Survey+ User Manual
Survey+
v2
Inertial
and GNSS
measurement
systems
User Manual
Covers Survey+ and
Survey+ L1 products
Confidently. Accurately.
Legal Notice
Information furnished is believed to be accurate and reliable. However, Oxford
Technical Solutions Limited assumes no responsibility for the consequences of use of
such information nor for any infringement of patents or other rights of third parties
which may result from its use. No license is granted by implication or otherwise under
any patent or patent rights of Oxford Technical Solutions Limited. Specifications
mentioned in this publication are subject to change without notice and do not represent
a commitment on the part of Oxford Technical Solutions Limited. This publication
supersedes and replaces all information previously supplied. Oxford Technical
Solutions Limited products are not authorised for use as critical components in life
support devices or systems without express written approval of Oxford Technical
Solutions Limited.
All brand names are trademarks of their respective holders.
The software is provided by the contributors “as is” and any express or implied
warranties, including, but not limited to, the implied warranties of merchantability and
fitness for a particular purpose are disclaimed. In no event shall the contributors be
liable for any direct, indirect, incidental, special, exemplary, or consequential damages
(including, but not limited to, procurement of substitute goods or services; loss of use,
data, or profits; or business interruption) however caused and on any theory of liability,
whether in contract, strict liability, or tort (including negligence or otherwise) arising in
any way out of the use of this software, even if advised of the possibility of such
damage.
Copyright Notice
© Copyright 2015, Oxford Technical Solutions.
Revision
Document Revision: 150714 (See Revision History for detailed information).
Contact Details
Oxford Technical Solutions Limited
77 Heyford Park
Upper Heyford
Oxfordshire
OX25 5HD
United Kingdom
2
Tel: +44 (0) 1869 238 015
Fax: +44 (0) 1869 238 016
Web: http://www.oxts.com
Email: [email protected]
Oxford Technical Solutions
Survey+ User Manual
Warranty
Oxford Technical Solutions Limited (OxTS) warrants the Survey+ products to be free
of defects in materials and workmanship, subject to the conditions set forth below, for
a period of one year from the Date of Sale.
‘Date of Sale’ shall mean the date of the Oxford Technical Solutions Limited invoice
issued on delivery of the product. The responsibility of Oxford Technical Solutions
Limited in respect of this warranty is limited solely to product replacement or product
repair at an authorised location only. Determination of replacement or repair will be
made by Oxford Technical Solutions Limited personnel or by personnel expressly
authorised by Oxford Technical Solutions Limited for this purpose.
In no event will Oxford Technical Solutions Limited be liable for any indirect,
incidental, special or consequential damages whether through tort, contract or
otherwise. This warranty is expressly in lieu of all other warranties, expressed or
implied, including without limitation the implied warranties of merchantability or
fitness for a particular purpose. The foregoing states the entire liability of Oxford
Technical Solutions Limited with respect to the products herein.
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Table of contents
Scope of delivery
7 Introduction
9 Easy operation
10 Self-correcting
10 Advanced processing
10 Related documents
11 Survey+ family divisions
12 Single antenna
13 Dual antenna
13 GLONASS
13 250 Hz
14 Satellite differential corrections
14 Specification
15 Heading accuracy
17 Environmental protection
17 GNSS antenna operating temperature
17 Export control classification number
17 Conformance notices
Regulator testing standards
18 18 Software installation
19 Hardware installation
21 Survey+ orientation and alignment
21 Antenna placement and orientation
21 Operation
24 Front panel layout
24 LED definitions
25 Co-ordinate frame conventions
Navigation frame
Level frame
27 28 29 4
Oxford Technical Solutions
Survey+ User Manual
Vehicle frame
30 Ethernet configuration
30 Dual antenna systems
Multipath effects on dual antenna systems
32 34 Configuring the Survey+
35 Overview
35 Selecting the operating language
36 Navigating through NAVconfig
36 Product selection
36 Read configuration
38 Orientation
Get improved settings
39 41 Primary antenna position
44 Secondary antenna position
45 Wheel configuration
47 Options
Vehicle starts
Initialisation speed
Camera trigger
GNSS weighting
Heading lock
Displace output
Odometer input
Serial 1 and Serial 2 outputs
Ethernet output
Output smoothing
GNSS control
Coordinate system
Output lock
Differential correction
SBAS
DGNSS service
Advanced
49 50 50 51 51 51 52 52 54 57 58 59 61 63 63 65 65 66 Committing the configuration to the Survey+
66 Saving the configuration and finishing
67 Initialisation process
69 Real-time outputs
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Warm-up period
70 Inputs and outputs
74 Digital inputs and outputs
1PPS output
Event input
Odometer input
Camera trigger
IMU sync output pulse
74 74 75 75 76 76 Reverse polarity protection
76 Laboratory testing
77 Accelerometer test procedure
77 Gyro test procedure
77 Testing the internal GNSS and other circuitry
78 Using the orientation measurements
80 Revision history
81 Drawing list
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Survey+ User Manual
Scope of delivery
Survey+ products are supplied with cables, GNSS antenna, software and manual. In
standard configurations, magnetic mount antennas are provided but other antenna types
are available, please enquire for more details.
Table 1 lists all the items that are delivered with Survey+ systems. Figure 1 shows the
transit box a Survey+ is shipped in along with the included components.
Table 1. Summary of the Survey+ and Survey+2 system components
Qty
Survey+
Qty
Survey+2
Description
1
1
Survey+ system unit
1
1
User cable (14C0121A)
1
2
GNSS antenna G5Ant-2AMNS1
1
2
5 m GNSS antenna cable
1
1
Null modem serial cable
1
1
CD-ROM with manual and software
1
1
User manual
Survey+ products require the correct differential corrections (L1, L2) in order to work
to full specification. Differential corrections can be supplied by an RT-Base, GPSBase, or other suitable differential correction source.
In addition to the components supplied the user will require a laptop to configure the
Survey+.
Revision: 150714
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Figure 1. Typical Survey+ transit box
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Oxford Technical Solutions
Survey+ User Manual
Introduction
The Survey+ series of products from Oxford Technical Solutions are highly accurate
inertial navigation systems (INS) for making precision measurements of position and
motion in real-time.
Designed for use in survey applications, the Survey+ products are one-box solutions for
a complete navigation system. Using complex algorithms to seamlessly blend inertial
and GNSS data, the Survey+ produces smooth position and velocity measurements as
well as other important measurements such as heading, pitch, and roll.
An inertial sensor block with three accelerometers and three angular rate sensors is
used to compute all the outputs. A WGS-84 modelled strapdown navigator algorithm
compensates for earth curvature, rotation and Coriolis accelerations while
measurements from high-grade, high-rate GNSS receivers update the position and
velocity navigated by the inertial sensors.
This innovative approach gives the Survey+ several distinct advantages over systems
that use GNSS alone:

All outputs remain available continuously during GNSS blackouts when, for
example, the vehicle drives under a bridge.

The Survey+ recognises jumps in the GNSS position and ignores them.

The position and velocity measurements that the GNSS makes are smoothed to
reduce the high-frequency noise.

Pseudo-range and carrier phase measurements from satellites can be used or
rejected individually (tight coupling).

The output measurements can be improved when there are fewer than 4 satellites.

The Survey+ makes many measurements that GNSS cannot make, for example
acceleration, angular rate, heading, pitch, roll, etc.

The Survey+ takes inputs from an odometer in order to improve the drift rate when
no GNSS is available.

The Survey+ has a high (100 Hz or 250 Hz) update rate and a wide bandwidth.

The outputs are available with very low, 3.5 ms latency.
The Survey+ system processes the data in real-time. The real-time results are output via
RS232 and over 10/100 Base-T Ethernet using a UDP broadcast. Outputs are timestamped and refer to GPS time; a 1PPS timing sync can be used to give very accurate
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timing synchronisation between systems. The measurements are synchronised to the
GPS clock.
Easy operation
Installation and operation of the Survey+ could not be simpler. A simple configuration
wizard is used to configure the Survey+. The configuration can be saved to the Survey+
so it can operate autonomously without user intervention. A lot of work has been put
into the initialisation of the inertial algorithms so that the Survey+ can reliably start to
navigate in the vast majority of situations. For example, the Survey+ can initialise
during flight without problems.
The Survey+ outputs standard NMEA messages and a 1PPS signal meaning it can
integrate with external sensors and provide corrections in real time. The single unit
contains the inertial sensors, GNSS receiver, data storage and CPU. All components are
ITAR free for maximum flexibility when operating in multiple countries.
Self-correcting
Unlike conventional inertial navigation systems, the Survey+ uses GNSS to correct all
its measurements. GNSS calculates position, velocity, and (for dual antenna systems)
heading. The raw GNSS measurements can also be utilised when using tight coupling.
Using these measurements the Survey+ is able to keep other quantities, such as roll,
pitch and heading, accurate. Tight coupling of the GNSS and inertial measurements
also means the raw GNSS data can be used. There is no drift from the Survey+ in any
of the measurements while GNSS is present.
Advanced processing
A high raw GNSS data rate coupled with processing forwards and backwards in time
means post-processed Survey+ data can achieve highest level accuracy. In poor GNSS
environments drift times can be halved by using the combined results of processing
once forwards and once backwards in time. OxTS’ proprietary gx/ix™ processing
engine can further improve performance with single satellite aiding algorithms and
tight coupling of the inertial and GNSS measurements, meaning position updates even
with fewer than four satellites in view.
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Oxford Technical Solutions
Survey+ User Manual
Related documents
This manual contains sufficient information about the installation and operation of the
Survey+ system. It is beyond the scope of this manual to provide details on service or
repair. Contact OxTS support or your local representative for any customer service
related inquiries.
There are separate manuals available for further information on some of the software
and communication types mentioned in this manual. Table 2 lists related manuals and
where to find them.
Table 2. Supplementary manuals
Manual
NMEA 0183
Description
Description
NMEA description manual for the NMEA outputs.
www.oxts.com/Downloads/Support/NMEA/nmeaman.pdf
NCOM Manual
and Code
Drivers
NCOM description manual.
NCOM C Code
Drivers
A collection of C functions that can be used to decode the binary protocols from the
Survey+.
www.oxts.com/Downloads/Support/NCOM Manual and Code Drivers/ncomman.pdf
www.oxts.com/Downloads/Support/NCOM Manual and Code Drivers/ncomrx.zip
NAVdisplay
Manual
User manual for the real-time display software NAVdisplay.
www.oxts.com/Downloads/Support/Manuals/NAVdisplayman.pdf
RT Postprocess Manual
User manual for the post-processing software RT Post-process.
NAVgraph
Manual
User manual for the graphing and display software NAVgraph.
www.oxts.com/Downloads/Support/Manuals/rtppman.pdf
www.oxts.com/Downloads/Support/Manuals/NAVgraphman.pdf
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Survey+ family divisions
There are two product models in the Survey+ family; the standard Survey+ and the
Survey+ L1. The Survey+ models use high-grade dual frequency GNSS receivers while
the Survey+ L1 models use single frequency receivers. For each of these models there
are a number of different option variations, all based on the same core system but with
minor differences to address different applications.
Table 3 lists the current model line-up for the Survey+ family. Table 4 lists the current
model line-up for the Survey+ L1 family.
Table 3. Survey+ model options
Product name
Description
Survey+
Base model. Single antenna; 100 Hz; L1, L2 GPS.
Survey+2
Dual antenna; 100 Hz; L1, L2 GPS.
Survey+G
Single antenna; 100 Hz; L1, L2 GPS & GLONASS.
Survey+2G
Dual antenna; 100 Hz; L1, L2 GPS & GLONASS.
Survey+ 250
Single antenna; 250 Hz; L1, L2 GPS.
Survey+2 250
Dual antenna; 250 Hz; L1, L2 GPS.
Survey+G 250
Single antenna; 250 Hz; L1, L2 GPS & GLONASS.
Survey+2G 250
Dual antenna; 250 Hz; L1, L2 GPS & GLONASS.
Table 4. Survey+ L1 model options
Product name
12
Description
Survey+ L1
Base model. Single antenna; 100 Hz; L1, GPS.
Survey+2 L1
Dual antenna; 100 Hz; L1, GPS.
Survey+G L1
Single antenna; 100 Hz; L1, GPS & GLONASS.
Survey+2G L1
Dual antenna; 100 Hz; L1, GPS & GLONASS.
Survey+ 250 L1
Single antenna; 250 Hz; L1, GPS.
Survey+2 250 L1
Dual antenna; 250 Hz; L1, GPS.
Survey+G 250 L1
Single antenna; 250 Hz; L1, GPS & GLONASS.
Survey+2G 250 L1
Dual antenna; 250 Hz; L1, GPS & GLONASS.
Oxford Technical Solutions
Survey+ User Manual
Single antenna
The advanced algorithm in the Survey+ software means that most road vehicle
customers are able to use a single antenna system. The Heading lock and Wheel
configuration features mean that the Survey+ can maintain accurate heading while
stationary and while driving with low vehicle dynamics.
Dual antenna
The dual antenna system gives high accuracy heading information and almost constant
heading performance under all conditions. Single antenna systems can have reduced
heading accuracy on aircraft, boats or in low speed land vehicles.
A dual antenna system is recommended to maintain high accuracy heading for
applications on aircraft, marine vehicles, or road vehicle applications on low-friction
surfaces (e.g. ice).
GNSS-only dual antenna systems require open-sky environments to operate because
they can take several minutes to acquire heading lock. Advanced processing in the
Survey+2 allows relock to occur after 5 s of a sky-obstruction; in this time the
Survey+2’s heading will not have significantly degraded. The fast relock time is made
possible because the Survey+2’s own heading is used to resolve the ambiguities in the
GNSS measurements. Resolution of these ambiguities is what normally takes several
minutes. The heading software in the Survey+2 enables significantly better
performance and coverage compared to GNSS-only solutions.
GLONASS
GLONASS capability adds the ability to utilise the Russian satellite constellation
(GLONASS) as well as the American constellation (GPS). This means an extra 24
satellites are available for the Survey+G to lock on to and obtain position and velocity
updates from.
In open sky conditions, the addition of GLONASS capability is of little benefit as the
GPS signals are unlikely to be interrupted and full accuracy can be achieved almost
100% of the time. However, in situations such as road surveying and mobile mapping,
there are likely to be bridges, trees, and tall buildings that can block the view of
satellites or cause multipath effect errors. In these situations, GPS and GLONASS
receivers are able to maintain 2 cm accurate RTK positioning mode at times when
GPS-only receivers are not. They are also able to re-establish RTK lock and resolve its
ambiguities after an obstruction faster.
Note: at this time, gx/ix processing does not support GLONASS. To take full advantage
of GLONASS capability, standard processing must be used.
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250 Hz
All product divisions have the option of coming with a 250 Hz version of the inertial
measurement unit (IMU). The IMUs used in 100 Hz and 250 Hz products are
essentially the same, both with a fundamental sampling frequency of 2500 Hz. The
difference is the 3D filter used to integrate the accelerations and angular rates has a
smaller time step in the 250 Hz version, allowing a higher update rate.
However, because of the smaller time step, measurements that depend on angular
acceleration are typically noisier on the 250 Hz products. The noise can be managed by
filtering the data to limit the bandwidth.
Satellite differential corrections
To improve the positioning accuracy of standard GNSS, two satellite-based differential
correction services are available to all Survey+ models. These are SBAS and
TERRASTAR.
SBAS services, such as WAAS and EGNOS, are wide-area differential corrections
provided for free. They can provide an accuracy of better than 1 m CEP. WAAS is
available in North America; EGNOS is available in Europe; MSAS is available in
Japan. Other parts of the world are not covered and cannot use this service.
TERRASTAR is a subscription service. Survey+ systems (but not Survey+ L1 systems)
include the necessary hardware to receive the TERRASTAR corrections. It is necessary
to pay TERRASTAR a license fee to activate the corrections. The Survey+ is capable
of using the TERAASTAR-D service, providing better than 10 cm position accuracy.
TERRASTAR is available on all continents. Marine versions also exist.
For more information see TERRASTAR’s web site: http://www.terrastar.net/.
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Survey+ User Manual
Specification
Specifications for the Survey+ can be found in Table 5. These specifications are listed
for operation of the system under the following conditions:

After a warm-up period of 15 minutes continuous operation.

Open sky environment, free from cover by trees, bridges, buildings or other
obstructions. The vehicle must have remained in open sky for at least 5 minutes for
full accuracy.

The vehicle must exhibit some motion behaviour. Accelerations of the unit in
different directions are required so that the Kalman filter can estimate the errors in
the sensors. Without this estimation some of the specifications degrade.

The distance from the Survey+ sensor point to the primary GNSS antenna must be
known by the system to a precision of 5 mm or better. The vibration of the system
relative to the vehicle cannot allow this to change by more than 5 mm. The system
can estimate this value itself in dynamic conditions.

For dual antenna systems, the system must know the relative orientation of the two
antennas to 0.05° or better. The system will estimate this value itself under dynamic
conditions.

For single antenna systems, the heading accuracy is only achieved under dynamic
conditions. Under slow and static conditions the performance will degrade.
Optionally, extended measurement ranges covering 30 g acceleration and 300°/s
angular rate may be requested. The specification using the extended measurement
range sensors can be marginally worse than those listed here.
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Table 5. Typical performance specification for Survey+ systems
Product
Positioning
Survey+
Survey+2
Survey+ L1
Survey+2 L1
GPS L1, L2
GPS L1, L2
GPS L1
GPS L1
GLONASS L1,
L2 (on G models)
GLONASS L1,
L2 (on G models)
GLONASS L1
(on G models)
GLONASS L1
(on G models)
Position accuracy
(CEP)1
1.5 m SPS
0.6 m SBAS
0.4 m DGPS
0.1 m PPP
0.01 m RTK
1.5 m SPS
0.6 m SBAS
0.4 m DGPS
0.1 m PPP
0.01 m RTK
1.8 m SPS
0.6 m SBAS
0.4 m DGPS
1.8 m SPS
0.6 m SBAS
0.4 m DGPS
Velocity accuracy
0.05 km/h RMS
0.05 km/h RMS
0.1 km/h RMS
0.1 km/h RMS
Roll/pitch
0.03° 1σ
0.03° 1σ
0.05° 1σ
0.05° 1σ
Heading
0.1° 1σ
0.05° 1σ
0.1° 1σ
0.05° 1σ
Acceleration
– Bias stability
– Linearity
– Scale factor
– Noise
– Range
5 μg 1σ
0.01 % 1σ
0.1 % 1σ
0.005 m/s/√hr 1σ
10 g
5 μg 1σ
0.01 % 1σ
0.1 % 1σ
0.005 m/s/√hr 1σ
10 g
5 μg 1σ
0.01 % 1σ
0.1 % 1σ
0.005 m/s/√hr 1σ
10 g
5 μg 1σ
0.01 % 1σ
0.1 % 1σ
0.005 m/s/√hr 1σ
10 g
Angular rate
– Bias stability
– Linearity2
– Scale factor
– Noise
– Range
2 °/hr 1σ
0.05 % 1σ
0.1 % 1σ
0.2 °/√hr 1σ
100 °/s
2 °/hr 1σ
0.05 % 1σ
0.1 % 1σ
0.2 °/√hr 1σ
100 °/s
2 °/hr 1σ
0.05 % 1σ
0.1 % 1σ
0.2 °/√hr 1σ
100 °/s
2 °/hr 1σ
0.05 % 1σ
0.1 % 1σ
0.2 °/√hr 1σ
100 °/s
Heave3
10 cm or 10%
10 cm or 10%
10 cm or 10%
10 cm or 10%
Dual antenna
x

x

Update rate
100 Hz / 250 Hz
100 Hz / 250 Hz
100 Hz / 250 Hz
100 Hz / 250 Hz
Input voltage
10–25 V dc
10–25 V dc
10–25 V dc
10–25 V dc
Power consumption
15 W
20 W
15 W
20 W
Dimensions
234 × 120 ×
80 mm
234 × 120 ×
80 mm
234 × 120 ×
80 mm
234 × 120 ×
80 mm
Mass
2.2 kg
2.4 kg
2.2 kg
2.4 kg
Calculation latency
3.5 ms
3.5 ms
3.5 ms
3.5 ms
Operating
temperature4
-10–50°C
-10–50°C
-10–50°C
-10–50°C
Vibration
0.1 g2/Hz, 5–
500 Hz
0.1 g2/Hz, 5–
500 Hz
0.1 g2/Hz, 5–
500 Hz
0.1 g2/Hz, 5–
500 Hz
Shock survival
100 g, 11 ms
100 g, 11 ms
100 g, 11 ms
100 g, 11 ms
Internal storage
2 GB
2 GB
2 GB
2 GB
1
Valid for open sky conditions.
With SuperCAL adjustment.
3
Heave output is not available on 250 Hz systems.
2
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Survey+ User Manual
4
Operating temperature range for the antenna is much wider. See specification below.
Heading accuracy
The heading accuracy that can be achieved by the dual antenna system in the Survey+2
models is 0.2° 1σ per metre of separation in ideal, open sky conditions. The maximum
recommended separation is 5 m, giving an accuracy of 0.05° 1σ. The dual antenna
system can provide these accuracies in static and dynamic conditions.
For single antenna systems, the heading is calculated from the inertial measurements.
The accuracy listed in Table 5 is achievable under dynamic conditions. Under static
conditions the heading accuracy of single antenna systems will degrade.
Non-ideal mounting of the GNSS antennas will reduce the heading accuracy,
particularly for dual antenna systems.
Environmental protection
The Survey+ products are rated to IP65. To achieve IP65 it is necessary to have
connectors fitted to both TNC antenna connectors and to use self-amalgamating tape
over the TNC connectors.
GNSS antenna operating temperature
The GNSS antennas have a much wider operating temperature range, from -55 to
85 °C, allowing them to be used on the outside of vehicles.
Export control classification number
Export control regulations change and so the classification number of the Survey+ may
also change. The information here relates to the time when the manual was published.
The Survey+ products can fall under two different export control categories, depending
on the type of accelerometer fitted internally. The type of accelerometer does not affect
the specification of the product, only the export control classification number (ECCN).
The current ECCN for the Survey+ products is either 7A103a1 or 7A003d. Please see
the invoice or delivery note, or contact OxTS Support to view the ECCN of your
Survey+ system.
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Conformance notices
The Survey+ complies with the radiated emission limits for 47CFR15.109:2010 class A
of Part 15 subpart B of the FCC rules, and with the emission and immunity limits for
class A of EN 55022. These limits are designed to provide reasonable protection
against harmful interference in business, commercial and industrial uses. This
equipment generates, uses and can radiate radio frequency energy and, if not installed
and used in accordance with the instructions, may cause harmful interference to radio
communications. However, there is no guarantee that interference will not occur in a
particular installation. If this equipment does cause harmful interference to radio or
television reception, which can be determined by turning the equipment off and on, the
user is encouraged to try to correct the interference by one or more of the following
measures:

Re-orient or relocate the receiving antenna

Increase the separation between the equipment and the receiver
The Survey+ incorporates a GNSS receiver. Any GNSS receiver will not be able to
track satellites in the presence of strong RF radiations within 70 MHz of GNSS
frequencies.
The Survey+ conforms to the requirements for CE.
Any use or misuse of the Survey+ in a manner not intended may impair the protection
provided. OxTS is not liable for any damages caused by the misuse of the equipment.
Regulator testing standards

47CFR15.109:2010 class A (radiated emissions)

EN 300 440-1:2008, test methods 8.3.2 (conducted emissions) and 8.3.3 (radiated
emissions)

EN 55022 class A according to standard EN 301 489-1:2008 (conducted
emissions)

EN 6100-4-3 criterion A according to standard EN 301 489-1:2008 (radiated
immunity)

ISO7637-2 criterion B, 12V according to standard EN 301 489-1:2008 (vehicular
transients and surges immunity).
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Survey+ User Manual
Software installation
Included with every Survey+ is a CD containing the software package NAVsuite. This
package contains a number of programs required to take full advantage of the
Survey+’s capabilities. Table 6 lists the contents of NAVsuite.
Table 6. NAVsuite components
Icon
Software
NAVdisplay
Enginuity
Description
Used to view real-time data from OxTS products via
Ethernet or a serial port. It can also be used to transmit
special commands and replay logged data.
Predecessor to NAVdisplay. Enginuity is included in the
NAVsuite installation for legacy customers.
NAVconfig
Used to create, send, and receive configurations from OxTS
products. As configurations vary between products there is
no manual for NAVconfig. The options relevant to the
Survey+ products are covered in this manual on page 35.
RT Post-Process
Used to download raw data files from the Survey+ and postprocess the data. The configuration can be changed and
differential corrections can be applied before the data is
reprocessed. It can export NCOM, XCOM and CSV file
formats.
NAVgraph
Used to graph NCOM, XCOM and RCOM files created in
post-process. It can display graphs, cursor tables and map
plots and data can be exported in CSV or KML (Google
Earth) format.
Manuals
This folder contains PDF versions of relevant OxTS
manuals. Other manuals can be downloaded from the OxTS
website, http://www.oxts.com/support/manuals/.
To install NAVsuite, insert the CD and run NAVsetup.exe. Follow the onscreen
instructions to install the software. By default the installer creates the program files in
C:\Program Files (x86)\OxTS on 64-bit operating systems or C:\Program Files\OxTS
on 32-bit operating systems.
The first time some OxTS applications are run a firewall warning message similar to
that shown in Figure 2 may be triggered. This is because the program is attempting to
Revision: 150714
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listen for, and communicate with, OxTS devices on the network. The firewall must be
configured to allow each program to talk on the network, or programs will not work as
intended.
Figure 2. Windows Firewall warning message
Ensure both Private and Public networks are selected to ensure the software can continue functioning
when moving from one type to another.
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Survey+ User Manual
Hardware installation
It is essential to install the Survey+ rigidly in the vehicle. The Survey+ should not be
able to move or rotate compared to either GNSS antenna, otherwise the performance
will be reduced. In most circumstances the Survey+ should be mounted directly to the
chassis of the vehicle. If the vehicle experiences high shocks then vibration mounts
may be required.
The Survey+ is compatible with the RT-Strut product from OxTS to provide a quick
and secure vehicle mounting solution.
Do not install the Survey+ where it is in direct sunlight as, in hot countries, this may
cause the case to exceed the maximum temperature specification.
Survey+ orientation and alignment
The orientation of the Survey+ in the vehicle is normally specified using three
consecutive rotations that rotate the Survey+ to the vehicle’s co-ordinate frame. The
order of the rotations is heading (z-axis rotation), then pitch (y-axis rotation), then roll
(x-axis rotation). The Survey+ co-ordinate conventions are detailed on page 27. It is
important to get the order of the rotations correct.
In the default configuration the Survey+ expects its y-axis to be pointing right and its zaxis pointing down relative to the host vehicle. There are times however when
installing a Survey+ in the default configuration is not possible, for example when
using the RT-Strut. The Survey+ can be mounted at any angle in the vehicle as long as
the configuration is described to the Survey+ using NAVconfig. This allows the outputs
to be rotated based on the settings entered to transform the measurements to the vehicle
frame.
For ease of use it is best to try and mount the Survey+ so its axes are aligned with the
vehicle axes. This saves the offsets having to be measured by the user. If the system
must be mounted misaligned with the vehicle and the user cannot accurately measure
the angle offsets, the Survey+ has some functions to measure these offsets itself. The
heading offset can be measured if the vehicle has a non-steered axle. The Wheel
configuration and Improve configuration utilities should be used for this (see pages 47
and 41).
Antenna placement and orientation
For optimal performance it is essential for the GNSS antenna(s) to be mounted where
they have a clear, uninterrupted view of the sky and on a suitable ground plane, such as
the roof of a vehicle. For good multipath rejection the antennas must be mounted on a
metal surface using the magnetic mounts provided; no additional gap may be used.
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The antennas cannot be mounted on non-conducting materials or near the edges of
conducting materials. If the antennas are to be mounted with no conductor below them
then different antennas must be used. It is recommended to mount the antennas at least
30 cm from any edge where possible.
For dual antenna systems, the secondary antenna should be mounted in the same
orientation as the primary antenna, as shown in Figure 3. The antenna baseline should
also be aligned with one of the vehicle axes where possible, either inline or
perpendicular to the vehicle’s forward axis. In the default configuration the primary
antenna should be at the front of the vehicle and the secondary antenna should be at the
rear.
Figure 3. Dual antenna orientations
A) The bases of the antennas are parallel, but the cables exit in different directions. B) The cables exit in
the same direction but the bases of the antennas are not parallel. C) The bases of the antennas are parallel
and the cables exit in the same direction. This configuration will achieve the best results.
It is best to mount the two antennas on the top of the vehicle. Although it is possible to
mount one on the roof and one on the bonnet (hood), in reality the multipath reflections
from the windscreen will degrade the performance of the system. On aircraft it is best
to mount the antennas on the main aircraft fuselage if the Survey+ is mounted in the
aircraft fuselage itself. If the Survey+ is mounted on a pod under the wings then
mounting the antennas on the pod may give the best results.
Multipath affects dual antenna systems on stationary vehicles more than moving
vehicles and it can lead to heading errors of more than 0.5° RMS if the antennas are
mounted poorly.
It is critical to have the Survey+2 mounted securely in the vehicle. If the angle of the
Survey+2 can change relative to the vehicle then the dual antenna system will not work
correctly. This is far more critical for dual antenna systems than for single antenna
systems. The user should aim to have no more than 0.05° of mounting angle change
throughout the testing. (If the Survey+2 is shock mounted then the Survey+2 mounting
will change by more than 0.05°; this is acceptable, but the hysteresis of the mounting
may not exceed 0.05°).
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For both single and dual antenna systems it is essential that the supplied GNSS antenna
cables are used and not extended, shortened or replaced. This is even more critical for
dual antenna systems and the two antenna cables must be of the same specification. Do
not, for example, use a 5 m antenna cable for one antenna and a 15 m antenna cable for
the other. Do not extend the cable, even using special GNSS signal repeaters that are
designed to accurately repeat the GNSS signal. Cable length options are available in
5 m and 15 m lengths.
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Operation
The Survey+ has been designed to be simple and easy to operate. The front panel label
and LEDs convey some basic information that aid in configuration and troubleshooting.
Once powered, the Survey+ requires no further input from the user to start logging and
outputting data.
This section covers some basic information required for operation of the Survey+.
Front panel layout
Figure 4 shows the layout of the Survey+ front panel. Table 7 lists the parts of the front
panel labelled in Figure 4. The layout is the same for all model divisions in the Survey+
family. For single antenna models, the secondary antenna connector is not connected
internally.
Figure 4. Survey+ front panel layout
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Table 7. Front panel descriptions
Label no.
Description
1
SDNav LED
2
Pos/Head LED
3
GNSS LED
4
Power LED
5
Primary antenna connector
6
User cable main connector
7
Secondary antenna connector
LED definitions
The front panel of the Survey+ has four LEDs. These give an indication of the internal
state of the system and are designed to provide enough feedback so that a laptop does
not need to be connected. They can be used for some simple operational checks on the
system. Table 8 gives a description of each LED and Table 9, Table 10, Table 11,
Table 12, and Table 13 list the precise meanings of the states of each LED.
Table 8. LED descriptions
Name
SDNav
Pos/Head
Description
Strapdown navigator state
Position solution (single antenna) or heading solution (dual antenna) from GNSS
GNSS
Self-test
Power
Power/comms
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Table 9. SDNav LED states
Colour
Description
Off
The operating system has not yet booted and the program is not yet running. This occurs at
start-up.
Red-green
flash
The Survey+ is asleep. Contact OxTS support for further information.
Red flash
The operating system has booted and the program is running. The GNSS receiver has not
yet output a valid time, position, or velocity.
Red
The GNSS receiver has locked-on to satellites and has adjusted its clock to valid time (the
1PPS output will now be valid). The strapdown navigator is ready to initialise. If the
vehicle is travelling faster than the value set for “Initialisation speed” during configuration
then the strapdown navigator will initialise and the system will become active. On dual
antenna systems the system will initialise once the GNSS receiver has determined heading,
even if the vehicle is stationary or moving slowly.
Orange
The strapdown navigator has initialised and data is being output, but the system is not realtime yet. It takes 10 s for the system to become real-time after start up.
Green
The strapdown navigator is running and the system is real-time.
In current versions of the software the strapdown navigator will not leave green and return to any other
state. This may change in future releases.
Table 10. Pos/Head LED states (single antenna systems)
Colour
Off
Red flash
Red
Description
The GNSS receiver is not sending data.
(Start-up only). The GNSS receiver is sending data to the Survey+. This is an operational
check for the GNSS receiver.
The GNSS receiver has a standard position solution (SPS).
Orange
The GNSS receiver has a differential solution (DGPS) or a kinematic floating position
solution (20 cm accuracy).
Green
The GNSS receiver has a kinematic integer position solution (2 cm accuracy).
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Table 11. Pos/Head LED states (dual antenna systems)
Colour
Description
Off
GNSS receiver fault (valid only after start-up).
Red flash
GNSS receiver is active, but has been unable to determine heading.
Red
The GNSS has a differential heading lock.
Orange
The GNSS receiver has a floating (poor) calibrated heading lock.
Green
The GNSS receiver has an integer (good) calibrated heading lock.
Table 12. GNSS LED states
Colour
Description
Green flash
Other
The GNSS receiver is functioning normally.
The GNSS receiver has failed. Contact OxTS for further information.
Table 13. Power LED states
Colour
Off
Description
There is no power to the system or the system power supply has failed.
Green
The 5 V power supply for the system is active.
Orange
The system is outputting data on connector J2.
Co-ordinate frame conventions
The Survey+ uses a co-ordinate frame that is popular with most navigation systems.
Figure 5 shows how the axes relate to the Survey+ box. All measurements to and from
the Survey+ should be made from the measurement origin point shown in Figure 5.
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Figure 5. Survey+ co-ordinate frame and measurement origin
Table 14 lists the directions that the axes should point for zero heading, pitch and roll
outputs when the default mounting orientation is used.
Table 14. Direction of axes for zero heading, pitch and roll outputs
Axis
Direction
Vehicle axis
x
North
Forward
y
East
Right
z
Down
Down
If the axes of the Survey+ and the vehicle axes are not the same as those listed in Table
14, then they can be aligned by reconfiguring the Survey+ for a different mounting
orientation using the NAVconfig software.
If the RT-Strut is being used to mount the Survey+ in the vehicle then NAVconfig will
have to be used to configure the orientation or the Survey+ will not work correctly.
Page 39 gives more information on configuring the orientation of the Survey+ in a
vehicle.
Navigation frame
The navigation frame is used by the Survey+ to integrate the acceleration to velocity
and to integrate the velocity to position. The definition of the navigation frame is listed
in Table 15.
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Table 15. Navigation frame definition
Axis
North
East
Down
Description
Diagram
The north axis (n) is perpendicular to the gravity vector
and in the direction of the north pole along the earth’s
surface.
The east axis (e) is perpendicular to gravity, perpendicular
to the north axis and is in the east direction.
The down axis (d) is along the gravity vector.
Level frame
The level frame is attached to the vehicle but does not rotate with the roll and pitch of
the vehicle. It rotates by the heading of the vehicle. The definition of the level frame is
listed in Table 16 and shown in Figure 6.
Table 16. Level frame definition
Axis
Description
Forward
This is the forward (f) direction of the car, projected in to the horizontal plane.
Lateral
This is the lateral (l) direction of the car, pointing to the right, projected in to the
horizontal plane.
Down
This is the down (d) direction of the car, along the gravity vector.
Figure 6. Level frame definition
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Vehicle frame
The vehicle frame is attached to the body of the vehicle. It is related to the Survey+
through the rotations in the Orientation page of NAVconfig. It can be changed while
the Survey+ is running using the Quick Config tool of NAVdisplay. The definitions of
the vehicle frame are listed in Table 17 and shown in Figure 7.
Table 17. Vehicle frame definition
Axis
Description
x
This is the forward direction of the car.
y
This is the right direction of the car.
z
This is the down direction of the car.
Figure 7. Vehicle frame definition
Ethernet configuration
To configure the Survey+ for unrestricted data transmission it is necessary to use the
Ethernet connection. The operating system at the heart of the Survey+ products allows
connection to the unit via FTP. The use of FTP allows the user to manage the data
logged to the unit; files can be downloaded for reprocessing and deleted to make space
for future files. Configuration files for alternative configurations require FTP to put the
configuration files on to the Survey+. The default username and password are both
‘user’.
The Survey+ outputs its data over Ethernet using a UDP broadcast. The use of a UDP
broadcast allows everyone on the network to receive the data sent by the Survey+. The
data rate of the UDP broadcast is 100 Hz or 250 Hz.
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In order to communicate via Ethernet, each Survey+ is configured with a static IP
address that is shown on the delivery note. If the delivery note is unavailable, the
default IP address normally takes the form 195.0.0.sn, where sn is the last two digits of
the Survey+’s serial number. The serial number can be found on the front panel of the
Survey+ or on the delivery note.
The IP address of the computer being used to communicate with the Survey+ may need
to be changed so it matches the subnet. For example, 195.0.0.200 should be available
since this IP address is never used by the Survey+ by default.
To change the IP address of the computer, follow these steps (applies to Windows
Vista/7/8):
1. Open the Control Panel from the Start menu.
2. In category view, select Network and Internet and then Network and
Sharing Center.
3. Select Change adapter settings in the side panel.
4. Right-click the Ethernet option and select Properties.
5. In the window that opens, navigate the list to find Internet Protocol Version 4
(TCP/IPv4). Select it and click Properties.
6. In the TCP/IPv4 Properties window (Figure 8), select Use the following IP
address and enter the IP address and subnet mask to use.
7. Click OK when finished.
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Figure 8. Configuring the computer's IP address
Once the computer is configured the IP address of a Survey+ can be found by running
NAVdisplay software; this will display the IP address of any Survey+ connected.
Note that it is possible to change the IP address of Survey+ systems. If the IP address
has been changed then NAVdisplay should still be able to identify the address that the
Survey+ is using as long as the PC has a valid IP address and this is not the same as the
Survey+’s.
Dual antenna systems
It is often useful to have an understanding of how the Survey+2 uses the measurements
from the dual antenna system. This can lead to improvements in the results obtained.
1.
To use the measurements properly the Survey+2 needs to know the angle of the
GNSS antennas compared to the angle of the Survey+2. This is very difficult to
measure accurately without specialised equipment, therefore the Survey+2 needs
to measure this itself as part of the warm-up process.
2.
The Survey+2 will lock on to satellites, but it cannot estimate heading so it
cannot start. Either motion or static initialisation can be used to initialise the
Survey+2
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3.
When the vehicle drives forward and reaches the initialisation speed, the
Survey+2 assumes that the heading and track are similar and initialises heading to
track angle.
If the Survey+2 is mounted in the vehicle with a large heading offset then the
initial value of heading will be incorrect. This can also happen if the Survey+2 is
initialised in a turn. This can lead to problems later.
4.
When the combined accuracy of heading plus the orientation accuracy figure for
the secondary antenna is sufficiently accurate then the Survey+2 will solve the
RTK Integer problem using the inertial heading. There is no need for the
Survey+2 to solve the RTK Integer problem by searching.
If the antenna angle is offset from the Survey+2 by a lot then the RTK Integer
solution that is solved will be incorrect. For a 2 m antenna separation the
Survey+2 orientation and the secondary antenna orientation should be known to
within 5°. For wider separations the secondary antenna orientation angle needs to
be more accurate.
5.
Once the RTK Integer solution is available, the Survey+2 can start to use the dual
antenna solution to improve heading. The level of correction that can be applied
depends on how accurately the angle of the secondary antenna is known
compared to the inertial sensors.
6.
The Kalman filter tries to estimate the angle between the inertial sensors and the
secondary antenna. The default value used in the configuration software (5°) is
not accurate enough so that the Survey+2 can improve the heading using this
value. If you want the vehicle heading to 0.1°, but the angle of the two GNSS
antennas is only known to 5°, then the measurements from the antenna are not
going to be able to improve the heading of the vehicle.
Driving a normal warm-up, with stops, starts and turns, helps the Kalman filter
improve the accuracy of the secondary antenna angle. The accuracy of this angle
can be verified in NAVdisplay. On aircraft or marine vehicles some turns are
needed to help the Kalman filter estimate the relative angle of the antennas
compared to the Survey+2.
7.
In the unlikely event that the RTK Integer solution is incorrect at the start then
the Kalman filter can update the secondary antenna orientation incorrectly. If this
happens then things start to go wrong. The Kalman filter becomes more
convinced that it is correct, so it resolves faster, but it always solves incorrectly.
Solving incorrectly makes the situation worse.
To avoid the Kalman filter from getting things wrong it is possible to drive a
calibration run, then use the Improve configuration utility within NAVconfig
(see page 41 for more information). This tells the Kalman filter it has already
estimated the angle of the secondary antenna in the past and it will be much less
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likely to get it wrong or change it. This step should only be done if the Survey+2
is permanently mounted in a vehicle and the antennas are bolted on. Any
movement of either the Survey+2 or the antennas will upset the algorithms.
Multipath effects on dual antenna systems
Dual antenna systems are very susceptible to the errors caused by multipath. This can
be from buildings, trees, roof-bars, etc. Multipath is where the signal from the satellite
has a direct path and one or more reflected paths. Because the reflected paths are not
the same length as the direct path, the GNSS receiver cannot track the satellite signal as
accurately.
The dual antenna system in the Survey+2 works by comparing the carrier-phase
measurements at the two antennas. This tells the system the relative distance between
the two antennas and which way they are pointing (the heading). For the heading to be
accurate the GNSS receivers must measure the relative position to about 3 mm. The
level of accuracy can only be achieved if there is little or no multipath.
In an ideal environment, with no surrounding building, trees, road signs or other
reflective surfaces, the only multipath received is from the vehicle’s roof. The antennas
supplied with the Survey+2 are designed to minimise multipath from the vehicle’s roof
when the roof is made of metal. For use on non-metallic roofs a different type of
antenna is required.
When stationary the heading from the Survey+2 will show some error, the size of the
error depends on the multipath in the environment. Table 18 lists the errors to be
expected when stationary with a 1 m base-line.
Table 18. Typical heading error for when stationary in different environments
Environment
Typical error (3σ
Complete open-sky
0.6°
(0.2° 1σ
Near trees, buildings
1°
Next to trees, buildings
2°
Typical figures using a 1 m base-line. For accuracy specification of 0.1° RMS a 2 m separation is
required. Using a 2 m base-line can halve the figures shown here.
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Configuring the Survey+
To obtain the best results from your Survey+ it will be necessary to configure the
Survey+ to suit the installation and application before using it for the first time.
The program NAVconfig can be used to do this. This section describes how to use
NAVconfig and gives additional explanations on the meanings of some of the terms
used.
It is only possible to change the Survey+ configuration using Ethernet. It is necessary to
have the Ethernet on your computer configured correctly in order to communicate with
the Survey+ and change the settings. See the section “Ethernet configuration” on page
30 for more information.
Overview
In order to give the best possible performance, the Survey+ needs to know the
following things:

The orientation of the Survey+ as it is mounted at in the vehicle.

The position of the primary GNSS antenna compared to the Survey+.

The orientation of the dual antennas compared to the Survey+.

The position of the rear wheels (or non-steering wheels) compared to the Survey+.

The position of the odometer compared to the Survey+.
The Survey+ can work out many of these parameters by itself, but this takes time.
Measuring the parameters yourself and configuring the Survey+ reduces the time taken
to achieve full specification.
In particular, Survey+ products can calculate the position of the GNSS antenna. This
works well when using a base station to achieve 2 cm accuracy, but can take hours with
less accurate positioning modes. It is best to measure the position of the GNSS antenna
to an accuracy of 10 cm or better.
If the Survey+ has been running for some time, it will have improved the
measurements. It is possible to read these improved measurements into NAVconfig,
commit them to the Survey+, then use them next time the system is started. If the
Survey+ is moved from one vehicle to another it is essential to return to the default
configuration rather than using parameters that have been tuned for a different vehicle.
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Selecting the operating language
The NAVconfig software can operate in several languages. To change language, select
the language from the drop-down menu at the bottom of the page. The language is
“hot-swappable” making it easy and fast to switch between languages.
The software will use the regional settings of the computer to choose whether numbers
are represented in the English or European format (dot or comma for the decimal
separator). The selected language does not change the format used for numbers.
Navigating through NAVconfig
NAVconfig provides a ten-step process to make configuring your product as easy as
possible. After completing each step, click the Next button at the bottom of the window
to proceed to the next step. The Back button can be used to return to the previous step
at any time. Clicking Cancel will bring up a warning asking to confirm you want to
close the wizard and lose any changes you have not saved.
To quickly move between any of the steps, click on the step name in the sidebar to
instantly jump to that page.
Measurements are always displayed in metric units in NAVconfig. However, when
entering measurements alternate units can be used as long as they are specified, e.g. 10″
or 10 in. NAVconfig will then convert and display these in metric units.
Product selection
The first page of the NAVconfig configuration wizard lets you select the type of
product for configuration, see Figure 9.
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Figure 9. NAVconfig Product Selection page
The configuration wizard can be run without a system connected so it is necessary to
select the correct product for configuration. Some configuration pages are not available
with some of the products. These will be displayed as grey in the sidebar.
Select “Survey+” from the Product family list, then select the correct model for your
system from the Product model list. There are no “G” models listed as GLONASS
capability does not affect anything in the configuration. Just select the closest model
type instead. For Survey+ models, the Product generation option needs selecting. All
systems built after June 2014 are v2 models. These can also be identified by looking on
the top of the Survey+ system, if there are axes engraved into the lid above the
shockwatch then it is a v2 model. All Survey+ L1 models are v2.
In instances where the same product type will be used each time, the Product Selection
page can be skipped in the future by clicking the Always use this product checkbox. If
a different product needs configuring, the selection page can be returned to by clicking
Product Selection in the sidebar.
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Read configuration
The Read Configuration page gives several options for reading the configuration from
different places as shown in Figure 10.
Figure 10. NAVconfig Read Configuration page
Use default settings: This option tells the configuration wizard to use the default
settings the Survey+ was delivered with.
Note: choosing Use default settings will overwrite any advanced settings you may have
set. To maintain advanced settings the Read initial settings from device option must
be used.
Read settings from a folder: It is possible to store a configuration in a folder. The
configuration requires several files so it is tidier to keep it in a folder by itself. To read
the configuration from a folder select this option and specify a folder by clicking the
Browse… button.
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Read settings from an RD file: The Survey+ writes the configuration it is using to the
internally stored RD file. This option extracts the configuration used and loads it in the
configuration wizard. Specify an RD file by selecting this option and clicking the
Browse… button.
Read initial settings from device: If the Survey+ is connected to the computer via
Ethernet then it is possible to read the initial settings directly from the Survey+. The
settings loaded are the settings that were last committed to the Survey+, before it makes
any improvements. Select this option and enter the correct IP address of your Survey+
or select it from the drop-down list. The list will show all systems that are connected to
the network, so if more than one system is connected ensure you select the correct
system. Note: the list will not function correctly if NAVdisplay or other software is
using the Survey+ UDP port unless the OxTS UDP Server is running.
Orientation
The Orientation page is used to define the vehicle co-ordinate frame relative to the
Survey+’s co-ordinate frame. It is important to get the orientation correct as although
settings entered on this page do not affect the accuracy of the Survey+, if the outputs
are not properly rotated to the vehicle frame then the measurements will appear
incorrect.
When using the RT-Strut the orientation will need to be changed. Figure 11 shows the
Survey+ mounted on an RT-Strut in a vehicle. In this configuration, the y-axis points
left and the z-axis points forwards. Other configurations are possible with the RT-Strut.
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Figure 11. Survey+ mounted on RT-Strut
The front panel label of the Survey+, seen in Figure 4 on page 24, shows the axes and
directions relative to the system for easy reference while configuring it. The Orientation
page of the configuration wizard, shown in Figure 12, also has illustrations to visualise
the orientation of the Survey+ in a vehicle based on the settings input.
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Figure 12. NAVconfig Orientation page
To work out the direction that the Survey+ is mounted at, look to see which directions
the y-axis and the z-axis are pointing and select these directions from the drop-down
lists. The greyed out advanced settings will change to show the three rotations
associated with orientation chosen.
To make small adjustments use the advanced settings. This allows the user to ‘zero’
any heading, pitch or roll offsets.
For correct initialisation it is also necessary to get the heading orientation correct. The
Survey+ gets its initial heading by assuming that the vehicle is travelling forwards in a
straight line. If the definition of the vehicle’s x-axis (forward direction) is incorrect in
the Survey+ then it will not initialise correctly when the vehicle drives forwards.
Get improved settings
Also included on the Orientation page is the ability to read the configuration settings
from a warmed-up system. While the Survey+ is running it tries to improve some of its
configured parameters. This option is useful if a calibration run has been done and the
Kalman filter’s values are known to be good.
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In particular the Survey+ will try to improve the GNSS antenna position, the
orientation of the dual antennas, the yaw orientation of the Survey+ in the vehicle and,
if one is being used, the odometer calibration values. In applications where the Survey+
is permanently installed in a vehicle it can be beneficial to import these improved
values into the Survey+’s configuration file to be used next time. It can make the
results more consistent. However, this feature should not be used if there is a risk the
Survey+ will rotate in the vehicle or that the GNSS antennas can move – even by a few
millimetres.
To read the improved values from the Survey+, click the Get improved settings button
on the Orientation page to open the Get settings from Survey+ window, as shown in
Figure 13.
Figure 13. Source selection to get improved configuration
Click the drop-down list and choose which source to read the configuration from. The
two options are:

Read configuration from file. If an NCOM file has been saved to disk, or
processed using the post-process utility then this file can be read and the settings
extracted from it. Use this setting if you have an NCOM file. Click Browse…
and select the NCOM file you wish to read the configuration from. Do not use an
NCOM file that has been combined from forward and backwards processing of
the inertial data.

Read configuration from Ethernet. This will get the information that the Survey+
is currently using and apply it next time the Survey+ starts. Use this setting if the
Survey+ is running, has initialised and has warmed up. Select the correct IP address
of the Survey+ to read the configuration from in the drop-down list. Note: the list
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will not function correctly if NAVdisplay or other software is using the Survey+
UDP port unless the OxTS UDP Server is running.
Once the source has been selected, click Next and the software will find which settings
can be obtained from the source. Settings that cannot be obtained will be shown in
grey; this may be because the Survey+ is not calculating these values at present. Figure
14 shows the Settings page with the parameters available to improve in the
configuration.
You may update several parameters at once. Select the settings you want to be updated
and uncheck the ones that you do not want to update. Click Finish to transfer these
settings to the configuration wizard.
Figure 14. Select which settings to update for improved configuration
If Orientation in vehicle is selected then this has consequences for other
measurements that have already been entered into NAVconfig. For example, if the
orientation in the vehicle has been changed then it is not clear whether the primary
GNSS antenna should be rotated or not. In general NAVconfig will rotate the
configurations that the Kalman filter can derive (primary antenna lever-arm and
secondary antenna orientation) but it will not change the user measured configurations
(wheel config, odometer input).
The improvement to orientation should only be applied if the change in the orientation
is small (less than 5°). If the change in orientation is large then it is likely that the
original configuration was wrong or has not been loaded into NAVconfig. You are very
likely to get poor results if the orientation is changed by a large amount.
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Primary antenna position
The Survey+ can calculate the position of the primary antenna itself. However, this
takes time and better results can be achieved sooner if the user measures the distance
accurately. Getting these measurements wrong is one of the main reasons for poor
results from the Survey+, so it is important to be careful. It is recommended to measure
the GNSS antenna position to an accuracy of 10 cm or better.
Figure 15 shows the Primary Antenna page.
Figure 15. NAVconfig Primary Antenna page
It is necessary to tell the Survey+ the distance between its measurement origin (shown
in Figure 5 on page 28) and the GNSS antenna’s measurement point. This should be
entered in the vehicle’s co-ordinate frame.
The accuracy of the measurements should also be specified, and care should be taken
here. It is very easy to measure within 1 cm or better in a straight line, but it is much
harder to measure within 1 cm through a vehicle roof. This is compounded if the
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Survey+ is slightly misaligned in the vehicle. Any alignment errors should be included
in the accuracy you believe you can measure to.
Telling the Survey+ you have measured the distances within 5 mm may lead the
Survey+ to believe its results are better than they really are. You may be impressed by
the accuracy the Survey+ reports, but in reality it will not be that accurate. It is better to
overestimate the accuracy (i.e. tell the Survey+ a worse value) than to underestimate it.
The Survey+ will try to improve the position of the primary GNSS antenna during use.
To use the values the Survey+ has estimated use the Get improved settings utility on
the Orientation page. More information on improving the configuration settings can be
found on page 41.
Secondary antenna position
If a Survey+2 option was selected on the Product Selection page, then the Secondary
Antenna page (Figure 16) will be available to configure the position of the secondary
antenna relative to the primary antenna. Click the Enable secondary antenna
checkbox to allow the configuration to be entered. If it is not enabled, the Survey+2
will ignore the secondary antenna and will not use it to compute a heading solution.
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Figure 16. NAVconfig Secondary Antenna page
By default the Antennas are level box is checked. This means the antenna baseline
should be within 15° of horizontal. When the antennas are level the separation should
be measured to within 5 cm. If the antennas are not level, i.e. mounted with height
offsets or on an incline, then the box should be unchecked. In this case, the separation
should be measured to within 5 mm.
Enter the antenna separation and select to position of the secondary antenna relative to
the primary antenna from the drop-down list. The illustrations will change according to
the settings you choose to help visualise the configuration of the antennas.
If the antennas are mounted at significantly different heights, or if the mounting angle
is not directly along a vehicle axis (forward or right), then click the Edit advanced
settings checkbox to enable advanced settings and specify the orientation and height
offset.
Getting the angle wrong by more than 3° can lead the Survey+2 to lock on to the wrong
heading solution. The performance will degrade or be erratic if this happens. If the
angle between the antennas cannot be estimated within a 3° tolerance then contact
OxTS support for techniques for identifying the angle of the antennas.
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The Enable static initialisation option is useful for slow moving vehicles or when
dynamic initialisation may be difficult. Static initialisation is 99% reliable in open sky,
but the reliability decreases in environments with high multipath. Static initialisation is
also faster when the antenna separation is smaller and the Antennas are level checkbox
is ticked.
The static initialisation algorithms degrade rapidly in non-ideal conditions. They should
only be used in open sky environments. Using a shorter separation can improve the
accuracy in non-ideal conditions.
Wheel configuration
The Wheel configuration feature uses characteristics of land vehicle motion to improve
heading and reduce drift. Specifying the position of the non-steered wheels makes a
huge difference to the lateral drift performance of the Survey+ when GNSS is not
available. The vertical drift performance can also be improved by specifying some
additional measurements.
This feature must be disabled for airborne and marine applications where the lateral
velocity can be significant. It is also not suitable for land vehicles that have no nonsteered wheels. The vertical settings should not be used if the vehicle can perform
wheelies.
The Survey+ uses the position of the non-steered wheels to reduce the lateral drift when
GNSS is not available and to improve the heading accuracy. The Wheel configuration
feature applies heading correction when the vehicle is not slipping; when the vehicle is
slipping the lateral acceleration is usually large enough that the normal heading
corrections provide excellent results. When combined with an odometer input (see
“Odometer input” on page 52) the drift of the Survey+ when GNSS is not available is
drastically reduced.
Figure 17 shows the Wheel Configuration page.
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Figure 17. NAVconfig Wheel Configuration page
For the Lateral settings, the system needs to know the position of the non-steered axle
(rear wheels on a front-wheel steering vehicle and vice versa). Vehicles with all wheels
steering cannot use this feature reliably, although minor steering of the rear-wheels
does not significantly affect the results. A position at road height, mid-way between the
rear wheels should be used, see Figure 18.
Figure 18. Position of road surface at centre of rear wheels
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Measure the distances to the non-steered axle position from the Survey+ in each axis in
the vehicle co-ordinate frame. Select the direction from the drop-down lists and enter
the distances.
Typically all measurements should all be made to an accuracy of 10 cm. Selecting an
accuracy better than 10 cm does not improve results. Using an accuracy figure worse
than 20 cm will increase the drift of the Survey+. Use the accuracy fields to select or
specify the accuracy of the measurements.
The Wheel configuration feature also requires some knowledge of the road surface.
Select one of the predefined options from the drop-down list, Normal or Low friction
(ice).
For the Vertical settings, the system needs to know the position of the front axle. A
position at road height, mid-way between the wheels should be used, like for the rear
axle.
Measure the distances again from the Survey+ and enter them into the cells, selecting
the appropriate directions from the drop-down lists.
Options
The Options page includes some important settings for getting the best results from
your Survey+ system. Figure 19 shows the Options page of the configuration wizard.
To adjust the settings, click the default value in the Setting column to activate the cell.
A description on each option and how to adjust it is found below.
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Figure 19. NAVconfig Options page
Vehicle starts
Adjustment: select a predefined value from the drop-down list.
If you know the vehicle will be level when starting (to within about 5°) select Level.
This saves about 40 s during the initialisation process since the Survey+ does not have
to take the time to compute an initial roll and an initial pitch. In high vibration
environments Not Level may not work and so the Survey+ can only start if the vehicle
is level and the Level option has been specified.
Initialisation speed
Adjustment: select a predefined value from the drop-down list or type in a value.
If static initialisation (see “Secondary antenna position” section) has not been enabled,
the Survey+ will need to be initialised by driving forwards in a straight line to initialise
the heading to the track angle. The initialisation speed is the speed at which the vehicle
must travel to activate the initialisation.
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The default initialisation speed for the Survey+ is 5 m/s. However, some slow vehicles
cannot achieve this speed. For these vehicles adjust the initialisation speed to a
different value.
If a speed less than 5 m/s is selected then care should be taken to make sure that the
Survey+ is travelling straight when it initialises.
Camera trigger
Adjustment: select a predefined value from the drop-down list or type in a value.
The Survey+ can generate a regular pulse based on distance; for example, one pulse
every 10 m of travel. This can be used to trigger a camera so that a picture can be taken
on a regular basis.
Enter the distance between pulses or leave disabled (default).
GNSS weighting
Adjustment: select a predefined value from the drop-down list.
The Survey+ can place different emphasis on the GNSS receiver’s measurements. The
default setting is Medium, placing equal weighting on the GNSS receivers and inertial
sensors. Selecting High will cause the Survey+ to believe the GNSS receivers more
and selecting Low will make the Survey+ rely more on the inertial sensors.
In urban environments it is better to believe the inertial sensors more whereas in open
sky the GNSS receiver should be believed more.
Heading lock
Adjustment: select a predefined value from the drop-down list.
The heading of the single antenna Survey+ can drift when it remains stationary for long
periods of time. To solve this, the Survey+ includes an option to lock the heading to a
fixed value when stationary. This option cannot be used if the vehicle can turn on the
spot (e.g. on a boat). With heading lock enabled the Survey+ can remain stationary for
indefinite periods of time without any problems.
There are four settings to choose from. Disabled should be selected if the vehicle can
turn on the spot. The default setting Normal is best for most applications as it is least
likely to cause problems in the Kalman filter. Tight and Very tight are better when
trying to reduce position drift in poor GNSS environments and traffic jams.
Table 19 gives a more detailed description on each of the heading lock options.
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Table 19. NAVconfig heading lock options
Heading lock
Description
Normal
This option assumes that the heading of the vehicle does not change by more than
2° while the vehicle is stationary. The heading accuracy recovers quickly when the
vehicle moves.
Tight
This option assumes that the heading of the vehicle does not change by more than
0.5° while the vehicle is stationary. The recovery is fast if the heading of the
vehicle does not change but will be slow if the vehicle turns before it moves.
Very tight
The option assumes that the heading of the vehicle does not change by more than
0.3° while the vehicle is stationary. The recovery is fast if the heading of the
vehicle does not change but will be slow if the vehicle turns before it moves. This
option can cause problems during the warm-up period if the vehicle remains
stationary for a long time and then drives suddenly.
Note: The heading of most vehicles does change if the steering wheel is turned while the vehicle is
stationary. Junctions and pulling out of parking spaces are common places where drivers turn the steering
wheel while not moving.
Displace output
Adjustment: click … button to open properties window.
The Survey+ can displace or move its outputs to another location in the vehicle. This
simulates the Survey+ being mounted at the new location, rather than at its actual
location. This function displaces all of the outputs (position, velocity, acceleration) to
this new location.
To enable output displacement, click the checkbox in the properties window and enter
the offsets to the new location in the vehicle. The offsets are measured from the
Survey+ in the vehicle co-ordinate frame. Select the directions from the drop-down
lists.
Note that the noise in the acceleration outputs will be much higher when output
displacement is used. Typical installations in moving vehicles have angular vibrations
of about 2 rads/s²; this equates to 2 m/s² of additional vibration of a 1 m output
displacement. It will be necessary to filter the data if Displace output is used.
Odometer input
Adjustment: click … button to open properties window.
Using an odometer input makes a huge difference to the longitudinal drift performance
of the Survey+ when GNSS is not available. It is essential to use the Wheel
configuration feature (page 47) at the same time as an odometer input.
As with the Wheel configuration feature, the odometer input can only be used on land
vehicles; aircraft and marine vehicles cannot use this option. The odometer must not be
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used on a steered wheel, it must be used on a wheel that is measuring the forward
direction of the vehicle.
Figure 20 shows the Odometer input properties window. To enable the odometer input,
ensure the checkbox is checked. If this option is disabled, the Survey+ will ignore
corrections from the odometer even if it is connected.
Figure 20. NAVconfig Odometer input properties window
The distances from the Survey+ to the measurement point of the odometer in the
vehicle co-ordinate frame should be input. The directions can be selected from the
drop-down lists. If the odometer is from a prop shaft then the distance should be
measured half way between the two wheels. The illustrations in the window will
change depending on the settings you choose, to help visualise the position of the
Survey+ in relation the odometer.
Ideally the measurements would be made to an accuracy of 10 cm. Using higher
precision for the measurement does not improve the results. Using an accuracy figure
worse than 20 cm will increase the drift of the Survey+. The accuracy can be specified
as the same for all measurements using Overall accuracy or it can be specified for
each individual measurement by clicking the Specify each accuracy separately
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checkbox. In either case, choose a predefined value from the drop-down list or type in a
value.
Enter the pulses per metre of the odometer. A value that is accurate to 10% is sufficient
unless the figure is known more accurately. The Survey+ will improve this scaling
factor itself when GNSS is available. The Improve configuration utility can be used to
apply a more accurate value calculated by the Survey+ from a calibration run. If this
option is used then the Survey+ should be allowed to recalibrate the scaling value
occasionally to account for tyre wear. See page 41 of this manual for more information
on improving the configuration.
The odometer corrections will not be as effective in reducing the drift of the Survey+ if
the odometer is measuring two wheels (i.e. after a differential), since the actual position
of the wheel is required for accurate navigation. If a post-differential encoder must be
used then the accuracy cannot be guaranteed.
For best results, a front wheel drive vehicle should be used with the odometer on a rear
wheel. The odometer pulses from driven wheels are less accurate.
Serial 1 and Serial 2 outputs
Adjustment: click … button to open properties window.
The Serial 1 and Serial 2 output ports can be configured for different message types.
Figure 21 shows the properties windows for the Serial 1 output, which are the same for
Serial 2.
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Figure 21. NAVconfig Serial output properties windows
Note: NMEA tab only appears when NMEA is selected from the Packet drop-down list.
Select the message type to output from the Packet drop-down list and select the baud
rate and data rate to output at. Table 20 gives details of the different messages.
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Table 20. Serial output options
Option
Description
Disabled
The serial output is disabled. This option can be used to reduce the computational
load and ensure that the Kalman filter runs quicker.
NCOM
Normal output of the Survey+. NCOM data is transmitted at up to 100 Hz or 125 Hz
(for 250 Hz systems; RS232 does not support 250 Hz). The format is described in
the NCOM Description Manual. Software drivers exist for decoding the NCOM
data.
IPAQ
NCOM output at a reduced rate. The baud rate of the serial port is set to 19200 and
the update rate is 25 Hz. It is used because the IPAQ cannot manage to receive the
data reliably above 25 Hz.
IPAQ+
NCOM output at a reduced rate and polled. Windows Mobile 5 on IPAQs crashes if
the Survey+ is sending data when the IPAQ is turned on. Using IPAQ+ the IPAQ
will poll the Survey+; the Survey+ will not send data while the IPAQ is off,
preventing the turn-on crash of the IPAQ.
NMEA
The NMEA outputs conform to the National Marine Electronics Association
Standard (NMEA 0183 version 3.01). The NMEA sentences available are GPGGA,
GPHDT, GPVTG, GPZDA, GPGST, PASHR, GPRMC, GPGSV, GPGSA, PTCF,
GPPPS, PRDID, GPROT, GPGGK, and GPUTC. The NMEA 0183 description
manual gives details of the fields output in the NMEA sentences.
Javad I+RTK
A special set of messages output in GREIS format to be used with Javad receivers.
For assistance please contact OxTS for support.
MCOM
TSS1
TSSHHRP
Used for marine applications. Identical to NCOM output but with the addition of
heave measurements.
TSS1 format outputting acceleration, heave, roll and pitch.
TSSHHRP format.
EM3000
Suitable for use with Simrad EM3000 multibeam sounders.
EM1000
Suitable for use with Simrad EM1000 multibeam sounders.
If the NMEA packet type is selected, the NMEA tab will appear in the properties
window (see Figure 21). In this tab the NMEA messages to output on the serial port of
the Survey+ are selected by choosing the data rate for each message type from the
drop-down lists and clicking the checkbox for when to generate the message.
NMEA messages can be generated by falling or rising voltages on the event inputs.
Check the falling or rising edge checkbox to compute the message when the event
occurs. The Survey+ can also generate NMEA messages from pulses on the camera
trigger. These messages use interpolation to compute the values at the exact time of the
event and may be output on the serial port up to 30 ms late and out of order compared
to the normal messages. To enable these messages check the appropriate checkbox.
Note that it is easy to overload the serial port if there are too many events. The software
computes the number of characters that will be output each second and displays this at
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the bottom of the window. A serial port data overflow warning message will appear if
the data rate is too high for the selected baud rate; to fix this it is necessary to lower the
data rate of the selected NMEA sentences or increase the baud rate.
Selecting Allow extended length messages enables the full GGA and RMC messages
to be output, which are longer than the NMEA specification allows. Please see the
NMEA 0183 Description manual for more details.
Selecting Output approximate values before initialisation forces output of the raw
GNSS measurements before the Survey+ is initialised. Currently just the position is
output and this is the position of the antenna, not the inertial measurement unit. Note
that there will be a jump (from the antenna to the inertial measurement unit) when
initialisation occurs.
Ethernet output
Adjustment: click … button to open properties window.
The Ethernet output of the Survey+ can be configured for different data rates and
delays. Figure 22 shows the Ethernet output properties window.
Figure 22. NAVconfig Ethernet output properties window
The Ethernet output can either output NCOM or MCOM, or be disabled by using the
Output Packet drop-down list. When NCOM or MCOM is selected, the Data rate can
be selected by using the drop-down list.
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The Survey+ can output Ethernet messages when an event (rising or falling edge) is
input on the event input pin. It can also output Ethernet messages from pulses in the
camera trigger. These messages are interpolated to the time when the event occurred
and may be output up to 30 ms late and out of order compared to the normal messages.
It is essential to enable these options if the events have a rate higher than 1 Hz,
otherwise the output cannot communicate all of the events and some will be lost.
The Delay output option should not be used with the Survey+.
Output smoothing
Adjustment: click … button to open properties window.
When the Kalman filter in the Survey+ determines that there is some error to correct,
this error is applied smoothly rather than as a jump. The output smoothing controls how
fast the correction is applied to the outputs.
Figure 23 shows the Output smoothing window. Click the checkbox to enable output
smoothing and unlock the properties for editing.
Figure 23. NAVconfig Output smoothing properties window
The smoothing of the position, velocity and orientation corrections can be controlled
independently. Enter the maximum correction that can be applied every second. For
example, if 0.1 m is entered for the position smoothing then the Survey+ will only
correct a position error by a maximum rate of 0.1 m/s.
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If a large error is accumulated (for example, if GNSS is not available for a long period
of time) then it may take a very long time to apply the correction. Under these
circumstances it may be preferable to “jump” the measurement to the correct value
quickly. By specifying a time in the Time limit section for the correction, the Survey+
will jump the measurement if it will take too long to correct.
For example, if the position has drifted by 5 m after a period without GNSS and the
smoothing is set to 0.05 m then it will take at least 100 s to correct the 5 m drift. If the
time limit is set to 20 s then the Survey+ will apply the 5 m correction immediately
because the predicted time to correct the position is longer than the time limit.
Care should be taken not to make the smoothing too small. If these parameters are too
small then the Survey+ will not be able to make suitable corrections to the outputs and
it will not work correctly.
Note: this function is designed to improve the data in real-time. When post-processing
the data using the forwards-backwards combined option, output smoothing should not
be used as it may give unexpected results.
GNSS control
Adjustment: click … button to open properties window.
The GNSS control option contains advanced options that control how the GNSS
information is managed in the Survey+. The GNSS algorithm tab can be used to select
the algorithm used for merging the GNSS and the inertial data in the Kalman filter. The
Recovery tab can be used to decide how to begin using GNSS measurements if they
have been rejected or ignored for a period of time.
Figure 24 shows both tabs in the GNSS control properties window.
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Figure 24. NAVconfig GNSS control properties window
The GNSS algorithm tab gives a choice of two algorithms for computing the GNSS
measurements. The default option is to use the algorithm provided by the GNSS
receiver. Using this algorithm the Survey+ will accept position and velocity from the
GNSS and use it to update the Kalman filter.
The gx/ix raw data processing algorithm uses the raw data from the GNSS and custom
algorithms to compute position and velocity tailored to the needs of the Kalman filter.
It also improves performance in poor GNSS environments using single satellite aiding
technology and tightly coupled GNSS and inertial measurements. Gx/ix mode is
recommended to achieve the highest accuracy in environments where RTK lock may
be difficult to maintain, e.g. urban canyons.
Note: gx/ix processing is a new technology and is still being developed and improved.
As such there are some limitations to its compatibility. Table 21 details the current
compatibilities of gx/ix mode.
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Table 21. gx/ix compatibility
GNSS mode
Real-time
Post-process
SPS


SBAS
x
x
DGPS


RTK
x
With gxRTK upgrade
GLONASS
x
x
Note: only RTCM V3 format differential corrections are supported in gx/ix mode.
The Recovery tab controls how the Survey+ will accept or reject GNSS measurements.
The Survey+ will automatically reject GNSS updates that it believes are not correct.
However, there is a limit on the number of GNSS measurements that the Survey+ will
reject. Once this limit has passed the Survey+ accepts the GNSS update since it is
possible the GNSS is correct and the inertial measurements are not. The GNSS control
determines how many updates the Survey+ should ignore before forcing the GNSS to
be accepted. Both the velocity and the position can be controlled separately.
In the default state the Survey+ will reject up to 20 GNSS measurements before it
forces the GNSS to be accepted. However, in high multipath environments or when
odometer measurements are used, it may be desirable to reject more GNSS
measurements. Select the Start believing measurements after_ option and enter the
number of GNSS measurements to reject before the system starts believing it again.
The Survey+ GNSS receivers update both position and velocity at a rate of 5 Hz.
Therefore to ignore updates for 60 s for example, the number to enter to start believing
measurements again would be 300.
Coordinate system
The Survey+ can output position relative to different coordinate frames. Click the
button to open the properties window, shown in Figure 25.
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Figure 25. NAVconfig coordinate system properties window
From the Coordinate datum section you can choose which reference datum to output
latitude and longitude relative to. The default system and the standard for GPS is the
WGS 84 datum.
Note: Currently outputs will only reference datums other than WGS 84 in postprocessing. Real-time outputs will still be referenced to WGS 84 even if another option
is selected.
The Altitude reference can be compared to either ellipsoidal or geoidal height. If
Ellipsoid is selected, the altitude will be output with respect to the reference ellipsoid
selected in the coordinate datum section. If Geoid (receiver default) is selected, the
altitude will be relative to the geoid used in the GNSS receivers. A Custom geoid file
can be used for local variations. To download supported geoid files, go to
http://support.oxts.com/local-geoid-files/. The *.ugf file must be saved in
C:\Users\username\Documents\OXTS\Shared\Custom geoid files. Once the file is
downloaded and saved in this location, it can be selected from the dropdown box.
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A constant offset to the specified altitude reference can be applied by checking the Set
offset box typing in a value into the cell.
Output lock
Adjustment: select a predefined value from the drop-down list.
The output of the Survey+ will continue to change even when the vehicle is stationary.
For some video systems this leads to ambiguous results. The position and orientation
can be “locked” by the Survey+ automatically when the vehicle becomes stationary.
While the outputs are locked, the Kalman filter continues to run and accumulate errors.
When the vehicle moves, the Kalman filter will quickly return to the new solution. The
drift rate can be controlled using the Output smoothing option.
Differential correction
Adjustment: click … button to open properties window.
The Survey+ can be configured to use several different differential correction message
types on connector J3. Figure 26 shows the Differential corrections properties window.
Table 22 gives details on the different correction types available.
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Figure 26. NAVconfig Differential corrections properties window
Table 22. NAVconfig differential correction types
Correction type
RTCA
RTCA is the standard adopted for aircraft. It was the first open standard to use
2 cm corrections. The RT-Base and GPS-Base products use RTCA.
RTCM
RTCM is the most common open standard used for differential corrections. Old
implementations of RTCM did not support 2 cm corrections, which is why Oxford
Technical Solutions uses RTCA by default. New models support 2 cm corrections
over RTCM.
RTCM V3
RTCM V3 is the latest version of RTCM. This option gives the best accuracy and
should be used if your differential corrections are in Version 3 format.
CMR
This is a standard adopted by Trimble. The Survey+ products support both CMR
and CMR+ formats.
Advanced
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Description
This option is reserved.
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Select the Correction type you wish to use from the drop-down list and then select the
Baud rate. The most common baud rates used for differential corrections are 4800
baud and 9600 baud. The RT-Base and GPS-Base use 9600 baud.
When checked, the NTRIP option sends an NMEA GGA message out from J3 back to
the NTRIP server.
The Networked DGPS controls allow a Survey+ to be configured to broadcast or
receive differential corrections over Wi-Fi when connected to an RT-XLAN. When
Network correction transmitter is selected, an RT will broadcast differential
corrections it is receiving via a radio modem from an OxTS base station, using its RTXLAN. Other Survey+ devices that are on the same network as the broadcasting RT,
will then be able to receive the DGPS messages and use them. To do this, the Network
correction receiver option should be selected on those devices, and the IP address of
the system carrying the radio modem should be selected from the box. Using this
system reduces complexity in situations where multiple devices need DGPS corrections
as only one pair of radio modems needs to be used.
Networked DGPS can also use corrections received via NTRIP, rather than a local base
station. As before, the Survey+ that is connected to the NTRIP server should be
configured with Network correction transmitter selected. Other devices should be
configured with Network correction receiver selected, and the IP address of the system
that is configured as the transmitter should be selected in the box.
Regardless of whether DGPS corrections are received via NTRIP or a local base
station, only RTCMv3 corrections are currently supported in networked DGPS mode.
SBAS
Adjustment: select a predefined value from the drop-down list.
In Europe, North America, and Japan SBAS can be used for differential corrections.
These services will improve the position accuracy of the Survey+. In North America
the SBAS service is known as WAAS, in Europe it is known as EGNOS and in Japan it
is known as MSAS. Select the option that is most suitable for the territory you are in.
DGNSS service
Adjustment: click … button to open settings window.
Select either Automatic or Manual from the corrections drop-down list in the
properties window to enable corrections.
When manual is used, the correct satellite should be selected for the region where you
are operating.
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Several satellites have been pre-programmed into the software. In the future more
satellites may exist, or their properties may change. In this case it is necessary to select
Use advanced settings to set the satellite’s Frequency and Baud rate.
Advanced
Adjustment: click … button to open settings window.
The Advanced option is used to set special commands for the Survey+. This should
only be done with special instructions from OxTS.
Committing the configuration to the Survey+
Changes to the Survey+ settings must be sent using Ethernet. It is necessary to
configure your computer’s Ethernet settings so it is on the same network as the
Survey+. The section “Ethernet configuration” on page 30 gives details on how to do
this.
Figure 27 shows the Commit page.
Figure 27. NAVconfig Commit page
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Enter the IP address of the Survey+ that you want to configure or select it from the
drop-down list. The drop-down box will list all of the systems that are connected to the
computer’s network so ensure to select the correct system if there are multiple listed.
The list will not work if NAVdisplay or other software is using the Survey+ UDP port
unless the OxTS UDP server is running.
Press Commit to save the configuration in the Survey+. This will automatically reset
the Survey+ so the changes take effect. It will be necessary to initialise and warm-up
the Survey+ again after the changes have been applied.
Saving the configuration and finishing
Before finishing it is possible to save a copy of the configuration in a folder on your
computer. This can then be loaded next time. The Save/Finish page also lets you know
if the settings have been committed successfully or not. Figure 28 shows the
Save/Finish page.
Figure 28. NAVconfig Save/Finish page
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To save a copy of the configuration in a local folder check the Save settings in the
following folder box and use Browse… to select a folder. The configuration has a
number of files associated with it so it is recommended to create a new folder. Click
Finish to save the configuration to the selected folder and close NAVconfig.
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Initialisation process
Before the Survey+ can start to output all the navigation measurements, it needs to
initialise itself. In order to initialise, the Survey+ needs all the measurements listed in
Table 23.
Table 23. Quantities required for initialisation
Quantity
Description
Time
Measured by internal GNSS.
Position
Measured by internal GNSS.
Velocity
Measured by internal GNSS.
Heading
Approximated to course over ground (with large error) when the vehicle moves. Dual
antenna models have the option for static initialisation which does not require any
movement.
Roll, pitch
Estimated over first 40 s of motion with large error.
The system will start when it has estimates of all of these quantities. Course over
ground will be used as the initial heading when the system exceeds the value set as the
initialisation speed unless static initialisation has been selected for a dual antenna
system. The system takes about 40 s to find approximate values for roll and pitch.
For the initialisation process to work correctly, the Survey+ requires the user to tell it
which way it is mounted in the vehicle, otherwise the course over ground will not be
close enough to the heading.
Real-time outputs
During the initialisation process the system runs 1 s behind, allowing GNSS
information to be compared to information from the inertial sensors. After initialisation
the system has to catch-up from this 1 s lag. It takes 10 s to do this. During the first 10 s
the system cannot output data in real-time, the delay decays to the specified latency
linearly over this 10 s period.
The system turns the SDNav LED orange to show the outputs are not real-time. When
the system is running in real-time this LED is green.
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Warm-up period
During the first 15 minutes of operation the system will not conform to specification.
During this period the Kalman Filter runs a more relaxed model for the sensors. By
running a more relaxed model the system is able to:
1. Make better estimates of the errors in the long term (if it does not get these correct
then they become more difficult to correct as time goes on).
2. Track the errors in the inertial sensor during their warm-up period (when their
errors change more quickly than normal).
During this period it is necessary to drive the vehicle or the errors will not be estimated
and the specification will not be reached. The NCOM output message includes status
information that can be used to identify when the required specification has been met.
These are plotted in the example below.
The warm-up period is a concern to some customers but it is often very simple to
overcome. Below is an example of a good warm-up procedure that did not involve a lot
of work for the user. In this example the key features are:

The Survey+ was configured well—the GNSS antenna position, Wheel
configuration options and dual antenna separation were measured accurately in
advance.

The Survey+ was turned on as soon as possible. In this case it took us 15 minutes
to get all the other equipment sorted out. The Survey+ was stationary for most of
this period—which is not a problem.

Although in this example the Survey+ was receiving corrections from a basestation while stationary, it is not necessary. The base-station should be working
before the dynamic driving starts so the Survey+ can use the best information to
self-calibrate (if a base-station is not being use this does not apply).

There are 6 minutes during which the vehicle was driven in figures of eight. From
the graphs you can see the Survey+ is accurate almost after the first figure of
eight, after that the improvement is very small.
The trick is to turn the Survey+ on early, do not reconfigure it (which resets it) or cycle
the power.
Figure 29 shows the route driven and Figure 30 shows the accuracy estimated by the
Kalman filter for various output parameters during the first 25 minutes. The quality of
initialisation would have been the same if the stationary period was 10 minutes,
followed by 5 minutes of driving. The time on the graphs is the time from initialisation.
In this example the Survey+ was initialised 25 s after starting up; the quality of
70
Oxford Technical Solutions
Survey+ User Manual
initialisation would be the same if it had been not been initialised for the first 10
minutes, then initialised and driven for 5 minutes.
Figure 29. Example warm-up driving route
At the start there is just a small amount of motion to get the Survey+ initialised. During
this time the Kalman filter cannot improve the position accuracy because the position
of the GNSS antenna is not known accurately and cannot be estimated without motion.
The accuracy of the velocity, roll and pitch steadily improves as the Kalman filter
places more and more weight on the inertial sensors. At this point the heading accuracy
is worse than the scale of the graph ((d) in Figure 30); the heading is not accurate and
the dual antenna system cannot measure the angle of the GNSS antennas compared to
the inertial sensors, so the dual antenna cannot provide accurate information.
Just after 500 s the Survey+ is driven (it is the small loop on the east side in Figure 29,
not the figures of eight). This small amount of driving is sufficient for the Kalman filter
to gain confidence in the antenna position and to improve the alignment of the two
GNSS antennas compared to the inertial sensors. After this period the position accuracy
is better than 2 cm and the heading is better than 0.2°.
Revision: 150714
71
Figure 30. Example warm-up accuracy estimates
(a) Forward velocity. (b) Position accuracies. (c) Velocity accuracies. (d) Orientation accuracies.
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Oxford Technical Solutions
Survey+ User Manual
You can see the Survey+ is nearly at specification after just this small amount of
driving. However, experience tells us the Kalman filter will continue to make some
improvements (not obvious) during the first few figures of eight. The main part of the
motion occurs after 1100 s when the vehicle was driven in a figure of eight for 6
minutes.
These are fairly large figures of eight driven at relatively low speeds. Notice the brake
stops in the velocity graph ((a) in Figure 30) where the speed falls to zero. These are
important parts of the warm-up—so as many states in the Kalman filter as possible can
be updated.
Notice how close to the specification the Survey+ is even without the figure of eight
manoeuvres. Warm-up is recommended in order to achieve the highest level of
accuracy. In aircraft applications, flying figures of eight will remove a few hundredths
of a degree of roll and pitch error—which can be critical for geo-referencing
applications. The same is true for marine applications. However the effect is small and
only significant when you need the full performance of the Survey+.
Revision: 150714
73
Inputs and outputs
The Survey+ has one main connector for its inputs and outputs (label 6 on Figure 4).
The J1 connector of the Survey+ user cable connects to this and connectors J2-J7 of the
user cable provide connections for the inputs and outputs. The connector on the
Survey+ is keyed so the user cable must be correctly aligned for it to connect. The
Survey+ user cable drawing located at the back of this manual gives details on each
connector and the pin assignments.
Digital inputs and outputs
Table 24 describes each of the signals on the J5 digital I/O connector. A more detailed
explanation of each signal can be found below.
Table 24. J5 pin assignments - digital I/O
Function
Description
Digital 1
1PPS from GNSS receiver
Digital 2
Event input
Digital 3
Odometer input
Digital 4
Camera trigger
Digital 5
IMU sync output pulse (100 or 250 Hz)
Digital Ground
Ground
Digital Ground
Ground
Digital Ground
Reserved
Digital Ground
Reserved
1PPS output
The 1PPS output is a pulse from the GNSS receiver. The falling edge of the pulse is the
exact transition from one second to the next in GPS time. The pulse is low for 1 ms
then high for 999 ms and repeats every second.
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Survey+ User Manual
Figure 31. 1PPS waveform
The output is a low-voltage CMOS output, with 0.8 V or less representing a low and
2.4 V or more representing a high. No more than 10 mA should be drawn from this
output. Limited protection is provided on this output.
Event input
The event input can be used to time events, like the shutter of a camera or a brake
switch. The event input has a pull-up resistor so it can be used with a switch or as a
CMOS input. A low voltage requires less than 0.8 V on the input and a high voltage
requires more than 2.4 V on the input. There is no protection on this input (protection
circuitry would disturb the accuracy of the timing). Keep the input in the range of 0 V
to 5 V.
By default the maximum event rate is 1 Hz for 100 Hz products and 4 Hz for 250 Hz
products. This can be increased to 50 Hz by selecting one or both the Output on
falling edge of trigger and Output on rising edge of trigger check boxes on the
Ethernet output properties window. This is accessed from the Options page of the
configuration wizard (see “Ethernet output” on page 57 of this manual).
Trigger information can be found in status message 24 and 43, output over NCOM.
Odometer input
The odometer input accepts TTL pulses from an encoder on a single wheel. An encoder
from a gearbox should not be used, and simulated TTL pulses should not be used. The
timing of the odometer input pulses is critical and nothing should cause any delay in the
pulses.
The odometer input requires less than 0.8 V for a low pulse and more than 2.4 V for a
high pulse. Limited protection is provided on this input, however the input voltage
should not exceed 12 V.
The wheel that is used should not steer the vehicle. The Survey+ will assume that this
wheel travels straight.
Revision: 150714
75
Camera trigger
The camera trigger output generates a pulse for a fixed distance travelled. The
configuration software can change the number of metres travelled between pulses. The
output has 0.8 V or less for a low and 2.4 V or more for a high. There is no protection
on this output, no more than 10 mA should be used on this output.
IMU sync output pulse
The IMU (inertial measurement unit) sync output pulse is a 100 Hz or 250 Hz output
pulse synchronised to the IMU sample time. The output has a duty cycle of
approximately 50% and the falling edge is synchronised to the sample file of the data
from the IMU.
The IMU is already synchronised to GPS time so one of the pulses each second will
line up with the 1PPS output. This allows other systems to sample based on the timing
of the Survey+.
Reverse polarity protection
The Survey+ products have limited reverse polarity protection. Reversing the polarity
on the power inputs for short periods of time is unlikely to damage the product.
Causing a short circuit through the Survey+ will damage the product. A short circuit
will be created if the polarity is reversed and another connector has ground connected.
In this condition the ground input of the power supply will be connected to the positive
power supply; this causes a high current to flow through the circuits in the Survey+ and
it will damage several internal components.
If the fuse in the plug needs to be replaced then it should be replaced with the Littelfuse
model given in Table 25. If an alternative connector is fitted to the cable then an
appropriate 5 A, fast-blow fuse should be fitted.
Table 25. Replacement fuse
76
Parameter
Specification
Manufacturer
Littelfuse
Part number
0214005
Description
5 A torpedo type fuse
Dimensions
25 × Ø 6 mm
Voltage rating
36 V
Oxford Technical Solutions
Survey+ User Manual
Laboratory testing
There are several checks that can be performed in the laboratory to ensure that the
system is working correctly. The most fragile items in the system are the
accelerometers, the other items are not subject to shock and do not need to be tested as
thoroughly.
Accelerometer test procedure
To check that the accelerometers are working correctly, follow this procedure.
1.
Connect power and a laptop to the system.
2.
Commit a default setting to the Survey+ using NAVconfig, then run NAVdisplay.
3.
Click the Calibration button, then select the Navigation tab and ensure the x, y,
and z accelerations (values 19 to 21) are within specification when the Survey+ is
placed on a level surface in the orientations according to Table 26.
Table 26. Acceleration measurement specifications
Orientation
Acceleration measurement
x
y
z
Flat
Flat
Down
z-acceleration between –9.7 and –9.9 m/s²
Flat
Flat
Up
z-acceleration between 9.7 and 9.9 m/s²
Down
Flat
Flat
x-acceleration between –9.7 and –9.9 m/s²
Up
Flat
Flat
x-acceleration between 9.7 and 9.9 m/s²
Flat
Down
Flat
y-acceleration between –9.7 and –9.9 m/s²
Flat
Up
Flat
y-acceleration between 9.7 and 9.9 m/s²
This test is sufficient to ensure that the accelerometers have not been damaged.
Gyro test procedure
To check that the gyros (angular rate sensors) are working correctly, follow this
procedure:
Revision: 150714
77
1.
Use the default orientation configuration in NAVconfig.
2.
Connect power to the system, connect the system to a laptop computer and run
the visual display software (NAVdisplay).
3.
Rotate the Survey+ according to Table 27 and check that the angular rate
measurements occur.
4.
With the unit stationary, check that all the angular rates are within ±5°/s. (In
general they will be within ±0.5°/s, but the algorithm in the Survey+ will work to
specification with biases up to ±5°/s).
Table 27. Angular rate measurement specifications
Rotation
Angular rate measurement
x
y
z
+ve
Zero
Zero
x-direction should indicate positive rotation, others are small.
–ve
Zero
Zero
x-direction should indicate negative rotation, others are small.
Zero
+ve
Zero
y-direction should indicate positive rotation, others are small.
Zero
–ve
Zero
y-direction should indicate negative rotation, others are small.
Zero
Zero
+ve
z-direction should indicate positive rotation, others are small.
Zero
Zero
–ve
z-direction should indicate negative rotation, others are small.
It is hard to do a more exhaustive test using the angular rate sensors without specialised
software and equipment. For further calibration testing it is necessary to return the unit
to OxTS.
Note that the Survey+ is capable of correcting the error in the angular rate sensors very
accurately. It is not necessary to have very small values for the angular rates when
stationary since they will be estimated during the initialisation process and warm-up
period. This estimation process allows the Survey+ to go for long periods without
requiring recalibration.
Testing the internal GNSS and other circuitry
To check that all the internal circuits in the Survey+ are working correctly and that the
navigation computer has booted correctly, use the following procedure:
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Oxford Technical Solutions
Survey+ User Manual
1.
Connect power to the system, connect the system to a laptop computer and run
the visual display software (NAVdisplay).
2.
Use Table 28 to check that the status fields are changing.
Table 28. Status field checks
Field
Increment rate
IMU packets
100 or 250 per second, depending on product model.
IMU chars skipped
Not changing (but not necessarily zero).
GPS packets
About 20 per second (depending on system).
GPS chars skipped
Not changing (but not necessarily zero).
GPS2 packets1
GPS2 chars skipped
About 5 to 10 per second (depending on system).
1
Not changing (but not necessarily zero).
1
The GPS2 related fields will only increase for dual antenna systems.
These checks will ensure that the signals from the GNSS receivers and from the inertial
sensors are being correctly received at the navigation computer.
Revision: 150714
79
Using the orientation measurements
This section has been provided to clarify the definitions of heading, pitch and roll that
are output by the Survey+.
The Survey+ uses quaternions internally to avoid the problems of singularities and to
minimise numerical drift on the attitude integration. Euler angles are used to output the
heading, pitch and roll, and these have singularities at two orientations. The Survey+
has rules to avoid problems when operating close to the singularities; if you regenerate
the rotation matrices given below then they will be correct.
The Euler angles output are three consecutive rotations (first heading, then pitch and
finally roll) that transform a vector measured in the navigation co-ordinate frame to the
body co-ordinate frame. The navigation co-ordinate frame is the orientation on the
earth at your current location with axes of north, east and down.
If V n is vector V measured in the navigation co-ordinate frame and V b is the same
vector measured in the body co-ordinate frame the two vectors are related by:
V n C bn V b
cos (  )
sin(  ) 0
sin(  ) cos (  ) 0 
Vn
0
0
1
cos (  ) 0 sin(  )
0
1
0
sin(  ) 0 cos (  )
1
0
0
sin(  ) V
b
0 sin(  ) cos (  )
 0 cos (  )
where:
 is the heading angle;
 is the pitch angle and
 is the roll angle.
Remember – heading, pitch and roll are usually output in degrees, but the functions sin
and cos require these values in radians.
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Oxford Technical Solutions
Survey+ User Manual
Revision history
Table 29. Revision history
Revision
Comments
131008
Initial version.
140501
Removed OmniSTAR support.
140610
Updated to v2 systems. Added Survey+ L1.
150312
Added vertical advanced slip and coordinate frame configuration options.
150714
Updated for the Spring 2015 NAVsuite release.
Revision: 150714
81
Drawing list
Table 30 lists the available drawings that describe components of the Survey+ system.
Many of these drawings are attached to the back of this manual. Note that the ‘x’
following a drawing number is the revision code for the part. If you require a drawing,
or different revision of a drawing, that is not here then contact Oxford Technical
Solutions.
Table 30. List of available drawings
Drawing
Description
14A0007x
Survey+ system outer dimensions
14C0121A
Survey+ user cable
110-00012-601
G5Ant-2AMNS1 GNSS antenna
110-00148-601
G5Ant-42AT1 GNSS antenna
110-00150-601
G5Ant-52AT1 GNSS antenna
82
Oxford Technical Solutions
Oxford Technical Solutions
77 Heyford Park
Upper Heyford
Oxfordshire
OX25 5HD
www.oxts.com
© Copyright Oxford Technical Solutions, 2013
Confidential Information
50
76
120
The information in this document
is confidential and must not be
published or disclosed either wholly
or in part to other parties or used to
build the described components
without the prior written consent of
Oxford Te chnical Solutions.
0
10
20
30
Print Size:
A4
Scale:
1:2 (Half)
Units:
mm
Tolerances: X.X - 0.1
> 120
234
197
30
A
A
Material:
HE30 Alu
Finish:
Anodised
14Cxxxx
22
30
47
80
B
3rd Angle
Notes:
A – M4 x 10 Tapped Hole
B – 2mm dia x 3 hole
18
25
B
Projection:
User cable drawn to show space
required for the bend radius.
Date:
23/07/09
Part #:
14A0007A
Document:
Survey+ out dimensions
Sheet:
1 of 1
J1 Deutsch AS612-35SA
J2
J3
J4
J5
J6
J7
Hellerman
154-42-G
9-Way Male D-type and shell
FEC 1342694
15-Way Male D-type and shell FEC 1342696
9-Way Male D-type and shell
FEC 1342694
9-Way Female D-type and shell FEC 1342695
See notes
4-Way M12 Male Cable Assy
FEC 1889386
D-type Plug Crimp Contacts
FEC 1560032
D-type Socket Crimp Contacts FEC 1560034
Oxford Technical Solutions
Tail lengths for J2-J7 given by
L2-L7, from junction to connector face
J2
RS-232
2
3
5
Nav Data RS232 RX
J1-4
J1-3
Nav Data RS232 TX
J1-12
RS232 Common
77 Heyford Park
Upper Heyford
Oxfordshire
OX25 5HD
www.oxts.com
© Copyright Oxford Technical Solutions, 2013
Confidential Information
J3
Radio
1
7
8
9
11
14
15
+Supply
RS232 Common
Supply Return
Radio Data RX
Radio Data TX
+Supply
+Supply
J3-14
J1-16
J7-3
J1-7
J1-6
J7-1
J7-1
The information in this document
is confidential and must not be
disclosed to other parties or used
to build the described components
without the written permission of
Oxford Technical Solutions.
0
10
20
30
A4
Not to scale
mm
5mm
14C0121A
90mm
J4
Aux RS232
2
3
5
Aux RS232 RX
J1-10
J1-9
Aux RS232 TX
Aux RS232 Common J1-17
24mm
400mm
J5
Digital I/O
1
2
3
4
5
6
7
8
9
Digital 1
Digital 2
Digital 3
Digital 4
Digital 5
Digital Ground
Digital Ground
Digital Ground
Digital Ground
J1-11
J1-8 See manual for details
J1-15 of the signals on
J1-19 Digital 1 to Digital 5
J1-5
J1-18
J1-18
J1-18
J1-18
N/A
J6 is a RJ45 UTP patch lead
which is cut to length and
terminated at J1.
Wire Types:
J7-1, J7-3 16/0.2
All others 7/0.2
J1-13 & J1-20 Twisted pair
J1-14 & J1-21 Twisted pair
Cables outers braided and
connected to J1-22, J1 shell
and J7 shell (through cable
assembly braiding).
Please populate all unused
pins with empty crimps.
J6
Ethernet
L2
L3
L4
L5
L6
L7
300mm
300mm
300mm
300mm
300mm
300mm
1
2
3
6
Ethernet (ETX +)
Ethernet (ETX -)
Ethernet (ERX +)
Ethernet (ERX -)
J1-20
J1-13
J1-21
J1-14
All cable markers in White
Ensure that the cable legend
text precisely matches that
given in diagram.
30/08/13
J7
Power
1
2
3
4
Brown +Supply (10-25 Volts DC) J1-1
White
Sleeved and made safe
Blue
Supply Return
J1-2
Black
Sleeved and made safe
14C0121A
Survey+ User Cable
1 of 1
[17.30] 0.68 in
Oxford Technical Solutions
[21.96] 0.86 in
X,Y PHASECENTRE = 0
(CENTRE OF ANTENNA)
Z PHASE=
77 Heyford Park
Upper Heyford
Oxfordshire
OX25 5HD
www.oxts.co.uk
© Copyright Oxford Technical Solutions, 2011
(1:2)
Confidential Information
The information in this document
is confidential and must not be
published or disclosed either wholly
or in part to other parties or used to
build the described components
without the prior written consent of
Oxford Te chnical Solutions.
dia [68.81] 2.71 in
0
10
20
Print Size:
A4
Scale:
1:1
Units:
mm
30
Tolerances: 1mm
10-32 UNF - 2B
x 0.250 DP
Projection:
Notes:
GPS/GLONASS Antenna
SMA Connector
magnetic
2cm
OmniStar
NAME PLATE
( 1 :2 )
[62.74] 2.47 in
3rd Angle
4x MAGNETS (FLUSH)
Date:
3x6-32 UNC - 2B
90°APART
(FOROPTIONAL MOUNTING)
06/05/11
Part #: 110-00012-601
Document:
G5Ant-2AMNS1
Sheet:
1 of 1
Oxford Technical Solutions
[119.38] 4.70 in
[40.64] 1.60 in
© Copyright Oxford Technical Solutions, 2013
Confidential Information
The information in this document
is confidential and must not be
published or disclosed either wholly
or in part to other parties or used to
build the described components
without the prior written consent of
Oxford Te chnical Solutions.
[76.20] 3.00 in
[83.82] 3.30 in
77 Heyford Park
Upper Heyford
Oxfordshire
OX25 5HD
www.oxts.com
[22.81] 0.90 in
0
X,YPHASECENTRE= 0
(CENTREOFANTENNA)
Z PHASE=
4xdia 5.11 THRU
dia 9.78 X 100°
[10-32 MTGSCREWS]
10
20
Print Size:
A4
Scale:
1:2
Units:
mm
30
Tolerances: 1mm
Projection:
3rd Angle
[14.53] 0.57 in
[5.99] 0.24 in
TNC
NAMEPLATE
TSO
NAMEPLATE
'O' RING
[6.48] 0.26 in
[3.76] 0.15 in
[18.14] 0.71 in
Notes:
* L1/L2/L5 GPS/GLO.
* OmniStar
* Precision carrier phase
* Suitable for 2 cm
products
* Typically for aircraft
* TNC Connector
* ARINC Form Factor
* Must be mounted on a
metal surface for
optimum performance
5V, 35dB Gain
Weight 227g
Date:
06/05/11
Part #: 110-00148-601
Document:
G5Ant-42AT1
Sheet:
1 of 1
Oxford Technical Solutions
12x [4.75] 0.187in THRU
EQUI SPCD 4.676in PCD
77 Heyford Park
Upper Heyford
Oxfordshire
OX25 5HD
www.oxts.com
© Copyright Oxford Technical Solutions, 2013
Confidential Information
TAPERULESHOOK
The information in this document
is confidential and must not be
published or disclosed either wholly
or in part to other parties or used to
build the described components
without the prior written consent of
Oxford Te chnical Solutions.
[8.51] 0.34 in
0
X,YPHASECENTRE= 0
(CENTREOFANTENNA)
Z PHASE=
dia [127.00] 5.00 in
10
20
Print Size:
A4
Scale:
1:2
Units:
mm
30
Tolerances: 1mm
[42.66] 1.68 in
[29.49] 1.16 in
dia [66.04] 2.60 in
[1.57] 0.06 in
[10.44] 0.41 in
Projection:
Notes:
* L1/L2/L5 GPS /GLO.
* OmniStar
* Precision carrier phase
* Suitable for 2 cm
products
* TNC Connector
* Mount on survey poles
UNC 5/8"-11 Thread
Alternative mounting
4x 6-32 UNC-2B
5V, 35dB Gain
Weight 250g
NAME PLATE
5/8-11 UNC- 2B
3rd Angle
Date:
06/05/11
Part #: 110-00150-601
4x6-32 UNC- 2B
X 0.250 DP
EQUI SPCD58.57[2.31in] PCD
Document:
G5Ant-52AT1
Sheet:
1 of 1
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