeris information
Command
Format to
Request
Message
$JBIN,93,R<CR><LF>
Message
Format
where:
•
'93' = Bin93 message
•
'R' = message rate in Hz (1 or 0)
Component
Description
Type
Bytes
SV
Satellite to which this data
belongs
Unsigned short
2
Spare
Not used at this time
Unsigned short
2
TOWSecOfWeek
Time at which this arrived (LSB
= 1 sec)
Unsigned long
4
Unsigned short
2
IODE
Structure
URA
Consult the ICD-GPS-200 for
definition in Appendix A
Unsigned short
2
TO
Bit 0 = 1 sec
Long
4
XG
Bit 0 = 0.08 m
Long
4
YG
Bit 0 = 0.08 m
Long
4
ZG
Bit 0 = 0.4 m
Long
4
XGDot
Bit 0 = 0.000625 m/sec
Long
4
YXDot
Bit 0 = 0.000625 m/sec
Long
4
ZGDot
Bit 0 = 0.004 m/sec
Long
4
XGDotDot
Bit 0 = 0.0000125 m/sec/sec
Long
4
YGDotDot
Bit 0 = 0.0000125 m/sec/sec
Long
4
ZGDotDot
Bit 0 = 0.0000625 m/sec/sec
Long
4
Gf0
Bit 0 = 2**-31 sec
Unsigned short
2
Gf0Dot
Bit 0 = 2**-40sec/sec
Unsigned short
2
typedef struct
{
SUnionMsgHeader m_sHead;
unsigned short m_wSV;
Values
Future use
/* The satellite to which this data belongs. */
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unsigned short m_wWeek;
/* Week corresponding to m_lTOW*/
unsigned long
m_lSecOfWeekArrived; /* time at which this arrived (LSB = 1sec) */
unsigned short m_wIODE;
unsigned short m_wURA;
/* See 2.5.3 of Global Pos Sys Std Pos Service Spec */
long
m_lTOW;
/* Sec of WEEK Bit 0 = 1 sec */
long
m_lXG;
/* Bit 0 = 0.08 m */
long
m_lYG;
/* Bit 0 = 0.08 m */
long
m_lZG;
/* Bit 0 = 0.4 m */
long
m_lXGDot;
/* Bit 0 = 0.000625 m/sec */
long
m_lYGDot;
/* Bit 0 = 0.000625 m/sec */
long
m_lZGDot;
/* Bit 0 = 0.004 m/sec */
long
m_lXGDotDot;
/* Bit 0 = 0.0000125 m/sec/sec */
long
m_lYGDotDot;
/* Bit 0 = 0.0000125 m/sec/sec */
long
m_lZGDotDot;
/* Bit 0 = 0.0000625 m/sec/sec */
short m_nGf0;
/* Bit 0 = 2**-31 sec */
short m_nGf0Dot;
/* Bit 0 = 2**-40 sec/sec */
unsigned short m_wCheckSum; /* sum of all bytes of the header and data */
unsigned short m_wCRLF;
/* Carriage Return Line Feed */
} SBinaryMsg93;
/* length = 8 + (56) + 2 + 2 = 68 */
Additional
Information
Message has a BlockID of 93 and is 45 bytes, excluding the header and epilogue
Related
Commands
JBIN
274
Commands and Messages
Bin94 Message
Message
Type
Binary
Description
Ionospheric and UTC conversion parameters
Command
Format to
Request
Message
$JBIN,94,R<CR><LF>
Message
Format
Structure
where:
•
'94' = Bin94 message
•
'R' = message rate in Hz (1 or 0)
Component
Description
Type
Bytes
a0, a1,a2, a3
AFCRL alpha parameters
Double
8 x 4 = 32
b0, b1,b2, b3
AFCRL beta parameters
Double
8 x 4 = 32
A0, A1
Coefficients for determining UTC
time
Double
8 x 2 = 16
tot
Reference time for A0 and A1,
second of GPS week
Unsigned long
4
wnt
Current UTC reference week
Unsigned short
2
wnlsf
Week number when dtlsf
becomes effective
Unsigned short
2
dn
Day of week (1-7) when dtlsf
becomes effective
Unsigned short
2
dtls
Cumulative past leap
Short
2
dtlsf
Scheduled future leap
Short
2
Spare
Not used at this time
Short
2
Values
Future use
typedef struct
{
SUnionMsgHeader m_sHead;
/* Iono parameters. */
double
m_a0,m_a1,m_a2,m_a3; /* AFCRL alpha parameters. */
double
m_b0,m_b1,m_b2,m_b3; /* AFCRL beta parameters. */
/* UTC conversion parameters. */
double
m_A0,m_A1;
/* Coeffs for determining UTC time. */
unsigned long m_tot;
/* Reference time for A0 & A1, sec of GPS week. */
unsigned short m_wnt;
/* Current UTC reference week number. */
unsigned short m_wnlsf;
/* Week number when dtlsf becomes effective. */
unsigned short m_dn;
/* Day of week (1-7) when dtlsf becomes effective. */
short
m_dtls;
/* Cumulative past leap seconds. */
short
m_dtlsf;
/* Scheduled future leap seconds. */
unsigned short m_wSpare1;
/* spare 4 (zero)*/
unsigned short m_wCheckSum; /* sum of all bytes of the header and data */
unsigned short m_wCRLF;
/* Carriage Return Line Feed */
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Hemisphere GPS Technical Reference v1.02
} SBinaryMsg94;
/* length = 8 + (96) + 2 + 2 =
108 */
Additional
Information
Message has a BlockID of 94 and is 96 bytes, excluding the header and epilogue
Related
Commands
JBIN
276
Commands and Messages
Bin95 Message
Message
Type
Binary
Description
GPS ephemeris information
Command
Format to
Request
Message
$JBIN,95,R<CR><LF>
Message
Format
Structure
where:
•
'95' = Bin95 message
•
'R' = message rate in Hz (1 or 0)
Component
Description
Type
Bytes
SV
Satellite to which this data
belongs
Unsigned short
2
Spare1
Not used at this time
Unsigned short
2
SecOfWeek
Time at which this arrived
(LSB = 6)
Unsigned long
4
SF1words[10]
Unparsed SF 1 message
Unsigned long
4 x 10 = 40
SF2words[10]
Unparsed SF 2 message
Unsigned long
4 x 10 = 40
SF3words[10]
Unparsed SF 3 message
Unsigned long
4 x 10 = 40
typedef struct
{
SUnionMsgHeader
unsigned short
unsigned short
unsigned long
unsigned long
unsigned long
unsigned long
unsigned short
unsigned short
} SBinaryMsg95;
m_sHead;
m_wSV;
m_wSpare1;
m_TOW6SecOfWeek;
m_SF1words[10];
m_SF2words[10];
m_SF3words[10];
m_wCheckSum;
m_wCRLF;
Values
Future use
/*
/*
/*
/*
/*
/*
/*
The satellite to which this data belongs. */
spare 1 (chan number (as zero 9/1/2004)*/
time at which this arrived (LSB = 6sec) */
Unparsed SF 1 message words. */
Unparsed SF 2 message words. */
Unparsed SF 3 message words. */
Each of the subframe words contains
one 30-bit GPS word in the lower
30 bits, The upper two bits are ignored
Bits are placed in the words from left to
right as they are received */
/* sum of all bytes of the header and data */
/* Carriage Return Line Feed */
/* length = 8 + (128) + 2 + 2 = 140 */
Additional
Information
Message has a BlockID of 95 and is 128 bytes, excluding the header and epilogue
Related
Commands
JBIN
277
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Bin96 Message
Message
Type
Binary
Description
GPS L1 code and carrier phase information
Command
Format to
Request
Message
$JBIN,96,R<CR><LF>
Message
Format
where:
•
'96' = Bin96 message
•
'R' = message rate in Hz (20, 10, 2, 1, or 0)
Component
Description
Type
Bytes
Values
Spare1
Not used at this time
Unsigned short
2
Future use
Week
GPS week number
Unsigned short
2
TOW
Predicted GPS time in
seconds
Double
8
UNICS_TT_SNR_PRN[12]
See following
Unsigned long
4
•
Bits 0-7 (8 bits)
Pseudorandom noise; PRN is 0 if no data
•
Bits 8-15 (8 bits)
Signal-to noise ratio (SNR); SNR=10.0 *log10* (0.8192*SNR)
•
Bits 16-23 (8 bits)
PhaseTrackTime (PTT); in units of 1/10 sec; range=0 to 25 sec (if greater than 25 see
UIDoppler_FL[12] below)
•
Bits 24-31 (8 bits)
CycleSlip Counter (CSC); increments by 1 every cycle with natural rollover after 255
UIDoppler_FL[12]
278
See following
Unsigned long
4
•
Bit 0 (1 bit)
Phase; Location 0; 1 if valid (0 otherwise)
•
Bit 1 (1 bit)
TrackTime; 1 if track time > 25.5 seconds (0 otherwise)
•
Bits 2-3 (2 bits)
Unused
•
Bits 4-31 (28 bits)
Doppler; Signed (two’s compliment) Doppler in units of m/sec x 4096. (i.e., LSB=1/4096),
range = +/- 32768 m/sec. Computed as phase change over 1/10 sec.
PseudoRange[12]
Pseudorange
Double
8
Phase[12]
Phase (m) L1 wave =
0.190293672798365
Double
8
Commands and Messages
Structure
typedef struct
{
SUnionMsgHeader
unsigned short
unsigned short
double
SObservations
unsigned short
unsigned short
} SBinaryMsg96;
m_sHead;
m_wSpare1;
/* spare 1 (zero)*/
m_wWeek;
/* GPS Week Number */
m_dTow;
/* Predicted GPS Time in seconds */
m_asObvs[CHANNELS_12];/* 12 sets of observations */
m_wCheckSum;
/* sum of all bytes of the header and data */
m_wCRLF;
/* Carriage Return Line Feed */
/* length = 8 + (300) + 2 + 2 = 312 */
Additional
Information
Message has a BlockID of 96 and is 300 bytes, excluding the header and epilogue
Related
Commands
JBIN
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Bin97 Message
Message
Type
Binary
Description
Processor statistics
Command
Format to
Request
Message
$JBIN,97,R<CR><LF>
Message
Format
280
where:
•
'97' = Bin97 message
•
'R' = message rate in Hz (20, 10, 2, 1, 0, or .2)
Component
Description
Type
Bytes
Values
CPUFactor
CPU utilization factor
Multiply by 450e-06 to get
percentage of spare CPU that
is available
Note: This field is only relevant
on the old SLX platforms and
Eclipse platform. It is not
relevant for the Crescent
receivers.
Unsigned long
4
Positive
MissedSubFrame
Total number of missed sub
frames in the navigation
message since power on
Unsigned short
2
Positive
MaxSubFramePnd
Max sub frames queued for
processing at any one time
Unsigned short
2
Positive
MissedAccum
Total number of missed code
accumulation measurements in
the channel tracking loop
Unsigned short
2
Positive
MissedMeas
Total number missed
pseudorange measurements
Unsigned short
2
Positive
Spare 1
Not used at this time
Unsigned long
4
Future use
Spare 2
Not used at this time
Unsigned long
4
Future use
Spare 3
Not used at this time
Unsigned long
4
Future use
Spare 4
Not used at this time
Unsigned short
2
Future use
Spare 5
Not used at this time
Unsigned short
2
Future use
Commands and Messages
Structure
typedef struct
{
SUnionMsgHeader m_sHead;
unsigned long m_ulCPUFactor;
unsigned short m_wMissedSubFrame;
unsigned short m_wMaxSubFramePend;
unsigned short m_wMissedAccum;
unsigned short m_wMissedMeas;
unsigned long m_ulSpare1;
unsigned long m_ulSpare2;
unsigned long m_ulSpare3;
unsigned short m_wSpare4;
unsigned short m_wSpare5;
unsigned short m_wCheckSum;
unsigned short m_wCRLF;
} SBinaryMsg97;
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
/*
CPU utilization Factor (%=multby 450e-6) */
missed subframes */
max subframe pending */
missed accumulations */
missed measurements */
spare 1 (zero)*/
spare 2 (zero)*/
spare 3 (zero)*/
spare 4 (zero)*/
spare 5 (zero)*/
sum of all bytes of the headerand data */
Carriage Return Line Feed */
length = 8 + (28) + 2 + 2 = 40 */
Additional
Information
Message has a BlockID of 97 and is 28 bytes, excluding the header and epilogue
Related
Commands
JBIN
281
Hemisphere GPS Technical Reference v1.02
Bin98 Message
Message
Type
Binary
Description
Satellite and almanac information
Command
Format to
Request
Message
$JBIN,98,R<CR><LF>
Message
Format
Structure
where:
•
'98' = Bin98 message
•
'R' = message rate in Hz (1 or 0)
Component
Description
Type
AlmanData[8]
SV data, 8 at a time
SSVAlmanData
LastAlman
Last almanac processed
Byte
1
0 to 31
IonoUTCVFlag
Flag that is set when
ionosphere modeling data is
extracted from the GPS sub
frame 4
Byte
1
0 = not logged
2 = valid
Spare
Not used at this time
Unsigned short
2
Future use
typedef struct
{
SUnionMsgHeader
SSVAlmanData
unsigned char
unsigned char
unsigned short
unsigned short
unsigned short
} SBinaryMsg98;
m_sHead;
m_asAlmanData[8];
m_byLastAlman;
m_byIonoUTCVFlag;
m_wSpare;
m_wCheckSum;
m_wCRLF;
/*
/*
/*
/*
/*
/*
/*
Bytes
See following
SV data, 8 at a time */
last almanac processed */
iono UTC flag */
spare */
sum of all bytes of the header and data */
Carriage Return Line Feed */
length = 8 + (64+1+1+2) + 2 + 2 = 80 */
Additional
Information
Message has a BlockID of 98 and is 68 bytes, excluding the header and epilogue
Related
Commands
JBIN
282
Values
Commands and Messages
Bin99 Message
Message
Type
Binary
Description
GPS L1 diagnostic information
Command
Format to
Request
Message
$JBIN,99,R<CR><LF>
Message
Format
where:
•
'99' = Bin99 message
•
'R' = message rate in Hz (1 or 0)
Component
Description
Type
Bytes
Values
NavMode
Navigation mode
data (lower 3 bits
hold the GPS
mode, upper bit
set if differential is
available)
Byte
1
Lower 3
bits take on
the values:
0 = time not
valid
1 = No fix
2 = 2D fix
3 = 3D fix
Upper bit
(bit 7) is 1 if
differential
is available
UTCTimeDiff
Whole seconds
between UTC and
GPS time (GPS
minus UTC)
Byte
1
Positive
GPSWeek
GPS week
associated with
this message
Unsigned short
2
0 to 65536
GPSTimeofWeek
GPS tow (sec)
associated with
this message
Double
8
0.0 to
604800.0
sChannelData[CHANNELS_12]
Channel data
SChannelData
12 x 24
= 288
ClockErrAtL1
Clock error of the
GPS clock
oscillator at L1
frequency in Hz
Short
2
-32768 to
32768
Spare
Not used at this
time
Unsigned short
2
Future use
283
Hemisphere GPS Technical Reference v1.02
Structure
typedef struct
{
SUnionMsgHeader m_sHead;
unsigned char m_byNavMode;
char
unsigned short
double
SChannelData
short
unsigned short
unsigned short
unsigned short
} SBinaryMsg99;
/* Nav Mode FIX_NO, FIX_2D, FIX_3D
(high bit =has_diff) */
m_cUTCTimeDiff;
/* whole Seconds between UTC and GPS
*/
m_wGPSWeek;
/* GPS week */
m_dGPSTimeOfWeek; /* GPS tow */
m_asChannelData[CHANNELS_12]; /* channel data */
m_nClockErrAtL1;
/* clock error at L1, Hz */
m_wSpare;
/* spare */
m_wCheckSum;
/* sum of all bytes of the header and data */
m_wCRLF;
/* Carriage Return Line Feed */
/* length = 8 + 304 + 2 + 2 = 316 */
Additional
Information
Message has a BlockID of 99 and is 304 bytes, excluding the header and epilogue
Related
Commands
JBIN
284
Commands and Messages
CRMSK Message
Message
Type
Beacon
Description
Operational status message of SBX
Command
Format to
Request
Message
$GPCRQ,MSK<CR><LF>
Message
Format
$CRMSK,fff.f,X,ddd,Y,n*CC<CR><LF>
where:
Response
Component
Description
fff.f
Frequency, in kHz (283.5 to 325)
X
Tune mode (M = manual, A = automatic)
ddd
MSK bit rate, in bps (100 or 200)
Y
MSK rate selection mode (M = manual, A = automatic)
n
Period of output of performance status message, in seconds (0 to 100);
see CRMSS
*CC
Checksum
<CR>
Carriage return
<LF>
Line feed
Additional
Information
Related
Commands
GPCRQ,MSK
285
Hemisphere GPS Technical Reference v1.02
CRMSS Message
Message
Type
Beacon
Description
Performance status message of SBX
Command
Format to
Request
Message
$GPCRQ,MSS<CR><LF>
Message
Format
$CRMSS,xx,yy,fff.f,ddd*CC<CR><LF>
where:
Response
Component
Description
xx
Signal strength, in dB μV/m
yy
Signal-to-noise ratio, in dB
fff.f
Frequency, in kHz (283.5 to 325)
ddd
MSK bit rate in bps (100 or 200)
*CC
Checksum
<CR>
Carriage return
<LF>
Line feed
Additional
Information
Related
Commands
286
GPCRQ,MSS
Commands and Messages
GLMLA Message
Message
Type
GLONASS
Description
GLONASS almanac data
Contains complete almanac data for one GLONASS satellite. Multiple sentences may be transmitted, one for
each satellite in the GLONASS constellation.
Command
Format to
Request
Message
Message
Format
$JASC,GLMLA,R[,OTHER]<CR><LF>
where
•
R = message rate (in Hz) of (1 or 0)
•
,OTHER = optional field, enacts a change on the current port when you send the command without
it (and without the brackets) and enacts a change on the other port when you send the command
with it (without the brackets)
$JASC,GLMLA,a.a,b.b,cc,d.d,ee,ffff,gg,hhhh,iiii,jjjjjj,kkkkkk,mmmmmm,
nnnnnn,ppp,qqq*hh<CR><LF>
where:
Message
Component
Description
a.a
Total number of sentences
b.b
Sentence number
cc
Satellite ID (satellite slot) number
d.d
Calendar day count within the four year period beginning with the previous leap year
ee
Generalized health of the satellite and carrier frequency number respectively
ffff
Eccentricity
gg
DOT, rate of change of the draconitic circling time
hhhh
Argument of perigee
iiii
16 MSB of system time scale correction
jjjjjj
Correction to the average value of the draconitic circling time
kkkkkk
Time of the ascension node, almanac reference time
mmmmmm
Greenwich longitude of the ascension node
nnnnnn
Correction to the average value of the inclination angle
ppp
LSB of system time scale correction
qqq
Course value of the time scale shift
287
Hemisphere GPS Technical Reference v1.02
Example
Additional
Information
Similar to the GPS message GPALM
Related
Commands
JASC,GL
288
Commands and Messages
GNSSPositionData Message
Message
Type
NMEA 2000 CAN
Description
Detailed GPS position information
The GNSSPositionData message (PGN 0x1F805/129029) has an update rate of 1 Hz and DLC of 43, 47, or
51, dependent on the NumberOfReferenceStations.
Command
Format to
Request
Message
Message is continuously output on A100 CAN port
Message
Format
The following table provides the start bit, length (bit), value type, factor, and offset for the GNSSPositionData
message.
Field Name
Start
bit
Length
(Bit)
Byte
Order
Value Type
Factor
SequenceID
0
8
Intel
Unsigned
1
PositionDate
8
16
Intel
Unsigned
1
PositionTime
24
32
Intel
Unsigned
0.0001
LatitudeLow
56
32
Intel
Unsigned
1.00E-16
LatitudeHigh
88
32
Intel
Signed
4.29E-07
LongitudeLow
120
32
Intel
Unsigned
1.00E-16
LongitudeHigh
152
32
Intel
Signed
4.29E-07
AltitudeLow
184
32
Intel
Unsigned
1.00E-6
AltitudeHigh
216
32
Intel
Signed
4294.97
TypeOfSystem
248
4
Intel
Unsigned
1
GNSSMethod
252
4
Intel
Unsigned
1
GNSSIntegrity
256
2
Intel
Unsigned
1
GNSS_Reserved1
258
6
Intel
Unsigned
1
NumberOfSVs
264
8
Intel
Unsigned
1
HDOP
272
16
Intel
Signed
0.01
PDOP
288
16
Intel
Signed
0.01
GeodalSeparation
304
32
Intel
Signed
0.01
NumberOfReferenceStations
336
8
Intel
Unsigned
1
ReferenceStationType1
344
4
Intel
Unsigned
1
ReferenceStationID1
348
12
Intel
Unsigned
1
AgeOfDGNSSCorrections1
360
16
Intel
Unsigned
0.01
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Hemisphere GPS Technical Reference v1.02
ReferenceStationType2
376
4
Intel
Unsigned
1
ReferenceStationID2
380
12
Intel
Unsigned
1
AgeOfDGNSSCorrections2
392
16
Intel
Unsigned
0.01
The following table provides the offset, minimum and maximum values, unit, and comment for the
GNSSPositionData message.
290
Field Name
Offset
Min
Max
Unit
Comment
SequenceID
0
0
255
PositionDate
0
0
65532
day
Days since January 1, 1970.
Date is relative to UTC time.
PositionTime
0
0
86401
sec
24 hour clock, 0=midnight, time
is in UTC
LatitudeLow
0
0
4.29E07
deg
Latitude referenced to WGS-84
LatitudeHigh
0
-90
90
deg
Latitude referenced to WGS-84
LongitudeLow
0
0
deg
Longitude referenced to WGS84
LongitudeHigh
0
-180
deg
Longitude referenced to WGS84
AltitudeLow
0
0
m
Altitude referenced to WGS-84
AltitudeHigh
0
-9.22
E+12
m
Altitude referenced to WGS-84
TypeOfSystem
0
0
4
0x0 GPS
0x1 GLONASS
0x2 GPS and GLONASS
0x3 GPS and SBAS,
(WAAS/EGNOS)
0x4 GPS and SBAS and
GLONASS
GNSSMethod
0
0
15
0x0 No GPS
0x1 GNSS fix
0x2 DGNSS fix
0x3 Precise GNSS
0x4 RTK fixed integer
0x5 RTK float
0x6 Estimated (DR) mode
0x7 Manual input
0x8 Simulate mode
0xE Error
An upward counting number
used to tie related information
together between different
PGNS
Commands and Messages
GNSSIntegrity
0
0
3
0x0 No integrity checking
0x1 Safe
0x2 Caution
0X3 Unsafe
GNSS_Reserved1
0
0
63
NumberOfSVs
0
0
252
Numeric count, event counter
HDOP
0
327.64
327.64
Dilution of Precision (DOP)
indicates the contribution of
satellite configuration geometry
to positioning error
PDOP
0
327.64
327.64
Dilution of Precision (DOP)
indicates the contribution of
satellite configuration geometry
to positioning error
GeodalSeparation
0
-2.15
E+07
2.15
E+07
NumberOfReferenceStations
0
0
252
Number of reference stations
reported
ReferenceStationType1
0
0
15
0x0 GPS
0x1 GLONASS
0xE Error
ReferenceStationID1
0
0
4095
Reference station ID
AgeOfDGNSSCorrections1
0
0
655.32
ReferenceStationType2
0
0
15
0x0 GPS
0x1 GLONASS
0xE Error
ReferenceStationID2
0
0
4095
Reference station ID
AgeOfDGNSSCorrections2
0
0
655.32
m
sec
sec
The difference between the
earth ellipsoid and mean sealevel (period), defined by the
reference datum used in the
position solution.
'-' indicates mean sea-level
below ellipsoid
Age of differential corrections
Age of differential corrections
Additional
Information
Related
Commands
291
Hemisphere GPS Technical Reference v1.02
GNSSPositionRapidUpdates Message
Message
Type
NMEA 2000 CAN
Description
Abbreviated GPS position information
The GNSSPositionRapidUpdates message (PGN 0x1F801/129025) has an update rate equal to the
subscribed rate (default of 10 Hz) and DLC of 8.
Command
Format to
Request
Message
Message is continuously output on A100 CAN port
Message
Format
The following table provides the start bit, length (bit), value type, factor, and offset for fields of the
GNSSPositionRapidUpdates message.
Additional
Information
Related
Commands
292
Field
Name
Start
bit
Length
(Bit)
Byte
Order
Value
Type
Factor
Offset
Min
Max
Unit
Latitude
0
32
Intel
Signed
0.0000001
0
-90
90
deg
Longitude
32
32
Intel
Signed
0.0000001
0
180
180
deg
Commands and Messages
GPALM Message
Message
Type
Data
Description
Message number (individual and total), week number, satellite health, and the almanac data for each
satellite in the GPS constellation, up to a maximum of 32 messages
Command
Format to
Request
Message
$JASC,GPALM,R[,OTHER]<CR><LF>
Message
Format
where
•
R = message rate (in Hz) of (1 or 0)
•
,OTHER = optional field, enacts a change on the current port when you send the command without
it (and without the brackets) and enacts a change on the other port when you send the command
with it (without the brackets)
$GPALM,A.B,C.D,E,F,hh,hhhh,...*CC<CR><LF>
where:
Response Component
Description
A
Total number of messages
B
Message number
C
Satellite PRN number
D
GPS week number (0-1023)
E
Satellite health (bits 17-24 of message)
F
Eccentricity
hh
t index OA, almanac reference time
hhhh
sigma index 1, inclination angle
Example
$>
$GPALM,31,1,02,1617,00,50F6,0F,FD98,FD39,A10CF3,81389B,423632,BD913C,148,001*3C
$GPALM,31,2,03,1617,00,71B9,0F,F6C2,FD45,A10C96,2B833C,131DB4,BA69EE,2B1,001*3A
$GPALM,31,3,04,1617,00,4F01,0F,FD03,FD39,A10BFC,1C6C35,42EDB1,35B537,112,003*45
$GPALM,31,4,05,1617,00,121B,0F,08C8,FD61,A10C5C,09CA99,6D7257,021B32,79F,7FE*3E
$GPALM,31,5,06,1617,00,337F,0F,FB6B,FD49,A10CC2,DBE103,161127,10CD11,18C,7FE*4A
.
.
.
$GPALM,31,29,30,1617,00,6A85,0F,0ADD,FD5C,A11A83,3F6243,EBCC46,E8548D,145,001*00
$GPALM,31,30,31,1617,00,4037,0F,1778,FD3E,A10C28,D62817,C32ADF,781125,01B,001*7E
$GPALM,31,31,32,1617,00,65B5,0F,0956,FD65,A10DD0,DD74BA,71125D,985AE3,751,7FE*72
Additional
Information
Similar to the GLONASS message GLMLA
Related
Commands
JASC,GP
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Hemisphere GPS Technical Reference v1.02
GPDTM Message
Message
Type
Data
Description
Datum reference
Command
Format to
Request
Message
$JASC,GPDTM,R[,OTHER]<CR><LF>
Message
Format
where
•
R = message rate (in Hz) of (1 or 0)
•
,OTHER = optional field, enacts a change on the current port when you send the command without
it (and without the brackets) and enacts a change on the other port when you send the command
with it (without the brackets)
$GPDTM,ccc,a,x.x,a,x.x,a,x.x,ccc*CC<CR><LF>
where:
Example
Response
Component
Description
ccc
Local datum (normally W84, but could be NAD83 when using beacon in North America)
a
Local datum subdivision code
x.x,a
Lat offset, in minutes, N/S
x.x,a
Lon offset, minutes, E/W
x.x
Altitude offset, in meters
ccc
Reference datum (always W84)
*CC
Checksum
<CR>
Carriage return
<LF>
Line feed
$GPDTM,W84,,0.0,N,0.0,E,0.0,W84*CC<CR><LF>
Additional
Information
Related
Commands
294
JASC,GP
Commands and Messages
GPGGA Message
Note: This topic provides information pertaining to GPS. The format is the same for the messages pertaining to GNSS and
GLONASS (see Additional Information below).
Message
Type
Data
Description
Detailed GPS position information (most frequently used NMEA 0183 data message)
Command
Format to
Request
Message
$JASC,GPGGA,R[,OTHER]<CR><LF>
Message
Format
where
•
R = message rate (in Hz) of 20, 10, 5, 4, 2, 1, 0, or .2 (0 turns off the message)
•
,OTHER = optional field, enacts a change on the current port when you send the command without it
(and without the brackets) and enacts a change on the other port when you send the command with
it (without the brackets)
$GPGGA,HHMMSS.SS,DDMM.MMMMM,S,DDDMM.MMMMM,S,N,QQ,PP.P,AAAA.AA,M,±XX.XX,M,
SSS,AAAA*CC<CR><LF>
where:
Message
Component
Description
HHMMSS.SS
UTC time in hours, minutes, and seconds of the GPS position
DDMM.MMMMM
Latitude in degrees, minutes, and decimal minutes
S
S = N (North latitude ) or S (South latitude)
DDDMM.MMMMM
Longitude in degrees, minutes, and decimal minutes
S
S = E (East longitude) or W (West longitude)
N
Quality indicator
•
•
•
0 = no position
•
4 = RTK fixed integer (Crescent RTK, Eclipse RTK), OmniSTAR XP/HP
converged
•
5 = OmniSTAR XP/HP converging
1 = undifferentially corrected position (autonomous)
2 = differentially corrected position (SBAS, DGPS, OmniSTAR VBS, LDif and e-Dif)
QQ
Number of satellites used in position computation
PP.P
Horizontal dilution of precision (HDOP), ranging from 0.0 to 9.9
AAAA.AA
Antenna altitude
M
Altitude units, in meters
+/-XX.XX
Geoidal separation (needs geoidal height option)
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Hemisphere GPS Technical Reference v1.02
M
Geoidal separation units, in meters
SSS
Age of differential corrections, in seconds
AAAA
Reference station identification
*CC
Checksum
<CR>
Carriage return
<LF>
Line feed
Example
$GPGGA,175250.00,3333.42646711,N,11153.35317335,W,2,07,1.3,406.854,M,
-26.294,M,10.4,0100*4F
Additional
Information
This message provides information specific to the satellite system identified by the first two characters of the
message.
GPGGA - GPS information
GNGGA - GNSS information
GLGGA - GLONASS information
The JNMEA,GGAALLGNSS command significantly affects the output of the GGA message. If you are
tracking more than GPS signals, Hemisphere GPS highly recommends that you review this command.
Related
Commands
296
JASC,GP, JASC,GN, JASC,GL, JNMEA,GGAALLGNSS
Commands and Messages
GPGLL Message
Note: This topic provides information pertaining to GPS. The format is the same for the messages pertaining to GNSS and
GLONASS (see Additional Information below).
Message
Type
Data
Description
Latitude and longitude data
Command
Format to
Request
Message
$JASC,GPGLL,R[,OTHER]<CR><LF>
Message
Format
where
•
'R' = message rate in Hz of 20, 10, 2, 1, 0, or .2 (0 turns off the message)
•
',OTHER' = optional field, enacts a change on the current port when you send the
command without it (and without the brackets) and enacts a change on the other port
when you send the command with it (without the brackets)
$GPGLL,DDMM.MMMMM,S,DDDMM.MMMMM,S,HHMMSS.SS,S*CC<CR><LF>
where:
Additional
Information
Message Component
Description
DDMM.MMMMM
Latitude in degrees, minutes, and decimal minutes
S
S = N (North latitude ) or S (South latitude)
DDDMM.MMMMM
Longitude in degrees, minutes, and decimal minutes
S
S = E (East longitude) or W (West longitude)
HHMMSS.SS
UTC time in hours, minutes, and seconds of GPS position
S
Status, S = A (valid) or V (invalid)
*CC
Checksum
<CR>
Carriage return
<LF>
Line feed
This message provides information specific to the satellite system identified by the first two
characters of the message.
GPGLL - GPS information
GNGLL - GNSS information
GLGLL - GLONASS information
The JNMEA,GGAALLGNSS command significantly affects the output of the GLL message. If you
are tracking more than GPS signals, Hemisphere GPS highly recommends that you review this
command.
Related
Commands
JASC,GP, JASC,GN, JASC,GL, JNMEA,GGAALLGNSS
297
Hemisphere GPS Technical Reference v1.02
GPGNS Message
Note: This topic provides information pertaining to GPS. The format is the same for the messages pertaining to GNSS and
GLONASS (see Additional Information below).
Message
Type
Data
Description
Fixes data for single or combined (GPS, GLONASS, possible future satellite systems, and systems combining
these) satellite navigation systems
Command
Format to
Request
Message
$JASC,GPGNS,R[,OTHER]<CR><LF>
Message
Format
where
•
'R' = message rate (in Hz) of 20, 10, 2, 1, 0, or .2 (0 turns off the message)
•
',OTHER' = optional field, enacts a change on the current port when you send the command without it
(and without the brackets) and enacts a change on the other port when you send the command with it
(without the brackets)
$GPGNS,hhmmss.ss,llll.ll,a,yyyyy.yy,a,mm,ss,h.h,a.a,g.g,d.d,r.r*CC<CR><LF>
where:
Additional
298
Message
Component
Description
hhmmss.ss
UTC of position
llll.ll
Latitude, N/S
a
Latitude, N/S
yyyyy.yy
Longitude, E/W
a
Longitude, E/W
mm
Mode indicator
ss
Total number of satellites in use, 00-99
h.h
HDOP
a.a
Antenna altitude, in meters, re: mean-sea-level (geoid)
g.g
Geoidal separation (in meters)
d.d
Age of differential data
r.r
Differential reference station ID
*CC
Checksum
<CR>
Carriage return
<LF>
Line feed
This message provides information specific to the satellite system identified by the first two characters of the
Commands and Messages
Information
message.
GPGNS - GPS information
GNGNS - GNSS information
GLGNS - GLONASS information
The JNMEA,GGAALLGNSS command significantly affects the output of the GNS message. If you are tracking
more than GPS signals, Hemisphere GPS highly recommends that you review this command.
Related
Commands
JASC,GP, JASC,GN, JASC,GL, JNMEA,GGAALLGNSS
299
Hemisphere GPS Technical Reference v1.02
GPGRS Message
Message
Type
Data
Description
Supports Receiver Autonomous Integrity Monitoring (RAIM)
Command
Format to
Request
Message
$JASC,GPGRS,R[,OTHER]<CR><LF>
Message
Format
where
•
'R' = message rate in Hz of 20, 10, 2, 1, 0, or .2 (0 turns off the message)
•
',OTHER' = optional field, enacts a change on the current port when you send the command without
it (and without the brackets) and enacts a change on the other port when you send the command
with it (without the brackets)
$GPGRS.hhmmss.ss,m,x.x ... x.x*CC<CR><LF>
where:
Message
Component
Description
hhmmss.ss
UTC time
m
Mode:
0 = residuals used to calculate the position given in the GPGGA or GPGNS message
1 = residuals were recomputed after the GPGGA or GPGNS message position was
computed
x.x ... x.x
Range residuals, in meters, for satellites used in the navigation solution. Order must
match order of satellite ID numbers in GPGSA message. When GPGRS message is
used, the GPGSA and GPGSV messages are generally required with this message.
*CC
Checksum
<CR>
Carriage return
<LF>
Line feed
Additional
Information
Related
Commands
300
JASC,GP
Commands and Messages
GPGSA Message
Note: This topic provides information pertaining to GPS. The format is the same for the messages pertaining to GNSS and
GLONASS (see Additional Information below).
Message
Type
Data
Description
GPS DOP and active satellite information
Only satellites used in the position computation are present in this message. Null fields are present when
data is unavailable due to the number of satellites tracked.
Command
Format to
Request
Message
Message
Format
$JASC,GPGSA,R[,OTHER]<CR><LF>
where
•
'R' = message rate in Hz of 1 or 0 (0 turns off the message)
•
',OTHER' = optional field, enacts a change on the current port when you send the command without
it (and without the brackets) and enacts a change on the other port when you send the command
with it (without the brackets)
$GPGSA,A,B,CC ... OO,P.P,Q.Q,R.R*CC<CR><LF>
where:
Additional
Information
Message
Component
Description
A
Satellite acquisition mode (M = manually forced to 2D or 3D, A = automatic swap
between 2D and 3D)
B
Position mode (1 = fix not available, 2 = 2D fix, 3 = 3D fix)
CC to OO
Satellites used in the position solution, a null field occurs if a channel is unused
P.P
Position Dilution of Precision (PDOP) = 1.0 to 9.9
Q.Q
Horizontal Dilution of Precision (HDOP) 1.0 to 9.9
R.R
Vertical Dilution of Precision (VDOP) = 1.0 to 9.9
*CC
Checksum
<CR>
Carriage return
<LF>
Line feed
This message provides information specific to the satellite system identified by the first two characters of the
message.
GPGSA - GPS information
GNGSA - GNSS information
GLGSA - GLONASS information
Related
Commands
JASC,GP, JASC,GN, JASC,GL
301
Hemisphere GPS Technical Reference v1.02
GPGST Message
Message
Type
Data
Description
GNSS pseudorange error statistics and position accuracy
Command
Format to
Request
Message
$JASC,GPGST,R[,OTHER]<CR><LF>
Message
Format
where
•
'R' = message rate in Hz of 1 or 0 (0 turns off the message)
•
',OTHER' = optional field, enacts a change on the current port when you send the command without
it (and without the brackets) and enacts a change on the other port when you send the command
with it (without the brackets)
$GPGST,HHMMSS.SS,A.A,B.B,C.C,D.D,E.E,F.F,G.G*CC<CR><LF>
where:
Message
Component
Description
HHMMSS.SS
UTC time in hours, minutes, and seconds of the GPS position
A.A
Root mean square (rms) value of the standard deviation of the range inputs to the
navigation process. Range inputs include pseudoranges and differential GNSS
(DGNSS) corrections.
B.B
Standard deviation of semi-major axis of error ellipse, in meters
C.C
Standard deviation of semi-minor axis of error ellipse, in meters
D.D
Error in Eclipse’s semi major axis origination, in decimal degrees, true north
E.E
Standard deviation of latitude error, in meters
F.F
Standard deviation of longitude error, in meters
G.G
Standard deviation of altitude error, in meters
*CC
Checksum
<CR>
Carriage return
<LF>
Line feed
Additional
Information
Related
Commands
302
JASC,GP
Commands and Messages
GPGSV Message
Note: This topic provides information pertaining to GPS. The format is the same for the message pertaining to GLONASS (see
Additional Information below).
Message
Type
Data
Description
GNSS satellite in view
Null fields occur where data is unavailable due to the number of satellites tracked.
Command
Format to
Request
Message
Message
Format
Additional
Information
$JASC,GPGSV,R[,OTHER]<CR><LF>
where
•
'R' = message rate in Hz of 1 or 0 (0 turns off the message)
•
',OTHER' = optional field, enacts a change on the current port when you send the command
without it (and without the brackets) and enacts a change on the other port when you send the
command with it (without the brackets)
$GPGSV,T,M,N,II,EE,AAA,SS,…II,EE,AAA,SS*CC<CR><LF>
where:
Message
Component
Description
T
Total number of messages
M
Message number (1 to 3)
N
Total number of satellites in view
II
Satellite number
EE
Elevation, in degrees (0 to 90)
AAA
Azimuth (true), in degrees (0 to 359)
SS
Signal strength, in dB-Hz (0 - 99)
To compare with SNR values found in Bin messages (such as Bin96 )
subtract 30 from this signal strength value for an approximate SNR value
SS - 30 = SNR (from Bin message)
*CC
Checksum
<CR>
Carriage return
<LF>
Line feed
This message provides information specific to the satellite system identified by the first two characters of
the message.
GPGSV - GPS information
GLGSV - GLONASS information
If you request GNGSV the receiver will respond with GPGSV messages only.
Related
Commands
JASC,GP, JASC,GL
303
Hemisphere GPS Technical Reference v1.02
GPHDG/HEHDG Message
Message
Type
Data
Description
Magnetic deviation and variation for calculating magnetic or true heading
The message simulates data from a magnetic sensor although it does not actually contain one. The
purpose of this message is to support older systems that may not be able to accept the HDT message that
is recommended for use.
Command
Format to
Request
Message
Message
Format
$JASC,GPHDG,R[,OTHER]<CR><LF>
where
•
'R' = message rate in Hz of 20, 10, 2, 1, 0 or .2 (0 turns off the message)
•
',OTHER' = optional field, enacts a change on the current port when you send the command
without it (and without the brackets) and enacts a change on the other port when you send the
command with it (without the brackets)
$GPHDG,s.s,d.d,D,v.v,V*CC<CR><LF>
or
$HEHDG,s.s,d.d,D,v.v,V*CC<CR><LF>
where:
Message
Component
Description
s.s
Magnetic sensor reading, in degrees
d.d
Magnetic deviation, in degrees
D
E = Easterly deviation, W = Westerly deviation
v.v
Magnetic variation, in degrees
V
E = Easterly deviation, W = Westerly deviation
*CC
Checksum
<CR>
Carriage return
<LF>
Line feed
Additional
Information
You can change the HDG message header to either GP or HE using the JATT,NMEAHE command.
Related
Commands
JASC,GP
304
Commands and Messages
GPHDM/HEHDM Message
Message
Type
Data
Description
Magnetic heading of the vessel derived from the true heading calculated
Command
Format to
Request
Message
$JASC,GPHDM,R[,OTHER]<CR><LF>
Message
Format
where
•
'R' = message rate in Hz of 20, 10, 2, 1, 0 or .2 (0 turns off the message)
•
',OTHER' = optional field, enacts a change on the current port when you send the command
without it (and without the brackets) and enacts a change on the other port when you send the
command with it (without the brackets)
$GPHDM,x.x,M*CC<CR><LF>
or
$HEHDM,x.x,M*CC<CR><LF>
where:
Message
Component
Description
x.x
Current heading, in degrees
M
Indicates magnetic heading
*CC
Checksum
<CR>
Carriage return
<LF>
Line feed
Additional
Information
You can change the HDM message header to either GP or HE using the JATT,NMEAHE command.
Related
Commands
JASC,GP
305
Hemisphere GPS Technical Reference v1.02
GPHDT/HEHDT Message
Message
Type
Data
Description
True heading of the vessel
This is the direction that the vessel (antennas) is pointing and is not necessarily the direction of vessel
motion (the course over ground).
Command
Format to
Request
Message
Message
Format
$JASC,GPHDT,R[,OTHER]<CR><LF>
where
•
'R' = message rate in Hz of 20, 10, 2, 1, 0 or .2 (0 turns off the message)
•
',OTHER' = optional field, enacts a change on the current port when you send the command
without it (and without the brackets) and enacts a change on the other port when you send the
command with it (without the brackets)
$GPHDT,x.x,T*CC<CR><LF>
or
$HEHDT,x.x,T*CC<CR><LF>
where:
Message
Component
Description
x.x
Current heading, in degrees
T
Indicates true heading
*CC
Checksum
<CR>
Carriage return
<LF>
Line feed
Additional
Information
You can change the HDT message header to either GP or HE using the JATT,NMEAHE command.
Related
Commands
JASC,GP
306
Commands and Messages
GPHEV Message
Message
Type
Data
Description
Heave value in meters
Command
Format to
Request
Message
$JASC,GPHEV,1<CR><LF>
Message
Format
$GPHEV,H,*CC<CR><LF>
where:
Message
Component
Description
H
Heave value, in meters
*CC
Checksum
<CR>
Carriage return
<LF>
Line feed
Additional
Information
Related
Commands
JASC,GP
307
Hemisphere GPS Technical Reference v1.02
GPRMC Message
Message
Type
Data
Description
Contains recommended minimum specific GNSS data
Command
Format to
Request
Message
$JASC,GPRMC,R[,OTHER]<CR><LF>
Message
Format
where
•
'R' = message rate in Hz of 10, 2, 1, 0, or .2 (0 turns off the message)
•
',OTHER' = optional field, enacts a change on the current port when you send the command
without it (and without the brackets) and enacts a change on the other port when you send the
command with it (without the brackets)
$GPRMC,HHMMSS.SS,A,DDMM.MMM,N,DDDMM.MMM,W,Z.Z,Y.Y,DDMMYY,D.D,V
*CC<CR><LF>
where:
Message
Component
Description
HHMMSS.SS
UTC time in hours, minutes, and seconds of the GPS position
A
Status (A = valid, V = invalid)
DDMM.MMM
Latitude in degrees, minutes, and decimal minutes
N
Latitude location (N = North latitude, S = South latitude)
DDDMM.MMM
Longitude in degrees, minutes, and decimal minutes
W
Longitude location (E = East longitude, W = West longitude)
Z.Z
Ground speed, in knots
Y.Y
Track made good, reference to true north
DDMMYY
UTC date of position fix in day, month, and year
D.D
Magnetic Variation, in degrees
V
Variation sense (E = East, W = West)
*CC
Checksum
<CR>
Carriage return
<LF>
Line feed
Additional
Information
Related
Commands
308
JASC,GP
Commands and Messages
GPROT/HEROT Message
Message
Type
Data
Description
Vessel’s rate of turn (ROT) information
Command
Format to
Request
Message
$JASC,GPROT,R[,OTHER]<CR><LF>
Message
Format
where
•
'R' = message rate in Hz of 20, 10, 2, 1, 0 or .2 (0 turns off the message)
•
',OTHER' = optional field, enacts a change on the current port when you send the command
without it (and without the brackets) and enacts a change on the other port when you send the
command with it (without the brackets)
$GPROT,x.x,A*CC<CR><LF>
or
$HEROT,x.x,A*CC<CR><LF>
where:
Message
Component
Description
x.x
Rate of turn in °/min (negative when the vessel bow turns to port)
A
Flag indicating the data is valid
*CC
Checksum
<CR>
Carriage return
<LF>
Line feed
Additional
Information
You can change the ROT message header to either GP or HE using the JATT,NMEAHE command.
Related
Commands
JASC,GP
309
Hemisphere GPS Technical Reference v1.02
GPRRE Message
Message
Type
Data
Description
Satellite range residuals and estimated position error
Command
Format to
Request
Message
$JASC,GPRRE,R[,OTHER]<CR><LF>
Message
Format
where
•
'R' = message rate in Hz of 1 or 0 (0 turns off the message)
•
',OTHER' = optional field, enacts a change on the current port when you send the command
without it (and without the brackets) and enacts a change on the other port when you send the
command with it (without the brackets)
$GPRRE,N,II,RR ... II,RR,HHH.H,VVV.V*CC<CR><LF>
where:
Message
Component
Description
N
Number of satellites used in position computation
II
Satellite number
RR
Range residual, in meters
HHH.H
Horizontal position error estimate, in meters
VVV.V
Vertical position error estimate, in meters
*CC
Checksum
<CR>
Carriage return
<LF>
Line feed
Additional
Information
Related
Commands
310
JASC,GP
Commands and Messages
GPVTG Message
Message
Type
Data
Description
Course over ground and ground speed
Command
Format to
Request
Message
$JASC,GPVTG,R[,OTHER]<CR><LF>
Message
Format
where
•
'R' = message rate in Hz of 20, 10, 2, 1, 0, or .2 (0 turns off the message)
•
',OTHER' = optional field, enacts a change on the current port when you send the command
without it (and without the brackets) and enacts a change on the other port when you send the
command with it (without the brackets)
$GPVTG,TTT,T,MMM,M,NNN.NN,N,KKK.KK,K,X*CC<CR><LF>
where:
Example
Message
Component
Description
TTT
True course over ground (COG) in degrees (000 to 359)
T
True course over ground indicator (always 'T')
MMM
Magnetic course over ground in degrees (000 to 359)
M
Magnetic course over ground indicator (always 'M')
NNN.NN
Speed over ground in knots
N
Speed over ground in knots indicator (always 'N')
KKK.KK
Speed over ground in km/h
K
Speed over ground in km/h indicator (always 'K')
X
Mode
A = Autonomous mode
D = Differential mode
E = Estimated (dead reckoning) mode
M = Manual input mode
S = Simulator mode
N = Data not valid
*CC
Checksum
<CR>
Carriage return
<LF>
Line feed
Sample message output:
311
Hemisphere GPS Technical Reference v1.02
$GPVTG,103.85,T,92.79,M,0.14,N,0.25,K,D*1E
Additional
Information
Related
Commands
312
JASC,GP
Commands and Messages
GPZDA Message
Message
Type
Data
Description
UTC time and date information
Command
Format to
Request
Message
$JASC,GPZDA,R[,OTHER]<CR><LF>
Message
Format
where
•
'R' = message rate in Hz of 20, 10, 2, 1, 0, or .2 (0 turns off the message)
•
',OTHER' = optional field, enacts a change on the current port when you send the command
without it (and without the brackets) and enacts a change on the other port when you send the
command with it (without the brackets)
$GPZDA,HHMMSS.SS,DD,MM,YYYY,XX,YY*CC<CR><LF>
where:
Message
Component
Description
HHMMSS.SS
UTC time in hours, minutes, and seconds of the GPS unit
DD
Day (0 to 31)
MM
Month (1 to 12)
YYYY
Year
XX
Local zone description in hours (-13 to 13)
YY
Local zone description in minutes (0 to 59)
*CC
Checksum
<CR>
Carriage return
<LF>
Line feed
Additional
Information
Related
Commands
JASC,GP
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Hemisphere GPS Technical Reference v1.02
NMEACogSogData Message
Message
Type
NMEA 2000 CAN
Description
GPS speed and direction information
The NMEACogSogData command (PGN 0x1F802/129026) has an update rate equal to the subscribed rate
(default of 10 Hz) and DLC of 8.
Command
Format to
Request
Message
Message is continuously output on A100 CAN port
Message
Format
The following table describes the fields of the NMEACogSogData message:
Additional
Information
Related
Commands
314
Field Name
Start
Bit
Length
(Bit)
Byte
Order
Value
Type
Factor
Min
Max
Comment
NMEA_SequenceID
0
8
Intel
Unsigned
1
0
255
An upward
counting
number
used to tie
related
information
together
between
different
PGNs
NMEA_Direction
Reference
8
2
Intel
Unsigned
1
0
3
0x0 True
north
0x1
Magnetic
north
0x2 Error
0X3 Null
NMEA_Reserved1
10
6
Intel
Unsigned
1
0
63
NMEA_Course
OverGround
16
16
Intel
Unsigned
0.0001
0
6.5535
GPS based
travel
direction, in
rad
NMEA_Speed
OverGround
32
16
Intel
Unsigned
0.01
0
655.35
GPS based
travel
speed, in
m/s
NMEA_Reserved2
48
16
Intel
Unsigned
1
0
65535
Commands and Messages
PASHR Message
Message
Type
Crescent Vector, Data
Description
Time, heading, roll, and pitch data in one message
Command
Format to
Request
Message
$JASC,PASHR,R[,OTHER]<CR><LF>
Message
Format
where
•
'R' = message rate (0 = Off, 1 = On at 1Hz)
•
',OTHER' = optional field, enacts a change on the current port when you send the command without
it (and without the brackets) and enacts a change on the other port when you send the command
with it (without the brackets). See Configuring the Data Message Output for detailed information on
'THIS' and 'OTHER' port terminology.
$PASHR,hhmmss.ss,HHH.HH,T,RRR.RR,PPP.PP,heave,rr.rrr,pp.ppp,hh.hhh,QF*CC
<CR><LF>
where:
Message Component
Description
hhmmss.ss
UTC time
HHH.HH
Heading value in decimal degrees
T
True heading (T displayed if heading is relative to true north)
RRR.RR
Roll in decimal degrees (- sign will be displayed when applicable)
PPP.PP
Pitch in decimal degrees (- sign will be displayed when applicable)
heave
Heave, in meters
rr.rrr
Roll standard deviation in decimal degrees
pp.ppp
Pitch standard deviation in decimal degrees
hh.hhh
Heading standard deviation in decimal degrees
QF
Quality Flag
•
•
•
0 = No position
1 = All non-RTK fixed integer positions
2 = RTK fixed integer position
*CC
Checksum
<CR>
Carriage return
<LF>
Line feed
Additional
Information
Related
Commands
JASC,PASHR
315
Hemisphere GPS Technical Reference v1.02
PSAT,GBS Message
Message
Type
Data
Description
Used to support Receiver Autonomous Integrity Monitoring (RAIM)
Command
Format to
Request
Message
$JASC,GPGBS,R[,OTHER]<CR><LF>
Message
Format
where
•
'R' = message rate in Hz of 1 or 0 (0 turns off the message)
•
',OTHER' = optional field, enacts a change on the current port when you send the command
without it (and without the brackets) and enacts a change on the other port when you send the
command with it (without the brackets)
$PSAT,GBS,hhmmss.ss,ll.l,LL.L,aa.a,ID,p.ppppp,b.b,s.s,flag*CC<CR><LF>
where:
Message
Component
Description
hhmmss.ss
UTC time in hours, minutes, and seconds of the GGA or GNS fix associated with
this sentence
ll.l
Expected error in latitude
LL.L
Expected error in longitude
aa.a
Expected error in altitude
ID
ID number of most likely failed satellite
p.ppppp
Probability of HPR fault
b.b
Estimate of range bias, in meters, on most likely failed satellite
s.s
Standard deviation of range bias estimate
flag
Based on horizontal radius:
0 = Good
1 = Warning
2 = Bad or Fault
*CC
Checksum
<CR>
Carriage return
<LF>
Line feed
Additional
Information
Related
Commands
316
JASC,GP
Commands and Messages
PSAT,HPR Message
Message
Type
Data
Description
Proprietary NMEA message that provides the heading, pitch, roll, and time in a single message
During normal operation heading and pitch are derived from GPS and roll comes from the inertial sensor.
While coasting heading is based on gyro and pitch/roll are from the inertial sensor.
Command
Format to
Request
Message
Message
Format
$JASC,GPHPR,R[,OTHER]<CR><LF>
where
•
'R' = message rate in Hz of 20, 10, 2, 1, 0 or .2 (0 turns off the message)
•
',OTHER' = optional field, enacts a change on the current port when you send the command
without it (and without the brackets) and enacts a change on the other port when you send the
command with it (without the brackets)
$PSAT,HPR,time,heading,pitch,roll,type*CC<CR><LF>
where:
Message
Component
Description
time
UTC time (HHMMSS.SS)
heading
Heading (degrees)
pitch
Pitch (degrees)
roll
Roll (degrees)
type
N for GPS derived heading
G for gyro heading
*CC
Checksum
<CR>
Carriage return
<LF>
Line feed
Additional
Information
Related
Commands
JASC,GP
317
Hemisphere GPS Technical Reference v1.02
PSAT,INTLT Message
Message
Type
Data
Description
Proprietary NMEA message that provides the tilt measurements from the internal inclinometers in degrees.
It delivers an output of crude accelerometer measurements of pitch and roll with no temperature
compensation or calibration for GPS heading/pitch/roll.
Pitch and roll are factory calibrated over temperature to be accurate to ±3°C.
CAUTION: User calibration will clear out precise factory calibration.
Command
Format to
Request
Message
Message
Format
$JASC,INTLT,R[,OTHER]<CR><LF>
where
•
'R' = message rate in Hz of 1 or 0 (0 turns off the message)
•
',OTHER' = optional field, enacts a change on the current port when you send the command
without it (and without the brackets) and enacts a change on the other port when you send the
command with it (without the brackets)
$PSAT,INTLT,pitch,roll*CC<CR><LF>
where:
Message
Component
Description
pitch
Pitch (degrees)
roll
Roll (degrees)
*CC
Checksum
<CR>
Carriage return
<LF>
Line feed
Additional
Information
Related
Commands
318
JASC,GP
Commands and Messages
PSAT,RTKSTAT Message
Message
Type
Data, Local Differential and RTK
Description
Contains the most relevant parameters affecting RTK
Command
Format to
Request
Message
$JASC,PSAT,RTKSTAT,R[,OTHER]<CR><LF>
Message
Format
where
•
'R' = message rate in Hz of 1 or 0 (0 turns off the message)
•
',OTHER' = optional field, enacts a change on the current port when you send the command without
it (and without the brackets) and enacts a change on the other port when you send the command
with it (without the brackets)
$PSAT,RTKSTAT,MODE,TYP,AGE,SUBOPT,DIST,SYS,NUM,SNR,RSF,BSF,HAG*CC<CR><LF>
where:
Message
Component
Description
MODE
FIX,FLT,DIF,AUT,NO
TYP
DFX,ROX,CMR,RTCM3,CMR+,...
AGE
Age of differential corrections
SUBOPT
Subscribed options
DIST
Distance to base in kilometers
SYS
Systems in use:
•
•
•
GPS: L1, L2, L5
GLONASS: G1, G2
Galileo: E5a, E5b, E5a+b, E6
NUM
Number of satellites used by each system
SNR
Quality of each SNR path, where:
•
•
•
•
A is > 20 dB
B is > 18 dB
C is > 15 db
D otherwise
RSF
Rover slip flag (non zero if parity errors in last 5 minutes, good for detecting jamming
and TCXO issues)
BSF
Base slip flag
HAG
Horizontal accuracy guess
*CC
Checksum
<CR>
Carriage return
<LF>
Line feed
319
Hemisphere GPS Technical Reference v1.02
Example
$PSAT,RTKSTAT,FIX,ROX,2,007F,9.5,L1,L2,G1,G2,9,5,0,0,A,A,B,B,0,1,
0.001*CC<CR><LF>
•
L1,L2,G1,G2 are the systems in use
•
9 satellites used by L1, 5 for L2, 0 for G1, 0 for G2
•
A,A,B,B = quality of each SNR path
•
RSF = 0
•
BSF = 1
•
HAG = 0.001
Additional
Information
Related
Commands
320
JASC,PSAT,RTKSTAT
Commands and Messages
RD1 Message
Message
Type
Data
Description
SBAS diagnostic information
Command
Format to
Request
Message
$JASC,D1,R[,OTHER]<CR><LF>
Message
Format
$RD1,SEC,WEEK,FREQ,DSPLOCK,BER2,AGC,DDS,DOPPLER,DSPSTAT,ARMSTAT,
DIFFSTAT,NAVCON*CC<CR><LF>
where:
Message
Component
Description
SEC
Second of GPS week (may be a couple of seconds old)
WEEK
GPS week number
FREQ
L-band frequency in MHz (1575.4200 is used for SBAS)
DSPLOCK
N/A
BER2
BER - given for both SBAS satellites being tracked
AGC
L-band signal strength
DDS
0.0 for SBAS
DOPPLER
0 for SBAS
DSPSTAT
Status bit mask for the DSP tracking of SBAS
•
•
•
•
•
•
ARMSTAT
Bit 0 = Carrier lock
Bit 1 = BER OK (Viterbi lock) (yellow LED 2)
Bit 2 = L-Band: DSP got lock and has stable freq; WAAS: Frame sync2
Bit 3 = Frame sync1
Bit 4 = Track mode (same as carrier lock)
Bits 5 - 15 Unused
Status bit mask for the ARM GPS solution (ARM status values shown below)
•
•
•
•
•
•
•
•
Bit 0 = GPS lock (yellow LED 1)
Bit 1 = DGPS valid data
Bit 2 = ARM has lock
Bit 3 = Diff and GPS (flashing green LED 3)
Bit 4 = GPS solution is good (solid green LED 3)
Bit 5 = ARM controls yellow LED 2
Bit 6 = ARM command for yellow LED 2
Bits 7 - 15 Unused
321
Hemisphere GPS Technical Reference v1.02
DIFFSTAT
SBAS PRN of the satellite in use
NAVCON
Series of hex character fields with each field representing the number of GPS satellites
satisfying a certain condition, all of which conditions are required if the satellite is to be
used in the solution
Example of NAVCON for the value 179889A shown below (read right to left)
322
Description
Value
1 (right
most field)
Hexadecimal count of satellites with valid tracks
A
2
Hexadecimal count of satellites for which an
ephemeris message has been received
9
3
Hexadecimal count of satellites which are healthy
8
4
Hexadecimal count of satellites which passed the
criteria of hex fields 1,2,3 and 5 (satellites that er
tracked, have an ephemeris, are healthy, and are
above the elevation mask)
8
5
Hexadecimal count of satellites above the elevation
mask
9
6
Hexadecimal count of satellites for which a differential
correction is available
7
7
Hexadecimal count of satellites for which a differential
correction is NOT available
1
*CC
Checksum
<CR>
Carriage return
<LF>
Line feed
Additional
Information
Related
Commands
Hex Field
JASC,D1 (RD1)
Commands and Messages
TSS1 Message
Message
Type
Crescent Vector, Data
Description
Heading, pitch, roll, and heave message in the commonly used TSS1 message format
Command
Format to
Request
Message
$JASC,PTSS1,R[,OTHER]<CR><LF>
Message
Format
where
•
'R' = message rate (in Hz) of 0 (off), 0.25, 0.5, 1, 2, 4, 5, 10, or 20 (if subscribed)
•
',OTHER' = optional field, enacts a change on the current port when you send the command without it
(and without the brackets) and enacts a change on the other port when you send the command with it
(without the brackets). See Configuring the Data Message Output for detailed information on 'THIS'
and 'OTHER' port terminology.
:XXAAAASMHHHHQMRRRRSMPPPP*CC<CR><LF>
where:
Message
Component
Description
XX
Horizontal acceleration
AAAA
Vertical acceleration
S
Space character
M
Space if positive; minus if negative
HHHH
Heave
Q
Status flag
Value
Description
h
Heading aided mode (settling) - The System is receiving heading aiding
signals from a gyrocompass but is still awaiting the end of the three
minutes settling period after power-on or a change of mode or heave
bandwidth. The gyrocompass may take several hours to settle after it has
been powered-on. During this time, gyrocompass aiding of the System will
not be perfect. The status flag does NOT indicate this condition.
F
Full aided mode (settled condition) - The System is receiving and using
aiding signals from a gyrocompass and from a GPS receiver or a Doppler
log.
M
Space if positive; minus if negative
RRRR
Roll
S
Space character
M
Space if positive; minus if negative
PPPP
Pitch
323
Hemisphere GPS Technical Reference v1.02
*CC
Checksum
<CR>
Carriage return
<LF>
Line feed
Additional
Information
Related
Commands
324
JASC,PTSS1
Resources
Resources
Reference Documents
National Marine Electronics Association
National Marine Electronics Association (NMEA) Standard for Interfacing Marine Electronic Devices
Version 2.1, October 15, NMEA 1995
7 Riggs Avenue
Severna Park, MD 21146
Tel: +1-410-975-9425
Tel Toll Free: +1-800-808-6632
http://www.nmea.org/
Radio Technical Commission for Maritime Services
RTCM Recommended Standards for Differential NAVSTAR GPS Service Version 2.2
Developed by Special Committee No. 104, RTCM 1998
1800 N Kent St, Suite 1060
Arlington, VA 22209, USA
Tel: +1-703-527-2000
http://www.rtcm.org/
Radio Technical Commission for Aeronautics
Minimum Operational Performance Standards (MOPS) for Global Positioning System/Wide Area Augmentation System
Airborne Equipment
Document RTCA D0-229A, Special Committee No. 159, RTCA 1998
1828 L Street, NW, Suite 805
Washington, D.C. 20036 USA
Tel: +1-202-833-9339
http://www.rtca.org/
ARIC Research Corporation
Interface Control Document, Navstar GPS Space Segment/Navigation User Interfaces
ICD-GPS-200, April 12, 2000
2250 E. Imperial Highway, Suite 450
El Segundo, CA 90245-3509
http://www.navcen.uscg.gov/
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Hemisphere GPS Technical Reference v1.02
Websites
Hemisphere GPS
http://www.hemispheregps.com
FAA WAAS
This site offers general information on the WAAS service provided by the U.S. FAAS.
http://www.faa.gov/about/office_org/headquarters_offices/ato/service_units/techops/navservices/gnss/waas/
ESA EGNOS System Test Bed
This site contains information relating to past performance, real-time performance, and broadcast schedule of EGNOS.
http://www.esa.int/esaNA/egnos.html
Solar and Ionosphereic Activity
The following sites are useful in providing details regarding solar and ionospheric activity.
http://iono.jpl.nasa.gov
http://www.spaceweather.com
326
Troubleshooting
Troubleshooting
Use the following checklist to troubleshoot anomalous receiver system operation.
Receiver fails to power
•
Verify polarity of power leads
•
Check 1.0 A in-line power cable fuse
•
Check integrity of power cable connections
•
Check power input voltage
•
Check current restrictions imposed by power source (minimum available should be > 1.0 A)
No data from receiver
•
Check receiver power status
•
Verify receiver is locked to a valid DGPS signal (this can often be done on the receiving device with the use of the
PocketMAX PC)
•
Verify receiver is locked to GPS satellites (this can often be done on the receiving device with the use of the
PocketMAX PC)
•
Check integrity and connectivity of power and data cable connections
Random data from receiver
•
Verify the RTCM or the Bin95 and Bin96 messages are not being output accidentally (send a JSHOW command)
•
Verify baud rate settings of receiver and remote device match correctly
•
The volume of data requested to be output by the receiver potentially could be higher than the current rate supports.
Try using 19200 or 38400 as the baud rate for all devices.
No GPS lock
•
Check integrity of antenna cable
•
Verify antenna has an unobstructed view of the sky
•
Verify the lock status of the GPS satellites (this can often be done on the receiving device with the use of the
PocketMAX PC)
No SBAS lock
•
Check antenna connections
•
Verify antenna has an unobstructed view of the sky
•
Verify the lock status of SBAS satellites (this can often be done on the receiving device with the use of the
PocketMAX PC - monitor BER value)
No DGPS position in external RTCM mode
•
Verify that the baud rate of the RTCM input port matches the baud rate of the external source
•
Verify the pinout between the RTCM source and the RTCM input port (transmit from the source must go to receiver of
the RTCM input port and grounds must be connected)
327
Hemisphere GPS Technical Reference v1.02
•
Verify the differential mode for the port which RTCM is being imported on is set to JDIFF,THIS
Non-differential GPS output
•
Verify receiver SBAS and lock status, or external source is locked
Multipath signals
•
Operate away from large, reflective structures
•
Use special antennas and GPS equipment to help reduce impact
Intermittent GPS Lock
328
•
Check if receiver is installed in a noisy environment, and if so, shield the PCB
•
Check that the antenna cable is a good quality cable and is not routed around digital or noisy components
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