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GPSG-1000
GPS/Galileo
Positional Simulator
Operation Manual
EXPORT CONTROL WARNING: This document contains controlled technical data under the jurisdiction of the Export Administration Regulations (EAR), 15 CFR
730-774. It cannot be transferred to any foreign third party without the specific prior approval of the
U.S. Department of Commerce Bureau of Industry and Security (BIS). Violations of these regulations are punishable by fine, imprisonment, or both.
GPSG-1000
GPS/Galileo Positional Simulator
Operation Manual
PUBLISHED BY
Aeroflex
COPYRIGHT © Aeroflex 2017
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise without the prior permission of the publisher.
Original Issue
Issue 2
Issue 3
Issue 4
Issue 5
Issue 6
Issue 7
Issue 8
Issue 9
Issue 10
Issue 11
Jun 2011
Sep 2011
Nov 2011
Mar 2012
Mar 2013
Jan 2014
Feb 2015
Oct 2015
Jan 2016
Sep 2016
Nov 2017
10200 West York / Wichita, Kansas 67215 U.S.A. / (316) 522-4981 / FAX (316) 524-2623
Sub ject t o Expo rt Co nt rol, see Cov er Pag e fo r d etails.
Sub ject t o Expo rt Co nt rol, see Cov er Pag e fo r d etails.
ELECTROMAGNETIC COMPATIBILITY
Double shielded and properly terminated external interface cables must be used with this equipment when interfacing with the RS-232 and Ethernet.
For continued EMC compliance, all external cables must be shielded and 3 meters or less in length.
NOMENCLATURE STATEMENT
In this manual, GPSG-1000, Test Set or Unit refers to the GPSG-1000 GPS/Galileo Positional Simulator.
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Declaration of Conformity
The Declaration of Conformity Certificate included with the Unit should remain with the
Unit.
Aeroflex recommends the operator reproduce a copy of the Declaration of Conformity
Certificate to be stored with the Operation Manual for future reference.
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Precautions
SAFETY FIRST - TO ALL OPERATIONS PERSONNEL
GENERAL CONDITIONS OF USE
This product is designed and tested to comply with the requirements of IEC/EN61010-1 ‘Safety requirements for electrical equipment for measurement, control and laboratory use’ for Class I portable equipment and is for use in a pollution degree 2 environment. The equipment is designed to operate from installation supply Category II.
Equipment should be protected from liquids such as spills, leaks, etc. and precipitation such as rain, snow, etc. When moving the equipment from a cold to hot environment, allow the temperature of the equipment to stabilize before the equipment is connected to the supply to avoid condensation forming.
The equipment must only be operated within the environmental conditions specified in the performance data.
CASE, COVER OR PANEL REMOVAL
Opening the Case Assembly exposes the operator to electrical hazards that may result in electrical shock or equipment damage. Do not operate this Test Set with the Case Assembly open.
SAFETY IDENTIFICATION IN TECHNICAL MANUAL
This manual uses the following terms to draw attention to possible safety hazards that may exist when operating or servicing this equipment:
IDENTIFIES CONDITIONS OR ACTIVITIES THAT, IF IGNORED, CAN RESULT IN
EQUIPMENT OR PROPERTY DAMAGE, E.G., FIRE.
IDENTIFIES CONDITIONS OR ACTIVITIES THAT, IF IGNORED, CAN RESULT IN
PERSONAL INJURY OR DEATH.
SAFETY SYMBOLS IN MANUALS AND ON UNITS
CAUTION : Refer to accompanying documents. (This symbol refers to specific CAUTIONS represented on the unit and clarified in the text.)
Indicates a Toxic hazard.
Indicates item is static sensitive.
AC TERMINAL: Terminal that may supply or be supplied with AC or alternating voltage.
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SAFETY FIRST - TO ALL OPERATIONS PERSONNEL (cont)
EQUIPMENT GROUNDING PROTECTION
Improper grounding of equipment can result in electrical shock.
USE OF PROBES
Refer to Performance Specifications for the maximum voltage, current and power ratings of any connector on the Test Set before connecting a probe from a terminal device. Be sure the terminal device performs within these specifications before using the probe for measurement, to prevent electrical shock or damage to the equipment.
POWER CORDS
Power cords must not be frayed or broken, nor expose bare wiring when operating this equipment.
USE RECOMMENDED FUSES ONLY
Use only fuses specifically recommended for the equipment at the specified current and voltage ratings.
Refer to Performance Specifications for fuse requirements and specifications.
INTERNAL BATTERY
This unit contains a Lithium Ion Battery, serviceable only by a qualified technician.
EMI (ELECTROMAGNETIC INTERFERENCE)
C A U T I O N
SIGNAL GENERATORS CAN BE A SOURCE OF ELECTROMAGNETIC
INTERFERENCE (EMI) TO COMMUNICATION RECEIVERS. SOME TRANSMITTED
SIGNALS CAN CAUSE DISRUPTION AND INTERFERENCE TO COMMUNICATION
SERVICE OUT TO A DISTANCE OF SEVERAL MILES. USER OF THIS EQUIPMENT
SHOULD SCRUTINIZE ANY OPERATION THAT RESULTS IN RADIATION OF A
SIGNAL (DIRECTLY OR INDIRECTLY) AND SHOULD TAKE NECESSARY
PRECAUTIONS TO AVOID POTENTIAL COMMUNICATION INTERFERENCE
PROBLEMS.
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SAFETY FIRST - TO ALL OPERATIONS PERSONNEL (cont)
TOXIC HAZARDS
W A R N I N G
SOME OF THE COMPONENTS USED IN THIS EQUIPMENT MAY INCLUDE RESINS
AND OTHER MATERIALS WHICH GIVE OFF TOXIC FUMES IF INCINERATED.
TAKE APPROPRIATE PRECAUTIONS IN THE DISPOSAL OF THESE ITEMS.
BERYLLIA
W A R N I N G
BERYLLIA (BERYLLIUM OXIDE) IS USED IN THE CONSTRUCTION OF SOME OF
THE COMPONENTS IN THIS EQUIPMENT.
THIS MATERIAL, WHEN IN THE FORM OF FINE DUST OR VAPOR AND INHALED
INTO THE LUNGS, CAN CAUSE A RESPIRATORY DISEASE. IN ITS SOLID FORM,
AS USED HERE, IT CAN BE HANDLED SAFELY, HOWEVER, AVOID HANDLING
CONDITIONS WHICH PROMOTE DUST FORMATION BY SURFACE ABRASION.
USE CARE WHEN REMOVING AND DISPOSING OF THESE COMPONENTS. DO
NOT PUT THEM IN THE GENERAL INDUSTRIAL OR DOMESTIC WASTE OR
DISPATCH THEM BY POST. THEY SHOULD BE SEPARATELY AND SECURELY
PACKED AND CLEARLY IDENTIFIED TO SHOW THE NATURE OF THE HAZARD
AND THEN DISPOSED OF IN A SAFE MANNER BY AN AUTHORIZED TOXIC
WASTE CONTRACTOR.
BERYLLIUM COPPER
W A R N I N G
SOME MECHANICAL COMPONENTS WITHIN THIS INSTRUMENT ARE
MANUFACTURED FROM BERYLLIUM COPPER. THIS IS AN ALLOY WITH A
BERYLLIUM CONTENT OF APPROXIMATELY 5%. IT REPRESENTS NO RISK IN
NORMAL USE.
THE MATERIAL SHOULD NOT BE MACHINED, WELDED OR SUBJECTED TO ANY
PROCESS WHERE HEAT IS INVOLVED.
IT MUST BE DISPOSED OF AS “SPECIAL WASTE.”
IT MUST NOT BE DISPOSED OF BY INCINERATION.
LITHIUM
W A R N I N G
A LITHIUM BATTERY IS USED IN THIS EQUIPMENT.
LITHIUM IS A TOXIC SUBSTANCE SO THE BATTERY SHOULD IN NO
CIRCUMSTANCES BE CRUSHED, INCINERATED OR DISPOSED OF IN NORMAL
WASTE.
DO NOT SHORT CIRCUIT OR FORCE DISCHARGE SINCE THIS MIGHT CAUSE
THE BATTERY TO VENT, OVERHEAT OR EXPLODE.
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SAFETY FIRST - TO ALL OPERATIONS PERSONNEL (cont)
FIRE HAZARD
W A R N I N G
MAKE SURE THAT ONLY FUSES OF THE CORRECT RATING AND TYPE ARE
USED FOR REPLACEMENT. IF AN INTEGRALLY FUSED PLUG IS USED ON THE
SUPPLY LEAD, ENSURE THAT THE FUSE RATING IS COMMENSURATE WITH
THE CURRENT REQUIREMENTS OF THIS EQUIPMENT.
INPUT OVERLOAD
C A U T I O N
TX PORT MAXIMUM REVERSE POWER
100 mW
RX LEVEL MUST NOT EXCEED -20 dB
M
C A U T I O N
STATIC SENSITIVE COMPONENTS
CAUTION
THIS EQUIPMENT CONTAINS PARTS
SENSITIVE TO DAMAGE
BY ELECTROSTATIC DISCHARGE (ESD).
This equipment contains components sensitive to damage by Electrostatic
Discharge (ESD). All personnel performing maintenance or calibration procedures should have knowledge of accepted ESD practices and/or be ESD certified.
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Preface
SCOPE
This Manual contains instructions for operating the GPSG-1000. It is strongly recommended that the Operator become thoroughly familiar with this manual before attempting to operate the equipment.
ORGANIZATION
This manual is composed of the following chapters:
CHAPTER 1 - INTRODUCTION
Provides an introduction and a brief overview of Test Set functions and features.
CHAPTER 2 - TEST SET OPERATION
Identifies Test Set Controls, Connectors and Indicators.
Provides Power On and Power Off procedures.
Provides functional description of Graphic User Interface (GUI) components.
Provides instructions for defining Test Set parameters.
CHAPTER 3 - TEST SET FUNCTIONS
Provides functional description of Test Set functions.
CHAPTER 4 - TESTING
Provides GPS and Galileo Receiver test guidelines.
CHAPTER 5 - MAINTENANCE
Identifies Maintenance and Software Update procedures.
CHAPTER 6 - PRINCIPLES OF OPERATION
Provides information regarding Test Set principles of operation.
CHAPTER 7 - SPECIFICATIONS
Identifies Test Set specifications.
APPENDIX A - PIN-OUT TABLES
Identifies connector pin locations.
APPENDIX B - ABBREVIATIONS
Lists terms and abbreviations used in this manual.
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Service Upon Receipt of Material
UNPACKING TEST SET
Special design packing material inside this shipping container provide maximum protection for the Test Set. Avoid damaging the shipping container and packaging material when unpacking equipment; if necessary the shipping container and packaging material can be reused to ship the Test Set.
3.
4.
5.
Use the following steps to unpack the Test Set:
STEP PROCEDURE
1.
2.
6.
Cut and remove sealing tape on top of the shipping container. Open shipping container and remove top packing mold.
Grasp the Test Set firmly while restraining the shipping container. Lift the equipment and packing material vertically out of the shipping container.
Place Test Set and end cap packing on a flat, clean and dry surface.
Remove protective plastic bag from the Test Set.
Place protective plastic bag and end cap packing materials inside shipping container.
Store shipping container for possible future use.
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CHECKING UNPACKED EQUIPMENT
Inspect equipment for possible damage incurred during shipment. If Test Set has been damaged, report the damage to Aeroflex Customer Service.
Review packing slip to verify shipment is complete. Packing slip identifies the standard items as well as purchased options. Report all discrepancies to Aeroflex.
Contact:
Aeroflex
C u s t o m e r S e r v i c e D e p a r t m e n t
1 0 2 0 0 W e s t Y o r k S t r e e t
W i c h i t a , K a n s a s 6 7 2 1 5
Telephone:
8 0 0 - 8 3 5 - 2 35 0
FAX:
3 1 6 - 5 2 4 - 2 62 3 email: s e r v i c e @ a e r o f l e x . c o m
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Standard Items
ITEM
GPS/Galileo Positional Simulator
Power Supply
Power Cord (U.S.)
Power Cord (European)
Operation Manual (CD)
Getting Started Manual (paper)
Transit Case
PART NUMBER QTY
87339 1
67374 1
62302
64020
88037
1
1
1
88038 1
88493 1
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Standard Items (cont)
ITEM
Coax Cable (50ft)
GPSG Antenna Coupler
Shot Bag
RX Antenna
PART NUMBER QTY
90114 1
87636 1
88753
90113
1
1
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Optional Items
Battery Pack
ITEM
External Battery Charger
Antenna Coupler Placement Pole Kit
(Pole and D Ring)
Kit, CPLR Dual GPS
Antenna System
PART NUMBER
86196
QTY
1
87040 1
90106
1
91136 1
Kit, CPLR Triple GPS
Antenna System
91137 1
Maintenance Manual 89023 1
GPS Receiver Termination Kit,
190 Ohms
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Table of Contents
Chapter 1 - Description . . . . . . . . . . . . . . . . . . . . . . . . . 1 - 1
Chapter 2 - Test Set Operation . . . . . . . . . . . . . . . . . . . 2 - 1
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Chapter 3 - Test Set Functions . . . . . . . . . . . . . . . . . . . 3 - 1
Chapter 4 - Testing GPS/ Galileo Receivers . . . . . . . . . . 4 - 1
Measuring Time to First Fix (TTFF) and Position Accuracy . . . . . . . . . . . . . . . . . 4 - 12
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Chapter 5 - Maintenance . . . . . . . . . . . . . . . . . . . . . . . . 5 - 1
Chapter 6 - Principles of Operation . . . . . . . . . . . . . . . . 6 - 1
Principles of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 1
GPSG-1000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 1
GPS System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 2
SPS Standard Positioning Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 5
Position Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 6
GPS Timekeeping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 18
GNSS Accuracy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 19
GNSS Augmentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 20
GPS Modernization Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 24
The Galileo System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 28
Chapter 7 - Product Specifications . . . . . . . . . . . . . . . . 7 - 1
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Appendix A
Pin-Out Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A - 1
Appendix B
Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B - 1
Appendix C
Exporting, Editing and Importing Waypoints . . . . . . . . .C - 1
Appendix D
Exported and Imported File Formats . . . . . . . . . . . . . . .D - 1
Appendix E
Recording and Playing Trajectory Routes . . . . . . . . . . . E - 1
Appendix F
GPSG-1000 USB Memory Device
Format Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . F - 1
Appendix G
Connecting Dual Antenna Coupler Kit . . . . . . . . . . . . . G - 1
Appendix H
Connecting Triple Antenna Coupler Kit . . . . . . . . . . . . .H - 1
Appendix I
Direct Connecting to GPS Receivers
Requiring Antenna Load Simulators
Using the Aeroflex GPSG-1000 and Optional Kit . . . . . . I - 1
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List of Figures
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GPS System Segments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 2
GPS Satellite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 3
GPS Satellite Orbital Planes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 3
GPS SV Block Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 4
GPS SV Signal Data Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 4
GPS Monitor Stations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 5
GPS Navigation Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 6
GPS Almanac . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 7
Satellite Relative Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 8
GPS Received Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 9
GPS Received Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 9
GPS Code Correlation Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 10
GPS Nav Data Recover by Moduo 2 Addition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 10
GPS Signal After De-spreading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 11
GPS Subframe Hand-Over Word . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 12
GPS Pseudo Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 13
GPS Pseudo Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 14
Triangulation using one known point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 14
Triangulation using two known point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 15
Triangulation using three known point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 15
Triangulation using two known points in 3D space . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 15
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Triangulation using three known points in 3D space . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 16
Multipath Delays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 16
Atmospheric Delays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 17
GPS v. UTC Time Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 19
SBAS Coverage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 21
GPS Modernization Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 24
Galileo Satellite (GIOVE Test SV) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 28
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List of Tables
PS Positional Error Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 18
RAIM Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 23
Galileo Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 30
SNC, SNR and C/N0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 32
C/N0 as a Function of Noise Figure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 33
Correlation of RF Power Level and Receiver C/N0 . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 34
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Chapter 1 - Description
1.1
INTRODUCTION
1.1 .1
1.1 .2
1.2
Fig. 1-1 The Aeroflex GPSG-1000
Scope
Type of Manual: Operation Manual
Equipment Name and Model Number: GPSG-1000 GPS/Galileo Positional Simulator
Equipment Uses: Satellite constellation simulator for testing GPS and Galileo receivers.
Nomenclature Cross-Reference List
Common Name Official Nomenclature
GPSG-1000, Test Set or Unit GPSG-1000 GPS/Galileo Positional Simulator
EQUIPMENT CAPABILITIES AND FEATURES
The GPSG-1000 is a single carrier simulator, designed to be used for portable or bench testing in the GPS/Galileo Receiver testing environment. The GPSG-1000 has a twelve channel configuration with upgradable software. The simulator provides GPS legacy and modernization signals as well as Galileo signals. Simultaneous GPS and Galileo operation is provided. The GPSG-1000 simulate s static or dynamic 3D positions.
The GPSG-1000 and supplied accessories are stored in a hard plastic transit case.
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1 - 1
1.2 .1
Description
Capabilities
The GPSG-1000 provides users with the following standard capabilities:
•
•
•
•
•
•
•
•
•
•
•
Selectable single carrier
Twelve channel configuration
GPS Signals Simulated - L1, L1C, L2C, L5
Galileo Signals Simulated – E1, E5 (E5a, E5b)
Simultaneous GPS/Galileo simulation
SBAS Satellites Simulated – WAAS/EGNOS L1, L5
RF Port DC isolation for direct connect to any receiver
Antenna coupler
Large 12” touch screen with simple user interface
Remote control interface USB/LAN
Auto Almanac Load via built in GPS Receiver
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1 - 2
1.2 .2
1.2 .3
Description
Features
•
•
•
•
•
•
System Screen
SV Selection Table displays SV Geometry for RAIM testing
Programmable SV Parametrics and Health
Static or Multi-leg Dynamic Positional Simulation via Waypoint Entry System
Receiver NMEA Bus Interface
Receiver ARINC 429 Interface
Utilities
•
•
•
•
Software Upgrade
Waypoint Data Base
Operational Status
Setup
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Description
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Chapter 2 - Test Set Operation
2.1
2.2
2.2 .1
2.2 .2
INTRODUCTION
This chapter refers to local operation of a GPSG-1000 configured with factory default settings unless specified otherwise. New Test Sets are configured to start in the factory default setting. Review Installation and Power Requirements before using the Test Set.
POWER REQUIREMENTS
Power
The GPSG-1000 is powered by an internal Lithium Ion Battery. The battery charging circuit enables the operator to recharge the battery anytime the unit is connected to the
DC power supply. The GPSG-1000 can operate continuously utilizing the DC power supply. The internal battery is equipped to power the GPSG-1000 for four hours of continuous use.
AC Power Re quirements
The DC Power Supply supplied with the GPSG-1000 operates over a voltage range of 100 to 250 VAC at 47 to 63 Hz. The battery charger operates whenever DC Power (11 to 32
Vdc) is applied to the Test Set with the supplied DC Power Supply or a suitable DC power source.
NOTE: If the supply voltage is <11V, the unit will switch to internal battery. If the voltage is >32V, a 7 AMP resettable fuse on the DC input port will open, protecting the Test Set.
When charging, the battery reaches a 100% charge in approximately four hours. The
Battery Charge temperature range is >-10° to <60° C, controlled by an internal battery charger.
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2 - 1
2.2 .3
2.2 .4
Operation
Batte ry Rech arging Using GPS G-1000
STEP PROCEDURE
1.
2.
3.
4.
Connect AC Line Cable to AC PWR Connector on the AC Adaptor and an appropriate AC power source .
Connect the AC Adaptor DC output to the DC POWER Connector on the GPSG-
1000.
Verify the BATTERY indicator displays blinking green.
Allow four hours for battery charge or until the BATTERY Indicator displays a steady green.
BATTERY LED INDICATORS
Battery Voltage Low (red)
The unit turns off within one minute w/o charger.
Battery Pre-Charging (flashing yellow)
Trickle charge during extremely low voltage on the battery.
Battery Charging (flashing green)
Charge in progress.
Battery Fully Charged (green)
Battery Temperature Extreme (blue)
Temperature <0° C or >45° C can’t charge battery .
Battery Error (red)
The unit has a problem with the battery or charging system.
Battery Missing (off)
AC applied w/o battery in place.
Battery Suspended Charge (flashing red)
AC applied with battery charging suspended .
Batte ry Rech arging Using Battery Cradle
STEP PROCEDURE
1.
2.
3.
Connect AC Line Cable to AC PWR Connector on the AC Adaptor and an appropriate AC power source.
Connect the AC Adaptor DC output to the DC POWER Connector on the Battery
Cradle.
Allow four hours for battery to charge.
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2.3
2.3 .1
2.3 .2
Operation
INSTALLATION
Ventilatio n R equirements
The GPSG-1000 is convection cooled via the enclosure case. Avoid standing the instrument on or close to other equipment that is hot.
Bench Top Insta llation
The Test Set can be positioned in flat or tilted position by utilizing the built in screen
cover/stand when used in a bench top environment (Fig. 2-1).
TO AVOID DAMAGE TO TOUCH SCREEN, DO NOT STACK OTHER EQUIPMENT
ON TOP OF THE TEST SET.
Fig. 2-1 GPSG-1000 Screen Cover/Stand
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2.4
2.4 .1
Operation
CONTROLS AND CONNECTORS
Front Panel Controls
Fig. 2-2 Front Panel Controls
Control Description
Power ON/OFF The Power On/Off Button is used to power the Test Set on and off.
System LED Powered On (green)
Indicates the unit is in an operational status.
Failure (red)
Some form of failure has occurred which precludes using the display to indicate the problem (e.g. main processor failure, power supply fault, etc.).
Boot (blinking blue)
Unit is booting and is not yet able to indicate status on the display (during initial OS and application load).
Off/Standby (orange)
Unit is off, but power is supplied to the power supply from the
AC power supply.
Off w/o External Supply (off)
Unit is off, no external power supplied.
Home Button Pressing and holding the Home Button for 5 sec sets the backlight to maximum brightness.
Light Sensor Monitors the ambient light and adjusts the display brightness.
The light sensor is not operational at this time. Currently the display brightness must be set manually.
Magnetic Sensor Detects if the display cover is open or closed and used to turn off the display as part of power management.
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Operation
Control Description
Battery LED Battery Voltage Low (red)
The unit turns off within one minute without charger
Battery Pre-Charge (flashing yellow)
Trickle charge during extremely low voltage on the battery.
Battery Charging (flashing green)
Charge in progress
Battery Fully Charged (green)
Battery Temperature Extreme (blue)
Temperature <0 o
C or >45 o
C can’t charge battery
Battery Error (red)
Problem with the battery or charging system.
Battery Missing (Off)
AC applied without battery in place.
Battery Suspended Charge (flashing Red)
AC applied w/ battery charging suspended
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2 - 5
2.4 .2
Operation
Rear Panel C ontrols and Connectors
Fig. 2-3 Test Set Rear Panel Controls and Connectors
Connector
USB Host 1
USB Host 2
Description
USB standard connection that allows connection of USB devices (e.g. a USB memory stick or Network connectors).
Recommended USB memory device is Aeroflex PN 67325.
USB standard connection that allows connection of USB devices (e.g. a USB memory stick or Network connectors).
Recommended USB memory device is Aeroflex PN 67325.
USB On The Go, for future expansion.
USB OTG
GPS Rx Ant
GPS Tx Direct
GPS Tx Coupler
REF In
10MHz
REF Out
10MHz
Ethernet
Aux
External Antenna connection for Test Set internal GPS receiver.
RF output for direct connection to receiver under test. AC coupled, Maximum DC 50 V.
RF output for connection to Antenna Coupler.
The 10MHz In (5V p-p Max) Connector, is a BNC connection, used to connect the Test Set to an external frequency standard, providing a TTL signal.
The10MHz Out (1.5V p-p Nom) Connector, is a BNC connection, providing an output of the internal 10MHz reference Oscillator.
Standard Base T RJ45 connection.
This connection can be used for software upgrades and for remote operation.
26 pin D type, providing a 3.3 VDC LVTTL trigger input and 3.3
VDC LVTTL trigger output, and a 1PPS TTL L1 C/A code frame sync output. RS-232 transmitter connection provides an NMEA sentence output, the content of which corresponds to the output of the TX Direct and Coupler output ports. The NMEA sentences outputted on the RS-232 port include GGA, RMC and GSV. ARINC 429 I/O provides expansion capability for the future.
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2 - 6
2.5
2.5 .1
Operation
OPERATING PROCEDURES
Power ON Tes t Set
After completing Initial Installation, perform the following steps to Turn On the Test Set:
.
1.
2.
STEP PROCEDURE
Press On/Off Button on Front Panel to power on Test Set.
The Power Up window is displayed when the unit is first powered on or after
Factory Defaults have been restored.
2.5 .2
Fig. 2-4 Power Up Window
Power OF F Test Set
Perform the following steps to power off the Test Set:
1.
STEP PROCEDURE
Press On/Off Button on Front Panel to power down the Test Set, then press OK to confirm.
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2.6
2.6 .1
Operation
USER INTERFACE COMPONENTS
The Test Set User Interface (UI) is a touch screen control panel that provides a flexible working environment for all users. The UI uses maximized Function Windows i.e. one function window occupies the entire screen area. The Test Set User Interface (UI) is navigated locally using the Front Panel Touch Screen
Launch Bar
The Launch Bar is a vertical scrolling menu located at the left side of the User Interface.
The Launch Bar provides access to the Function Icons as shown in Fig. 2-5. The menu
must be opened to access the Function Icons. The Launch Bar is opened and closed by touching or clicking on the light gray bar at the left side the menu.
Fig. 2-5 Launch Bar - Open/Close Tab
When the Launch Bar is opened, it appears in front of any Simulation Function Windows currently occupying that area of the display. The Launch Bar can be closed to view the complete Simulation Function Window.
Fig. 2-6 Launch Bar and Simulation Function Window
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2.6 .2
2.6 .3
Operation
Launch Bar Navigation
The arrows on the top and bottom of the Launch Bar are used to scroll the Function Icons
Up and down.
Functio n K eys
The Launch Bar consists of keys that identify functions installed on the Test Set.
2.6 .4
Fig. 2-7 Function Keys
Functio n Windows
Function Windows provide visual access to the Test Set’s control parameters and displayed data.
Function How to
Opening/Closing
Function Windows
Function Windows are opened by selecting the Function Icon from the Launch Bar. Function Windows are closed by selecting the blue circle icon at the bottom of the window or by selecting the Function Icon on the Launch Bar.
Fig. 2-8 Function Window
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2.6 .5
Operation
Functio n Window Ic ons
Function Windows use the following icons to indicate various functions or states:
ICON DESCRIPTION
Closes the Function Window while leaving the function in the
Active State.
Maximizes Function Window and opens Status Bars.
Minimizes Function Window and closes Status Bars.
Selects the next tab left or right. Displays a gray background when no additional tabs are available to the left or to the right.
Displays Running and a green circle when the simulation is running.
Displays Ready and a gray circle when the simulation is stopped.
Displays remaining battery capacity in %.
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2 - 10
2.7
2.7 .1
2.7 .2
Operation
DEFINING PARAMETERS
Entering Numeric Values
Numeric values are used to define a variety of test parameters such as frequency and level. When a numeric data field is selected for editing, a group of data entry pop-up windows is launched which provides the following methods for defining the value:
Numeric Keypad and Slider Ba r
The Numeric Keypad allows the user to enter a specific numeric value. A value is entered by pressing the numbers on the keypad. The value is enabled pressing the unit of measurement on the Numeric Keypad.
Icon
Fig. 2-9 Numeric Keypad
Description
Pressing Cancel voids any entered changes and closes the group of data entry pop-up windows.
Pressing Clear resets a numeric value to 0.
Pressing Backspace deletes the last digit in the numeric value.
Pressing Next Value Selection replaces the Numeric Keypad with the Slew Data Bar. Press again and the Numeric Keypad appears.
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2 - 11
2.7 .3
Operation
Data S lew B ar
The Data Slew Bar incrementally selects specific data values by spinning the wheel.
Selecting x10 increases the step increment by a factor of 10. Selecting /10 decreases the step increment by a factor of 10.
Select UP arrow to increase data value. Select DOWN arrow to decrease data value.
Select CANCEL to void data entry.
Selecting Enter closes the Data Slew Bar.
2.7 .4
Fig. 2-10 Data Slew Bar
Drop-down Me nus
Drop-down Menus are used to list pre-defined variables. Selecting a Drop-down Menu opens the list of variables available for that field. The variable currently selected is displayed on the menu as bold white label on a blue background. Drop-down Menus can be dragged up and down on the display in order to view long lists.
2.7 .5
Fig. 2-11 Drop-down Menu
Selectable Units
Some fields may have selectable units. For those fields identified, select the units field and a drop-down menu will be displayed.
Fig. 2-12 Selectable Units
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2 - 12
2.7 .6
Operation
Locked Fields
A small padlock symbol may be displayed against certain fields indicating that the field is locked and may not be edited or accessed. The altitude field shown is locked due to the fact that a simulation is running, or the simulation mode has been set to dynamic mode. The field will become unlocked when the simulation is stopped or is in static mode.
Fig. 2-13 Locked Field
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Operation
THIS PAGE INTENTIONALLY LEFT BLANK.
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2 - 14
Chapter 3 - Test Set Functions
3.1
3.2
3.2 .1
INTRODUCTION
This chapter provides an operational description of standard simulator functions.
TEST SET FUNCTIONS
Simulation Function Window
The Simulation Function Window is used to display the selected GPS Galileo and SBAS
SV PRN’s, Visible SV’s, carrier, and PVT (position, velocity and time). The Simulation
Function Window also controls static position and altitude.
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Testing
Fig. 3-1 Simulation Function Window (GPS Static)
Fig. 3-2 Simulation Function Window (Galileo Static)
Fig. 3-3 Simulation Function Window (SBAS Static)
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Testing
Control Component
Latitude
Longitude
Altitude
RF Level
Description
Incremental Data Entry: Latitude entered in decimal format
Example: 37
Sign: N or S o
39.0000N (37 degrees, 39.0000 minutes North)
NOTE: This field is locked when SIMULATION = DYNAMIC or
TRAJECTORY.
Incremental Data Entry: Longitude entered in decimal format
Example: 97
Sign: E or W o
26.0000E (97 degrees, 26.0000 minutes East)
NOTE: This field is locked when SIMULATION = DYNAMIC or
TRAJECTORY.
Numeric Pad: Altitude: 0 to 100,000 ft in 1 ft steps or 0 to
18,288 M in 1 M steps
NOTE: This field is locked when SIMULATION = DYNAMIC or
TRAJECTORY.
Numeric Pad: RF level entered as -68 to -130 dBm in Coupler mode or -93 to -155 dBm in Direct mode.
NOTE: The listed RF Level settings are assuming 0 dBm settings for Coupler Loss, Coupler Cable and Direct Cable on the Setup I/O Window. The RF Level entry window will be reduced by the values entered for these settings.
Display Component
GPS SV PRN
GAL SV PRN
SBAS
Visible SV’s
Description
Displays selected GPS SV PRN’s. Range: 1 to 32
Displays selected Galileo SV PRN’s Range: 1 to 36
Displays SBAS SV PRN, status and System.
Example: 133:INMARSAT 4F3, AMER
Displays the total number of GPS, Galileo and SBAS SV’s available in the current simulation scenario.
Carrier
Services
Current Sim. Date
Displays selected carrier, dependent on GNSS and Carrier selections in Setup. NOTE: The GPS Services and Galileo
Services are displayed in the Services field.
GNSS System: GPS
Carrier: L1 GPS Services: C/A, Pseudo P(Y)
Carrier: L2 GPS Services: L2C, Pseudo P(Y)
Carrier: L5 GPS Services: SoL
GNSS System: Galileo
Carrier: E1 Galileo Services: I/NAV, Pseudo-G/NAV
Carrier: E5 Galileo Services: I/NAV, F/NAV
GNSS System: GPS/Galileo
Carrier: L1/E1 GPS Services: C/A, Pseudo P(Y)
Galileo Services: I/NAV, Pseudo-G/NAV
Carrier: L5/E5 GPS Services: SoL
Galileo Services: I/NAV, F/NAV
Displays GNSS service generated.
Displays Date in DD/MM/YYYY format.
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3 - 3
Testing
Display Component
Speed
Current Sim. Time
Elapsed Time
Altitude Rate
From
To
Distance To Go
Heading
Description
Displays speed in MPH or Km/h when running a dynamic or trajectory simulation, dependent on Speed setting on the
Route Edit page.
Displays Time in 24 Hr format HH/MM/SS.
NOTE: Displayed in uncorrected UTC time.
Displays elapsed time in 24 Hr format HH/MM/SS.
Displays Altitude Rate in ft/min or m/min when running a dynamic simulation, dependent on Altitude Rate setting on the
Route Edit page.
Displays name of starting waypoint when running a dynamic simulation, dependent on Name entered on the Route Edit page.
Displays name of ending waypoint when running a dynamic simulation, dependent on Name entered on the Route Edit page.
Displays the Distance To Go from the current simulated position to the ending waypoint when running a dynamic simulation.
Displays the simulated heading when running a dynamic or trajectory simulation.
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3 - 4
3.2 .2
Testing
Setup Simulation Window
The Setup Simulation Window is used to configure the test set operational parameters.
Fig. 3-4 Setup Simulation Window
Control Component
GNSS
Carrier
Simulation
Description
Drop Down Selections:
GPS - Only GPS satellites simulated.
Galileo - Only Galileo satellites simulated.
GPS+Galileo - Both GPS and Galileo satellites simulated, the number of SV’s per system is dependent on the GNSS
Allocation (dual mode) settings on the Setup Channels
Window.
Drop down menu provides selection of carrier, carrier is dependent on GNSS selection in Setup.
Drop Down Selections:
GPS - L1, L1C, L2, L2C, L5
Galileo - E1, E5, E5A
GPS + Galileo - L1/E1, L5/E5
Drop Down Selections:
Static - Single waypoint entry fixed position simulator.
Dynamic - Position simulation is dynamically changing according to parameter entries in Route and Waypoint
Windows.
Trajectory - Position simulation is dynamically changing according to data read from an NMEA sentence file loaded through the File menu screen.
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3 - 5
Testing
Control Component
SBAS
Digital Noise
Fading
PRN Signal
Description
Drop Down Selections:
AUTO - Automatic optimized selection of SBAS satellite
(WAAS/EGNOS) according to simulated position.
OFF - SBAS satellites are turned OFF.
NOTE: With AUTO selected only 5 or 11 GPS/Galileo SV’s are available. With OFF selected a full 6 or 12 GPS/Galileo SV’s are available.
NOTE: Actual Number of available SV’s is dependent on user options.
NOTE: Locations without SBAS satellite coverage will result in no SBAS signals being generated in some simulations, even though SBAS SV simulation has been enabled.
NOTE: According to the NMEA specification, the numbers 33-
64 are reserved for SBAS satellites. The offset from NMEA
SBAS SV ID to SBAS PRN is 87. For example, an SBAS PRN number of 138 minus 87 results in an SV ID of 51. From the preceding example, some receivers will report the ID of the SV as 138, while some receivers may report the ID as 51.
Drop Down Selections:
Off - When coupling to the receiver antenna.
On - When connecting directly to the receiver, bypassing the antenna/LNA.
NOTE: Automatically set to OFF when RF PORT = COUPLER.
Automatically set to ON when RF PORT = DIRECT.
NOTE: Use of digital noise via antenna coupler will result in degraded SV Signal to Noise ratio and may cause receiver to loose track or not obtain a stable fix.
Drop Down Selections:
None - SV signal amplitudes do not have fading applied.
Static - SV signal amplitudes have amplitude fading applied.
Pedestrian - SV signal amplitudes have amplitude fading applied.
Land Vehicle - SV signal amplitudes have amplitude fading applied.
Aircraft - SV signal amplitudes have amplitude fading applied.
NOTE: None, Pedestrian, Land Vehicle and Aircraft amplitude fading are recommended for use in Dynamic mode. None and
Static are recommended for use in Static mode.
NOTE: See section 3.2.2.A for additional information on
Fading and Multipath Implementation.
Drop Down Selections:
Fixed - All SV Levels are set to the amplitude selected in the
RF Level control component.
Variable - Ensures the relative SV signal levels are set proportional to the respective pseudo ranges.
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3 - 6
Testing
Control Component
Position Source
Clock
Date
Time
RF Level
RF Port
Units
Description
Drop Down Selections:
User - User entered position.
GPS - On board GPS receiver derived position.
Drop down selections:
GPSRX - simulation uses uncorrected GPS UTC time and date in conjunction with loaded almanac and ephemeris data.
USER- simulation uses User entered Time and Date which sets SV parameters against loaded almanac and ephemeris.
INTERNAL - simulation uses time and date that is available from the real time clock of the GPSG-1000.
Incremental Data Entry: Date to be used during simulation.
Incremental Data Entry: Time to be used during simulation.
NOTE: The appropriate message content announcing a future leap second event is transmitted when simulation dates are within a period starting approximately 60 days before the leap second event. The appropriate message content is updated within two hours after the leap second event.
Numeric Pad: RF level entered as -68 to -130 dBm in Coupler mode or -93 to -155 dBm in Direct mode.
NOTE: The listed RF Level settings are assuming 0 dBm settings for Coupler Loss, Coupler Cable and Direct Cable on the Setup I/O Window. The RF Level entry window will be reduced by the values entered for these settings.
Drop Down Selections:
Direct - Generator uses GPS TX DIRECT port.
Coupler - Generator uses GPS TX COUPLER port.
Drop Down Selections:
Imperial - Parameters displayed/entered in Imperial units.
SI - Parameters displayed/entered in SI units.
Aero/Imperial - Parameters displayed/entered in Imperial units, speed is display/entered in knots.
Aero/SI - Parameters displayed/entered in SI units, speed is displayed/entered in knots.
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3 - 7
Testing
Control Component
Motion Model
Lat/Long Format
Drop Down Selections:
Pedestrian
Automobile
Marine
Low Performance Aircraft
High Performance Aircraft
Custom
Unlimited
Description
The velocity and acceleration limits used during dynamic simulation mode will be based on the item chosen in the drop down selection menu. The values of the velocity and acceleration can be viewed using the Motion tab on the
Setup Motion page.
NOTE: During trajectory simulations the unlimited motion model velocity and acceleration limits are used.
Drop Down Selections:
DD.DD
o
DD o
DD o
MM.MM'
MM' SS"
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3 - 8
3.2 .2.A
Testing
Fading and Multipath Model Implementation
The GPSG-1000 firmware implements independent multipath models for each satellite channel. Each channel supports a two-state (good/bad) Rician fading model with independently configurable fading and shadowing in each state. This underlying model can also be simplified to support a Rayleigh fading model.
In Rician fading the power of the received signal varies as the dominant line-of-sight component is partially cancelled by delayed reflections of itself, particularly when the delays experienced by the reflected rays are time-varying.
In Rayleigh fading the power of the received signal varies according to the Rayleigh statistical distribution (i.e. as the radial component of the sum of two uncorrelated
Gaussian random variables). This is generally considered as a good model for scenarios where the signal has been highly scattered and there is no dominant line-of-sight component. This situation typically occurs in urban environments, and during propagation through the atmosphere.
Shadowing simulates the effect of occasionally losing the line-of-sight signal due to obstruction of the signal by nearby objects. This can occur due to the motion of the satellite across the sky taking the apparent position of satellite behind buildings of other objects, but is typically caused by motion of the user. The effect is that the multipath environment can be described as a two state system, with different behavior in the “good” or non-obstructed state and “bad” or obstructed state.
Fading is modelled as being uncorrelated between satellites and frequencies, whereas shadowing in uncorrelated between satellites, but correlated across frequencies.
There is no support for simulating multipath ray delay in the current firmware, so the model is best considered as simulating a very complex multipath environment with many multipath rays and none dominant.
The GPSG-1000 firmware models the line-of-sight component as having 0 dB power, with the power of the multipath components relative to this level.
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Testing
The multipath environments currently implemented in the GPSG-1000 are shown in the following table:
MULTIPATH
MODEL
None
Static
Pedestrian
Land
Aeronautical
DESCRIPTION
No Fading or multipath effects are simulated.
20 dB Rice factor.
0.025 Hz fading bandwidth.
No Shadowing.
Unblocked “good” state:
11.9 dB Rice factor.
40 s mean time in state.
Blocked “bad” state:
5.9 dB Rice factor.
10 s mean time in state.
5 dB attenuation.
Fading bandwidth 0.5 Hz.
Shadowing bandwidth 1 Hz.
Shadowing variation 2 dB (1 σ ).
Unblocked “good” state:
13.2 dB Rice factor.
9 s mean time in state.
Blocked “bad” state:
7.2 dB Rice factor.
1 s mean time in state.
10 dB attenuation.
Fading bandwidth 7.3 Hz.
Shadowing bandwidth 2 Hz.
Shadowing variation 2 dB (1 σ ).
20.2 dB Rice factor.
Fading bandwidth 0.01 Hz.
No Shadowing.
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3 - 10
Testing
•
•
•
•
•
The GPSG-1000 software includes pre-defined configurations for several representative multipath environments selectable in the Simulation Window’s Fading field. These environments are:
NONE - No fading or multipath effects are simulated.
STATIC - Representative of the environment for a static receiver with clear view of the sky.
PEDESTRIAN - Representative of a pedestrian in an urban environment.
LAND - Representative of a land vehicle in a rural environment.
AERONAUTIACAL - Representative of the environment experienced by a flying aircraft.
It should be noted that the real environments can change dramatically according to timeof-day satellite geometry, receiver location, and receiver motion. The pre-defined environments can therefore only be considered as representative of what might be experienced by a receiver in such an environment.
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3.2 .3
Testing
Setup Motion Window
The Setup Motion Window is used to select the motion model limits to be used in a dynamic simulation.
Fig. 3-5 Setup Motion Window
Control Component
Current Motion Model Drop down selections:
Pedestrian
Automobile
Marine
Low Performance Aircraft
High Performance Aircraft
Custom
Unlimited
Description
Maximum
Longitudinal
Acceleration
Numeric Pad: Logitudinal Acceleration entered in either feet/ second^2 with a maximum of 328.083 ft/s^2, or in meters/ second^2 with a maximum of
100 m/s^2.
Maximum
Normal
Acceleration
Maximum
Velocity
Defaults
Numeric Pad: Normal Acceleration entered in either feet/ second^2 with a maximum of 328.083 ft/s^2, or in meters/ second^2 with a maximum of
100 m/s^2.
Numeric Pad: Maximum Velocity entered in either miles per hour with a maximum of 1150.782 mph, kilometers per hour with a maximum of
1852 km/h, or knots with a maximum of 999 kts.
Returns the edited values on the Setup Motion Window to their default values.
Display Component
Maximum
Bank Angle
Description
Maximum bank angle calculated for the body in motion based on a coordinated turn. Note that a non-coordinated turn is assumed for pedestrian, automotive and marine bodies in motion, so no maximum bank angle is displayed.
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3.2 .4
Testing
Setup Channels Window
The Setup Channels Window is used to configure the total SV’s available in a simulation and in a dual mode simulation to allocate the number of SV’s used for GPS, Galileo and
SBAS.
Fig. 3-6 Setup Channels Window
Control Component
GNSS SVs
GPS SV’s
Galileo SV’s
SBAS SV’s
Default
Description
Numeric Pad: Sets the total number of GNSS system SV's.
The total number of GNSS and SBAS SVs cannot exceed 6 on a 6 channel unit, or 12 on a 12 channel unit.
Numeric Pad: Sets the total number of GPS SV’s available for simulation. Range 1 - 6 (6 Ch) or 1 - 12 (12 Ch) SV’s. Total
GPS, Galileo and SBAS SV’s can not exceed 6 (6 Ch) or 12
(12 Ch) SV’s. Only used during GPS+Galileo dual mode simulation.
Numeric Pad: Sets the total number of Galileo SV’s available for simulation. Range 1 - 6 (6 Ch) or 1 - 12 (12 Ch) SV’s. Total
GPS, Galileo and SBAS SV’s can not exceed 6 (6 Ch) or 12
(12 Ch) SV’s. Only used during GPS+Galileo dual mode simulation.
Numeric Pad: Sets the total number of SBAS SV’s available for simulation. Range 0 - 4 SV’s. Total GPS, Galileo and SBAS
SV’s can not exceed 6 (6 Ch) or 12 (12 Ch) SV’s. Only used during GPS+Galileo dual mode simulation.
Sets the allocated SV’s to default values of GPS SV’s = 3 (6
Ch) or 6 (12 Ch), Galileo SV’s = 3 (6 Ch) or 6 (12 Ch) and
SBAS SV’s = 0.
Display Component
Available Channels
Description
Displays the total number of available channels. 6 channels for standard unit or 12 channels if option 1 is installed.
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3 - 13
3.2 .5
Testing
Setup I/O Window
The Setup I/O Window is used to configure the test set Loss and Input/Output operational parameters.
Fig. 3-7 Setup I/O Window
Control Component
Coupler Loss
Coupler Cable
Direct Cable
Ext Ref Out
Reference Source
Trigger
Description
Numeric Pad: Antenna Coupler insertion loss in dB. Range: 0 to 40 dB
Numeric Pad: Antenna Coupler RF coax cable loss in dB.
Range: 0 to 12 dB.
NOTE: If using either the Dual, or Triple GPS Antenna Coupler
Kits please see the instructions for the appropriate kit in either
Appendix G or H to determine the loss value to enter in this control component.
Numeric Pad: Direct RF coax cable loss in dB. Range: 0 to 12 dB.
NOTE: If using the optional GPS Receiver Termination Kit see the instructions for entering the appropriate direct cable loss value for the components in Appendix I.
Drop Down Selections:
ON - External reference output ON.
OFF - External reference output OFF.
Drop Down Selections:
INT - Internal 10 MHz TCXO.
EXT - External 10 MHz input.
Drop Down Selections:
Auto - Simulation will run immediately after the run button is pressed.
External - Simulation will run once the external trigger line toggles from a 3.3 LVTTL low level to a high level.
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3.2 .6
Testing
SV PRN Selection Function Window
The SV PRN Selection Function Window allows the user to select specific GPS/Galileo
SV’s for editing. The available SV’s, according to the currently loaded almanac and UTC, are displayed in two tables. One table for GPS SV’s and one table for Galileo SV’s. The tables display the SV PRN number, satellite geometry and health. The satellites selected determine the accuracy of the positional simulation. SV’s which are currently being use are displayed in green text and SV’s which are available for use, but not currently being used are displayed in white text.
Fig. 3-8 SV PRN Selection Function Window
Display Component
Select
SV
Elevation
Azimuth
Health
Reset
Description
Displays SV status On or Off.
Displays SV number. Range GPS: 1 to 32, GAL: 1 to 36.
Displays SV Elevation in degrees. Range: 0 to 90 deg.
Displays SV Azimuth in degrees. Range 0 to +/-180 deg.
Displays SV Health GOOD or BAD.
Returns items edited on the SV PRN Edit Window to their default values.
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3 - 15
3.2 .7
Testing
SV PRN E dit Window
The SV PRN Edit Window opens when an SV line is selected in either the GPS or GAL tables, displayed in the SV PRN Selection Function Window. The SV PRN Edit Window allows the user to set parameters specific to the SV such as Doppler Step, Pseudo Range
Step Error, Carrier Coherence, Satellite Health and Amplitude offset.
Fig. 3-9 SV PRN Edit Window
Control Component
Select
Doppler Error
Amp. Offset
Duration
Step Error
Code/Carrier
Coherence
Satellite Health
Description
Drop down selections:
On - Turns SV on
Off - Turns SV off
Replace - Opens SV select window. To replace current SV, highlight desired SV and press Apply.
Numeric Pad: Sets SV Doppler shift +/- 5KHz in 1Hz increments.
NOTE: Doppler shift for each SV is applied dynamically throughout the simulation run time. This parameter introduces a step change in Doppler (used for RAIM testing).
Numeric Pad: Sets SV carrier amplitude offset from nominal
+15dB to -15dB in .1dB increments. NOTE: If PRN Signal is set to Variable - SV amplitudes are set according to SV geometry and RF Level setting. If set to Fixed - equal SV amplitudes are set.
Numeric Pad: Sets the duration in time for which the Doppler error will be applied to the SV signal output.
Numeric Pad: Sets SV pseudo range error +/- 1000m in .001 m increments or +/- 3280.839 ft in .001 ft increments.
Numeric Pad: Sets frequency variation between SV code carriers 2m/S range in 1mm/S increments or 6.561 ft/S range in .001 ft/S increments.
Drop down: Allows selection of GOOD or BAD. (Carried in GPS
Nav Data)
NOTE: Not displayed for Galileo SV’s
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Testing
Control Component
GAL Integrity
Cancel
Apply
Description
Allows selection of CONNECTED or DISCONNECTED (Carried in Galileo Nav Data). Only displayed in Galileo SV’s.
NOTE: Not displayed for GPS SV’s
Cancel parameter change, reverts to previous setting
Applies parameter change
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3 - 17
3.2 .8
Testing
Route Function Wind ow
The Route Function Window is used to organize and configure the waypoints used in a dynamic simulation. Up to 9,999 waypoints may be used in a dynamic simulation. The
Route Function Window is also used to load saved routes, manage routes and validate routes.
Fig. 3-10 Route Function Window
Control Component
Load
Manage
Validate Route
Description
Opens Find Route Window to load a saved route. Highlight the saved route and press Open. The route name will be displayed in the Route window.
Opens Manage Routes Window to save, rename or delete a route. Highlight route and press Delete to delete a route.
Press Save to save the current route. Highlight route and then press on the File Name Window to rename a route.
Validates the current route to let the user know if there are any route errors. When Validate Route is pressed the route is checked and if no errors are found no error message is displayed, however if any errors are detected an “Error(s) found in route” message is displayed along with a description of the error.
Loop On Loop OFF Loop ON will force the body in motion to travel from the last route point to the first route point which will effectively create an endless loop along the route. Loop OFF will stop the body in motion once it has reached the last route point in the route.
Clear All When selected this will clear all of the information from the current route enabling the user to enter a new series of route points without having to perform a number of deletes.
description of Loop and Clear buttons
Add
Delete
Edit
Opens Stored Waypoints Window. To add a waypoint to the route, highlight the route and press Next to display the Route
Edit Window.
Deletes the selected waypoint from the route.
Opens the Route Edit Window to edit the selected waypoint.
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Testing
Control Component
Move Up
Move Down
Description
Moves the highlighted waypoint up in the list of waypoints.
Moves the highlighted waypoint down in the list of waypoints.
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3.2.9
Testing
Route Edit Stored Window
The Route Edit Stored Window is used to display all stored waypoints.
Fig. 3-11 Route Edit Stored Window
Control Component
Sorted By
Cancel
Next
Description
Drop down selections: Code, Name, City, Country, Latitude,
Longitude and Altitude.
Closes the Route Edit Stored Window and returns to the Route
Window.
Opens the Route Edit Window for configuration of the highlighted waypoint.
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3.2.10
Testing
Route Edit Edit Window
The Route Edit Edit Window is used to configure individual waypoints, including the
Altitude Rate, Speed, Acceleration and Turn Radius used during dynamic simulations.
Fig. 3-12 Route Edit Edit Window
Control Component
Name
Latitude
Longitude
Altitude
Turn Radius
Acceleration
Speed
Altitude Rate
Description
Alpha Numeric Pad: Allows editing of selected waypoint name.
Numeric Pad: Latitude entered in decimal format
Example: 37
Sign: N or S.
o
39.0000N (37 degrees, 39.0000 minutes North)
Numeric Pad: Longitude entered in decimal format
Example: 97 o
Sign: E or W.
26.0000E (97 degrees, 26.0000 minutes East)
Numeric Pad: Altitude: 0 to 100,000 ft in 1 ft steps or 0 to
18,288 M in 1 M steps.
Numeric Pad: Turn Radius: 3.281 to 328,084 ft in .001 ft steps or 1 to 100,000 m in .001 m steps.
NOTE: To calculate the minimum turning radius of the body in motion, the following calculation can be performed using the individual speed and acceleration of each route point.
Speed (squared) m/s
Turn Radius = ----------------------------
Acceleration m/s/s
NOTE: The separation between waypoints should be greater than four times the turning radius between the waypoints.
Numeric Pad: Acceleration: +/-328.084 ft/s^2 in .001 ft/s^2 steps or +/- 100 m/s^2 in .001 m/s^2 steps.
Numeric Pad: Speed: 0 to 1150.000 Mph in .001 Mph steps or
0 to 1850.745 Km/h in .001 Km/h steps.
Numeric Pad: Altitude Rate: +/-5,905 ft/min in .001 ft/min steps or +/-1800 m/min in .001 m/min steps.
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Testing
Control Component
Cancel
Done
Description
Closes the Route Edit Edit Window and returns to the Route
Window.
Closes the Route Edit Edit Window and returns to the Route
Window.
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3.2 .11
Testing
Waypoint Function Window
The Waypoint Function Window is used to configure the waypoints that comprise a 3D
Navigation simulation.
Fig. 3-13 Waypoint Function Window
Control Component
Sorted By
Add
Delete
Edit
Use
Defaults
Description
Drop down selections: Code, ICAO Code, Name, City, Country,
Latitude, Longitude, Altitude.
Opens Waypoint Edit Window, so that a new waypoint may be created.
Deletes selected waypoint.
NOTE: Allow approximately 15 seconds for the selected waypoint to be deleted after pressing Delete.
NOTE: Permanent waypoints can’t be deleted.
Opens Waypoint Edit Window for editing of selected waypoint.
Opens the Simulation Window and loads the Latitude,
Longitude and Altitude from the selected waypoint. Used in a
Static simulation only.
NOTE: This field is locked when SIMULATION = DYNAMIC.
Deletes all user entered waypoints from GPSG-1000.
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Testing
Display Component
Code
Name
City
Country
Latitude
Longitude
Altitude
Displays Waypoint Code.
Displays Waypoint Name.
Description
Displays Waypoint City.
Displays Waypoint Country.
Displays Waypoint Latitude in decimal format. Example:
37
S.
o
39.0000N (37 degrees, 39.0000 minutes North) Sign: N or
Displays Waypoint Longitude in decimal format. Example:
97
W.
o
26.0000E (97 degrees, 26.0000 minutes East) Sign: E or
Displays Altitude 0 to 100,000 ft in 1 ft steps.
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3.2 .12
Testing
Waypoint Edit Stored Window
The Waypoint Edit Stored Window is used to display the Current Stored Waypoints.
Waypoints can be selected from a table, to be edited on the Waypoint Edit Edit Window.
Fig. 3-14 Waypoint Edit Window
Control Component
Sorted by
Cancel
Next
Description
Drop down selections: Code, Name, City, Country, Latitude,
Longitude and Altitude.
Cancels Waypoint edits, closes Waypoint Edit Window and reverts to Waypoint Window.
Opens Waypoint Edit Edit Window.
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3.2 .13
Testing
Waypoint Edit Edit Window
The Waypoint Edit Edit Window is used to make changes to a selected waypoint or create a new waypoint. Waypoints may be selected from a table on the Waypoint Window or
Waypoint Edit Stored Window. Permanent waypoints can’t be edited.
Fig. 3-15 Waypoint Edit Edit Window
Control Component
Code
ICAO Code
Name
City
Country
Latitude
Longitude
Altitude
Cancel
Done
Description
Alpha Numeric Pad: Enter or change waypoint Code.
Alpha Numeric Pad: Enter or change waypoint ICAO Code.
Alpha Numeric Pad: Enter or change waypoint Name.
Alpha Numeric Pad: Enter or change waypoint City.
Alpha Numeric Pad: Enter or change waypoint Country.
Incremental Data Entry: Enter or change waypoint Latitude in decimal format. Example: 37 minutes North) Sign: N or S.
o
39.0000N (37 degrees, 39.0000
Incremental Data Entry: Enter or change waypoint Longitude in decimal format. Example: 97 minutes East) Sign: E or W.
o
26.0000E (97 degrees, 26.0000
Numeric Pad: Enter or change waypoint Altitude 0 to 100,000 ft in 1 ft steps.
Cancels Waypoint edits, closes Waypoint Edit Window and opens Waypoint Window.
Closes Waypoint Edit Window and opens Waypoint Window, saving the edited waypoint into the Waypoint List.
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3.2 .14
Testing
GPS R X F unction Window
The Internal GPS Receiver may be used to obtain a current Almanac, location and UTC for use in simulations. This removes the requirement for a periodic manual yuma text format almanac (*.alm), download from the U.S. Coast Guard website and subsequent upload to the GPSG-1000 memory.
When testing a GPS receiver, if the simulated position is too far from the last acquired position or the simulated time and date are to far from the last acquired time and date the receiver will initiate a warm start which, dependant on receiver type, will take longer than a hot start to acquire a position fix. As the last location would likely be the current position, the latitude and longitude from the internal GPS receiver may be used by the simulation, which would then allow the receiver under test to hot start.
Fig. 3-16 GPS Receiver Window
Control Component
GPS Receiver
Load Almanac from
GPS Rx
Loads almanac from internal GPS receiver. Download status is displayed in the Almanac Status display window.
GPS Receiver Reset Initiates a Cold Boot of the internal GPS receiver.
Record Trajectory
Description
Selects internal GPS receiver.
When activated this control begins recording trajectory data produced by the internal receiver. The recording will continue until the Stop Recording button is pressed. The data will be stored in a file with the following naming convention
MMDDYYYY_HHMMSS.nme when the stop recording button is pressed.
NOTE: The Record Trajectory function should only be initiated once a 3D fix has been achieved by the receiver.
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3 - 27
Testing
Display Component
Current Data/Time
Position Fix
Latitude
Longitude
Altitude
Speed
Almanac Status
Active Satellite
SNR
Description
Displays the current date and UTC time received by the internal GPS Receiver.
Indicates No Position Fix, 2D Solution or 3D Solution
Waypoint Latitude in decimal format.
Example: 37
Sign: N or S.
o
39.0000N (37 degrees, 39.0000 minutes North)
Waypoint Longitude in decimal format.
Example: 97 o
Sign: E or W.
26.0000E (97 degrees, 26.0000 minutes East)
Displays Altitude as determined by the internal GPS receiver.
Displays Speed as determined by the internal GPS receiver.
Indicates current week and status of the Almanac being received by the internal GPS receiver.
Displays SV’s in view.
GPS Receiver SNR figure.
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3.2 .15
Testing
Maintenance Functio n Window
Selecting the Maintenance icon from the Launch Bar Menu will display the Maintenance sub-menu. The Maintenance sub-menu contains the Calibration and Diagnostics icons.
Fig. 3-17 Maintenance Menu
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3 - 29
3.2 .16
Testing
Calibration Function Window
Selecting Calibration from the Maintenance sub-menu will display the Calibration
Password Entry Window. The Calibration Function Window is password protected.
Contact Aeroflex for the default password. Enter the password to open the Calibration
Function Window. See Chapter 5 - Maintenance for details.
Fig. 3-18 Calibration Password Window
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3 - 30
3.2 .17
Testing
Diagnostics Function Window
Selecting Diagnostics from the Maintenance sub-menu will display the Diagnostics
Function Window. See Chapter 5 - Maintenance for details.
Fig. 3-19 Diagnostics Function Window
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3 - 31
3.2 .18
Testing
File Almana cs Fu nction Window
The File Almanacs Function Window is used to manage the Almanac files stored in the
GPSG-1000 and to manage the Almanac file used during the simulation.
Fig. 3-20 File Almanacs Function Window
Control Component
Load Almanac
Manage Almanacs
GPS Rx
Default
Clear Almanacs
Import from USB
Export to USB
Description
Opens the Load Almanac Window. Select Almanac file and press Open to load Almanac file for use in simulation.
Selected file name will be displayed in the Current Almanac
File Window.
Opens the Manage Almanacs Window. Press Save to save the
Current Almanac File to the Almanac file list. To delete a saved Almanac file, select Almanac file from list and press
Delete.
Opens the GPS Rx page and begins an almanac download from the GPS constellation.
Loads the default system almanac for use.
The default almanac is from GPS week 574, dated Aug. 22, 2010.
Deletes ALL user created almanac files stored in the unit.
Copies almanac files from a USB drive to the internal storage area of GPSG-1000.
Copies all almanac files from the internal storage area of
GPSG-1000 to a USB drive.
Display Component Description
Current Almanac File Displays the file name of the Almanac file currently used for simulations.
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3.2 .19
Testing
File Routes Functio n Win dow
The File Routes Function Window is used to manage the Route files stored in the GPSG-
1000 and to manage the Route file used during a dynamic simulation.
Fig. 3-21 File Routes Function Window
Control Component
Load Route
Manage Routes
Load Default
Clear Routes
Import from USB
Export to USB
Description
Opens the Load Route Window. Select Route file and press
Open to load Route file for use in dynamic simulation.
Selected file name will be displayed in the Current Route File
Window.
Opens the Manage Routes Window. Press Save to save the
Current Route File to the Route file list. To delete a saved
Route file, select Route file from list and press Delete.
Loads the default route file.
Deletes ALL route files stored in the unit.
Copies route files from a USB drive to the internal storage area of GPSG-1000.
Copies all route files from the internal storage area of
GPSG-1000 to a USB drive.
Display Component
Current Route File
Description
Displays the file name of the Route file currently used for dynamic simulations.
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3.2 .20
Testing
File Settings Function Window
The File Settings Function Window is used to manage the Settings files stored in the
GPSG-1000 and to manage the Current Settings File.
Fig. 3-22 File Settings Function Window
Control Component
Load Settings
Manage Settings
Load Default
Clear Settings
Import from USB
Export to USB
Description
Opens the Load Settings Window. Select Settings file and press Open to load Settings file for setup of the unit. Selected file name will be displayed in the Current Settings File
Window.
Opens the Manage Settings Window. Press Save to save the
Current Settings File to the Settings file list. To delete a saved
Settings file, select Settings file from list and press Delete.
Loads factory default settings.
Deletes ALL settings files stored in the unit.
Copies settings files from a USB drive to the internal storage area of GPSG-1000.
Copies all settings files from the internal storage area of
GPSG-1000 to a USB drive.
Display Component Description
Current Settings File Displays the file name of the settings file currently used to setup the unit.
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3 - 34
3.2 .21
Testing
File Trajec tory Functio n Win dow
The File Trajectory Function Window is used to manage the trajectory files stored in the
GPSG-1000 and to load the trajectory file used during a trajectory mode simulation.
Fig. 3-23 File Trajectory Function Window
Control Component
Load Trajectory
Manage Trajectory
Clear Trajectory
Default Trajectory
Import from USB
Export to USB
Description
Loads the Trajectory Window. Select trajectory file and press
Open to load trajectory file for use in trajectory simulation.
Selected file name will be displayed in the Current Trajectory
File Window.
Opens the Manage Trajectory Window. Press Save to save the
Current Trajectory File to the trajectory file list. To delete a saved trajectory file, select NMEA file from list and press
Delete.
Deletes ALL trajectory files stored in the unit.
Loads the default system trajectory file for trajectory mode simulation playback.
Copies trajectory files from a USB drive to the internal storage area of GPSG-1000.
Copies all trajectory files from the internal storage area of
GPSG-1000 to a USB drive.
Display Component
Current Trajectory
File
Description
Displays the file name of the trajectory file currently used for trajectory simulation.
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3 - 35
3.2 .22
Testing
Kml Function Window
The Kml Function Window is used to manage the Kml files stored in the GPSG-1000 and to manage the Kml file used during a trajectory simulation.
Fig. 3-24 Kml Window
Control Component
Load Traj
Load Route
Clear Settings
Import from USB
Export to USB
Description
Opens the Load Kml Windows. Select a Kml file and press
Open to load the Kml file. Selected file name will be displayed in the Kml File Window. During the load process the latitude, longitude and absolute altitude data from the Kml file, along with the Maximum Velocity, Conversion Sampling Rate, and
Minimum Turning Radius from control components of the Kml
Window will be used to create a trajectory file 2stored in GDT format on the unit. The data loaded onto the unit during the conversion of the Kml file can be played as a trajectory simulation.
Opens the Load Kml WIndow. Select a Kml file and press
Open. The latitude, longitude and absolute altitude data from the Kml file will be inserted onto the Route page along with the
Maximum Velocity and Minimum Turning Radius from the Kml
Window, and the Acceleration from the selected motion model.
The data loaded onto the Route page can then be played as a dynamic simulation, although further manual editing of the route data may be necessary for proper playback.
Deletes ALL Kml files stored in the unit.
Copies Kml files from a USB drive to the internal storage area of GPSG-1000.
Copies all Kml files from the internal storage area of
GPSG-1000 to a USB drive.
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3 - 36
Testing
Display Component Description
Current Settings File Displays the file name of the Kml file currently used to setup the unit.
Maximum Velocity 0 to 1118 Mph or 0 to 1800 Km/h
Conversion Sampling
Rate
1, 2, 4, or 5 Hz
Minimum Turning
Radius
0 to 328081 ft or 0 to 99999 m
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3 - 37
3.2 .23
Testing
Way point Window
The Waypoint Window is used to manage the user entered waypoints stored in the GPSG-1000.
Fig. 3-25 Waypoint Window
Control Component
Clear Settings
Import from USB
Export to USB
Description
Deletes all user entered waypoints stored in the unit.
Copies user entered waypoints from a USB drive to the internal storage area of GPSG-1000.
Copies all user entered waypoints from the internal storage area of GPSG-1000 to a USB drive.
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3 - 38
3.2 .24
Testing
System Function Window
Selecting the System icon from the Launch Bar Menu will display the System sub-menu.
The System sub-menu contains the Options, System Configuration and System Update icons. See Chapter 5 - Maintenance for details.
Fig. 3-26 System Menu
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Testing
THIS PAGE INTENTIONALLY LEFT BLANK.
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3 - 40
Chapter 4 - Testing GPS/ Galileo Receivers
4.1
4.1 .1
INTRODUCTION
This chapter provides details of standard tests for GPS receivers.
Antenna Coup ler Installation
Perform the following steps to Install the Antenna Coupler
1.
2.
3.
4.
5.
STEP PROCEDURE
Ensure the GPSG-1000 is within 50 ft of the aircraft under test GPS antenna (top fuselage).
Place the Shot Bag weight over the center section of the GPS Antenna Coupler.
Connect the 50 ft RF Coax Cable to the GPSG-1000 Coupler TX TNC connector.
Perform Setup procedure 4.1.3
Place the Antenna Coupler over the GPS antenna on the top side of the aircraft frame.
NOTE: In a dual or triple GPS system installations, additional Antenna Couplers may be used via a power splitter.
Fig. 4-1 GPSG-1000 RF Connection
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4 -1
4.1 .2
Testing
Setup Basic Static Simulation
Perform the following steps for Setup.
1.
2.
3.
4.
5.
STEP PROCEDURE
Press Power On/Off Key for a minimum of one second to power up test set.
Select Launch Bar tab to display launch bar.
Select Setup function key to display Setup Window.
Select Simulation tab.
Confirm the following settings and change as necessary.
GNSS:
GNSS = GPS
Carrier = L1
SBAS = Off
Simulation = Static
Digital Noise = OFF – when coupling to the receiver antenna. ON – when connecting directly to the receiver, bypassing the antenna/LNA.
NOTE: Use of digital noise via receiver antenna, will result in degraded SV
Signal to Noise ratio and may cause receiver to loose track or not obtain
a stable fix.
Fading = None
PRN Signal = Fixed
Position Source = User
6.
Simulation Start Time:
Clock = User
Date = For optional entry of date
Time = For optional entry of time
RF Output:
RF Level = When setting the output level of GPS generated signal, a setting of
-115 to -120 dB should be adequate for most receivers. When directly connecting to a receiver, the nominal gain of the antenna should be taken into consideration and the output level of the GPSG-1000 adjusted accordingly.
RF Port = COUPLER (if using antenna coupler) or DIRECT (direct connect to GPS
UUT).
Units = Imperial
Select Almanac tab on the File page and press Load Default.
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4 -2
Testing
7.
STEP
Select I/O tab.
8.
9.
PROCEDURE
Loss:
Coupler Loss = Figure in dB marked on Antenna Coupler.
Coupler Cable = Figure in dB marked on RF Coax Cable.
Direct Cable = Figure in dB marked on RF Coax Cable.
Input/Output:
Ext Ref Out = OFF
Reference Source - INT
Trigger = Auto
Select Simulation Function Key from the Launch Bar.
Perform the following steps to complete Simulation:
PVT:
Latitude = For Optional entry of test Latitude
Longitude = For Optional entry of test Longitude
Altitude = For Optional entry of test Altitude
10.
11.
Select RUN key to start simulation.
Select STOP key to discontinue simulation.
NOTE : Most GPS receivers expect ACTIVE antennas, this means they supply a DC
voltage to the antenna connector. The GPSG-1000 has built in DC voltage
blocking on the GPSG TX Port.
GPS TX PORT: APPLIED DC SHOULD NOT EXCEED +50 V
NOTE : Some receivers “sense” current draw on the DC supply to their active antenna.
If there is no current drawn, they may assume that no antenna is connected.
In such cases, the current draw must be simulated by some resistive load and
perhaps a series inductor between the signal line and the ground. Such a device
may need to be custom built, depending on the receiver requirements.
NOTE : It is recommended that the receiver under test is “cold started” and a fresh almanac obtained from the GPSG-1000 simulation. This process may take several minutes, dependent on specific receiver.
NOTE: Some receivers will not obtain a stable fix when using a simulation time earlier than the selected almanac. Generally it is best to utilize an almanac that is dated at least one day before the simulation date.
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4 -3
4.1 .3
Testing
Setup Basic Dynamic Simulation
Perform the following steps for Setup:
1.
2.
3.
4.
5.
STEP PROCEDURE
Press Power On/Off key for a minimum of one second to power up test set.
Select Launch Bar tab to display launch bar.
Select Setup function key to display Setup Window.
Select Simulation tab.
Confirm the following settings and change as necessary:
GNSS:
GNSS = GPS
Carrier = L1
SBAS = Off
Simulation = Dynamic
Digital Noise = OFF when coupling to the receiver antenna. ON when connecting directly to the receiver, bypassing the antenna/LNA.
NOTE: Use of digital noise via receiver antenna, will result in degraded SV
Signal to Noise ratio and may cause receiver to loose track or not obtain
a stable fix.
Fading = None
PRN Signal = Fixed
Position Source = User
6.
Simulation Start Time:
Clock = User
Date = For optional entry of date
Time = For optional entry of time
RF Output:
RF Level = When setting the output level of GPS generated signal, a setting of
-115 to -120 dB should be adequate for most receivers. When directly connecting to a receiver, the nominal gain of the antenna should be taken into consideration and the output level of the GPSG-1000 adjusted accordingly.
RF Port = COUPLER (if using antenna coupler) or DIRECT (direct connect to GPS
UUT)
Units = Imperial
Select Almanac tab on the File page and press Load Default.
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4 -4
Testing
8.
9.
10.
11.
12.
13.
14.
7.
STEP
Select I/O tab.
PROCEDURE
Loss:
Coupler Loss = Figure in dB marked on Antenna Coupler
Coupler Cable = Figure in dB marked on RF Coax Cable
Direct Cable = Figure in dB marked on RF Coax Cable
Input/Output:
Ext Ref Out = OFF
Reference Source = INT
Trigger = Auto
15.
16.
17.
To enter a route, select Route function key from the Launch Bar.
Select Route Points Add button.
Select a waypoint from the Stored Waypoints table.
Select the Next button.
Enter the desired information on the Route Point edit page and press the Done button.
Complete entering all the Route points.
To save Route for future use select Route function key from the Launch Bar.
Select Route Manage button, then enter file name on the Manage Routes popup and press Save .
Select Simulation tab.
Select RUN key to start simulation.
Select STOP key to stop simulation.
NOTE: Most GPS receivers expect active antennas. This means they supply a DC
voltage to the antenna connector. The GPSG-1000 has built in DC
voltage blocking on the GPSG TX Port.
NOTE: Some receivers ‘sense’ current draw on the DC supply to their active
antenna. If there is no current drawn, they may assume that no antenna
is connected. In such cases, the current draw must be simulated by some
resistive load and perhaps a series inductor between the signal line and
the ground. Such a device may need to be custom built, depending on the
receiver requirements.
NOTE: It is recommended that the receiver under test is ‘cold started’ and a fresh
almanac obtained from the GPSG-1000 simulation. This process may
take several minutes, dependent on the specific receiver.
NOTE: Some receivers will not obtain a stable fix when using a simulation time
earlier than the selected almanac. Generally it is best to utilize an
almanac that is dated at least one day before the simulation date.
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4 -5
4.1 .4
Testing
Setup Basic Trajectory Simulation
Perform the following steps for Setup:
1.
2.
3.
4.
5.
STEP PROCEDURE
Press Power On/Off Key for a minimum of one second to power up test set.
Select Launch Bar tab to display launch bar.
Select Setup function key to display Setup Window.
Select Simulation tab.
Confirm the following settings and change as necessary:
GNSS:
GNSS = GPS
Carrier = L1
SBAS = Off
Simulation = Trajectory
Digital Noise = OFF – when coupling to the receiver antenna. ON – when connecting directly to the receiver, bypassing the antenna/LNA.
NOTE: Use of digital noise via receiver antenna will result in degraded SV Signal
to Noise ratio and may cause receiver to loose track or not obtain a stable
fix.
Fading = None
PRN Signal = Fixed
Position Source = User
6.
Simulation Start Time:
Clock = User
Date = For optional entry of date
Time = For optional entry of time
RF Output:
RF Level = When setting the output level of GPS generated signal, a setting of
-115 to -120 dB should be adequate for most receivers. When directly connecting to a receiver, the nominal gain of the antenna should be taken into consideration and the output level of the GPSG-1000 adjusted accordingly.
RF Port = COUPLER (if using antenna coupler) or DIRECT (direct connect to
GPS UUT)
Units = Imperial
Select Almanac tab on the File page and press Load Default.
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4 -6
Testing
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
7.
STEP
Select I/O tab.
PROCEDURE
Loss:
Coupler Loss = Figure in dB marked on Antenna Coupler
Coupler Cable = Figure in dB marked on RF Coax Cable
Direct Cable = Figure in dB marked on RF Coax Cable
Input/Output:
Ext Ref Out = OFF
Reference Source = INT
Trigger = Auto
Select GPS RX function key from the Launch Bar.
Ensure that the GPS receiver antenna is correctly connected to the GPSG-1000 and that the test set has an unobstructed view of the sky.
To start the recording process press Record Trajectory button.
Press Stop Recording button to stop the recording process.
To load a data file for playback, select File function key from the Launch Bar.
Select the Trajectory tab and press the Load button.
On the Load Trajectory popup, select the desired file from the list and press the
Load button.
Select Simulation function key from the Launch Bar.
Select RUN key to start simulation.
Select STOP key to stop simulation.
NOTE: When a field containing NMEA sentences is imported to the GPSG-1000
for playback, at a minimum the file must contain sentence GGA or RMC.
If the file contains only GGA messages the GPSG-1000 will use the date
specified on the Setup page of the unit. If sentence RMC is available in
the imported file, then the date of the simulation will match that of the
data within the file. In either of the previous two cases, the correctly
dated almanac file must be loaded to match the date of the simulation if
the user intends to match the SV constellation simulated by the GPSG-
1000 to that of the SV constellation in view by the receiver at the time of
the recording.
NOTE: Most GPS receivers expect active antennas. This means they supply a DC
voltage to the antenna connector. The GPSG-1000 has built in DC
voltage blocking on the GPSG TX Port.
NOTE: Some receivers ‘sense’ current draw on the DC supply to their active
antenna. If there is no current drawn, they may assume that no antenna
is connected. In such cases, the current draw must be simulated by some
resistive load and perhaps a series inductor between the signal line and
the ground. Such a device may need to be custom built, depending on the
receiver requirements.
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4 -7
Testing
STEP PROCEDURE
NOTE: It is recommended that the receiver under test is ‘cold started’ and a fresh
almanac obtained from the GPSG-1000 simulation. This process may
take several minutes, dependent on the specific receiver.
NOTE: Some receivers will not obtain a stable fix when using a simulation time
earlier than the selected almanac. Generally it is best to utilize an
almanac that is dated at least one day before the simulation date.
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4 -8
4.1 .5
4.1 .6
Testing
GPS R eceive r Commu nication
Some receivers may have maintenance pages the user can access to view SV parameters and positional information. Access may either be directly via a display/control or by the use of proprietary software.
For a standardized means of accessing all receiver data most receivers support the
NMEA-183 protocol. NMEA -183 compliant receivers send data continuously through either a serial or USB interface, in the form of text sentences, which may be monitored by
PC using a suitable application. The NMEA-183 protocol supports six basic sentences, and each provides a different data type. Refer to table 4-1. The first word in each sentence is the three letter data type.
Data Type
GGA
GLL
Description
Fix information
Latitude and longitude information
GSA
GSV
Overall satellite data
Detailed data for satellites in view
RMC Recommended minimum data for
GPS
VTG Vector track and speed over ground
Table 4-1 Basic NMEA-183 Sentences
The information from the GSA sentence can be used to verify if the receiver has achieved a position fix and may be used in TTFF measurements. The GSV sentence provides the
C/N
0
(carrier-to-noise) ratios for each satellite that the receiver is tracking, which may be used for sensitivity tests.
Sensitivity
GPS receivers usually have two sensitivity figures specified: Acquisition Sensitivity and
Signal Tracking Sensitivity. Acquisition Sensitivity specifies the lowest power level at which the receiver is able to achieve a posit ion fix. Signal Tracking Sensitivity is the lowest power level at which a receiver is able to track an individual satellite.
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4 -9
4.1.6.A
Testing
Signal Tracking Sensitivity
Perform the following steps for signal tracking sensitivity test.
1
2.
3.
4.
STEP PROCEDURE
If connecting GPSG-1000 via Antenna Coupler, perform Antenna Coupler
Installation procedure Section 4.1.1. If directly connecting GPSG-1000 to GPS receiver under test, proceed to step 2.
Perform Setup procedure Section 4.1.2.
Select Launch Bar tab to display launch bar. Select SV PRN function key to display the SV PRN Function Window. The GPS SV’s in view will be displayed in a table.
Turn ON a single high elevation SV by selecting ON/OFF field to ON in the SV line and then select Apply. Select the close icon to close the Function Window.
5.
6.
Fig. 4-2 SV PRN Single SV Selection
Select RF Level and set to -136 dBm.
NOTE : This is 6 dB above the typical GPS receiver positional tracking sensitivity
of -142 dBm. If the active antenna is not in circuit, the gain of the
antenna should be subtracted from these figures.
Reduce the RF level in 0.1 dB increments until the specified C/N
0 is displayed on the receiver test page or read from the receiver using the NMEA-183 protocol.
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4 -10
Testing
4.1.6.B
Fig. 4-3 Simulation Function Window
Acquisition Sensitivity
Perform the following steps for acquisition sensitivity test.
1
2.
3.
4.
5.
6.
7.
STEP PROCEDURE
If connecting GPSG-1000 via Antenna Coupler, perform Antenna Coupler
Installation procedure Section 4.1.1. If directly connecting GPSG-1000 to GPS receiver under test, proceed to step 2.
Perform Setup procedure Section 4.1.2.
Select Launch Bar tab to display launch bar. Select SV PRN function key to display the SV PRN Function Window. The GPS SV’s in view will be displayed in a table.
Turn ON all SV’s by selecting ON/OFF field to ON in each SV line, then select
Apply . Select the close icon to close the Function Window. On the Setup
Simulation Function Window Select PRN Signal drop down menu. Select
VARIABLE to ensure the relative SV signal levels are set proportional to the respective pseudo ranges
Select RF Level and set to -136 dBm.
NOTE : This is 6 dB above the typical GPS receiver positional tracking sensitivity
of -142 dBm. If the active antenna is not in circuit, the gain of
the antenna should be subtracted from these figures.
Increase the RF Level in steps of 0.5 dB, until positional fix is displayed on the receiver or read from the receiver using the NMEA-183 protocol. Allow several minutes at each power level.
Increase the RF Level in steps of 0.5 dB until the positional fix is displayed on the receiver or read from the receiver using the NMEA-183 protocol. Allow several minutes at each power level.
NOTE : This is 6 dB above the typical GPS receiver positional tracking
sensitivity of -142 dBm. If the active antenna is not in circuit, the gain of
the antenna should be subtracted from these figures.
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4 -11
4.1.6.C
4.1 .7
Testing
C/N
0
Measurement O ptions
In scenarios where measurement speed is important, such as a production environment, you can use a higher C/N
0
value and extrapolate the sensitivity information from the result.
There is a linear relationship between RF power and C/N
0 alternative to measuring the receiver’s C/N
0
ratio, refer to table 4-2. As an
ratio at the given sensitivity level, it is possible to derive sensitivity based on the C/N
0 receiver C/N
0
at a different power level. Typical
ratio is 28 to 32 dB-Hz to achieve a position fix. If the receiver reports a C/
N
0
value of 28 dB-Hz at -145 dBm, it also reports a C/N
0
value of 43 dB-Hz at -130 dBm.
NOTE: It is important that a given receiver is first characterized by measuring the
acquisition sensitivity to ensure that receiver self-interference (e.g. spurs) or
digitisation noise, does not adversely effect the C/No figure before applying this
technique.
While the exact RF level used to measure sensit ivity varies from one receiver to the next, the ratio of the receiver of C/N
0
to RF power level is perfectly linear.
RF Level
-110.0 dBm
-115.0 dBm
-120.0 dBm
-125.0 dBm
-130.0 dB
-135.0 dB
-140.0 dB
Receiver C/N
0
56 dB –Hz
56 dB –Hz
53 dB –Hz
48 dB –Hz
43 dB –Hz
38 dB –Hz
33 dB –Hz
-145.0 dB 28 dB –Hz
Table 4-2 Typical Receiver C/N
0 as a function of RF level
NOTE: When a high input level is used to stimulate the C/N
the maximum possible C/N
0
0
ratio, the receiver reports
value allowed by the chipset. Typically this figure is
between 54 to 66 dB -Hz, (56 dB - Hz in Table 4-2 example).
Measu ring Time to First Fix (TTFF) and Position Accuracy
TTFF and position accuracy measurements are important parameters in GPS receiver testing. In many GPS applications, the time it takes for the receiver to return its actual location can significantly affect the receiver’s usability. In addition, the accuracy with which a receiver returns its reported location is important.
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4 -12
Testing
For a receiver to obtain a position fix, it must download the almanac and ephemeris information from the satellite through a navigation message. Because it takes 30 seconds for a receiver to download an entire GPS frame, a “cold start” TTFF condition can take anywhere from 30 to 60 seconds.
Signal strength also is a factor in correlation lock time and hence TTFF.
Fig. 4-4 TTFF vs. Signal Strength
Many receivers specify several TTFF conditions, including Acquisition (cold and warm start), Reacquisition (hot start) and Positional Accuracy.
4.1.7.A
Acquisition (cold start)
Under this condition the receiver does not have any current Almanac or Ephemeris data and has no memory of previous location. Firstly, at least one GPS frame must be downloaded from each of the SV’s in view however, as the receiver does not even know it approximate location and hence what SV’s may be in view, this requires all SV PRN codes to be searched, over 5000 Hz doppler frequency shift. Most modern receivers achieve a position fix from a cold start condition in 30 to 60 seconds. In older receivers this process may take several minutes.
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4 -13
Testing
Perform the following steps for Acquisition (cold start) TTF measurement.
1.
2.
3.
4.
5.
6.
7.
8.
STEP PROCEDURE
If connecting GPSG-1000 via Antenna Coupler, perform Antenna Coupler
Installation procedure Section 4.1.1. If directly connecting GPSG-1000 to GPS receiver under test, proceed to step 2.
Perform Setup procedure Section 4.1.2.
Ensure GPS receiver is in cold start mode i.e. no almanac or ephemeris in memory.
Select Launch Bar tab to display launch bar. Select SV PRN function key to display the SV PRN Function Window. The GPS SV’s in view will be displayed in a table (Fig 4-4).
Turn ON all SV’s by selecting ON/OFF field to ON in each SV line and then select
Apply. Select the close icon to close the Function Window.
On the Setup Simulation Function Window select PRN Signal drop down menu.
Select VARIABLE, this ensures the relative SV signal levels are set proportional to the respective pseudo ranges.
Select RF Level and set to the receiver manufacturers TTFF RF level.
Select Run key to restart simulation and measure the Time to Fix (TTF).
4.1.7.B
Acquisition (warm start)
The receiver has some almanac information that is less than one week old but does not have any ephemeris information.
NOTE: Ephemeris information is only valid for 4 hrs. Typically, the receiver knows the
time to within 20 seconds and the position to within 100 km. Most modern GPS
receivers achieve a position fix from a warm condition in less than 60 seconds
but can sometimes achieve a position fix in much less time.
Perform the following steps for Acquisition (warm start) TTF measurement.
1,
2.
3.
4.
5.
6.
7.
8.
STEP PROCEDURE
If connecting GPSG-1000 via Antenna Coupler, perform Antenna Coupler
Installation procedure Section 4.1.1. If directly connecting GPSG-1000 to GPS receiver under test, proceed to step 2.
Perform Setup procedure Section 4.1.2.
Ensure GPS receiver is in warm start mode i.e. no ephemeris in memory or receiver has not seen an ephemeris for over 4 Hrs.
Select Launch Bar tab to display launch bar. Select SV PRN function key to display the SV PRN Function Window. The GPS SV’s in view will be displayed in a table.
Turn ON all SV’s by selecting ON/OFF field to ON in each SV line and select
Apply. Select the close icon to close the Function Window.
On the Setup Simulation Function Window select PRN Signal drop down menu.
Select VARIABLE, this ensures the relative SV signal levels are set proportional to the respective pseudo ranges.
Select RF Level and set to the receiver manufacturers TTFF RF level.
Select Run key to restart simulation and measure the Time to Fix (TTF).
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4 -14
4.1.7.C
4.1.7.D
Testing
Reacquisition (hot start)
The receiver has up-to-date almanac and ephemeris information, has not been turned off for more than two hours and has not moved location more than 100m. In this scenario, the receiver needs to obtain only timing information from each SV to return its position fix location. Most modern GPS receivers return a position fix from a hot start condition within
0.5 to 20 seconds.
Perform the following steps for Reacquisition (hot start) TTF measurement.
1.
2.
3.
4.
5.
6.
7.
8.
STEP PROCEDURE
If connecting GPSG-1000 via Antenna Coupler, perform Antenna Coupler
Installation procedure Section 4.1.1. If directly connecting GPSG-1000 to GPS receiver under test, proceed to step 2.
Perform Setup procedure Section 4.1.2.
Select Launch Bar tab to display launch bar. Select SV PRN function key to display the SV PRN Function Window. The GPS SV’s in view will be displayed in a table.
Turn ON all SV’s by selecting ON/OFF field to ON in each SV line and select
Apply. Select the close icon to close the Function Window.
On the Setup Simulation Function Window select PRN Signal drop down menu.
Select VARIABLE, this ensures the relative SV signal levels are set proportional to the respective pseudo ranges.
Select RF Level and set to the receiver manufacturers TTFF RF level.
On the Simulation Function Window select the Run key to start the simulation.
Wait until a position fix is achieved and select the Stop Key.
Wait 60 seconds and then select Run key to restart simulation and measure the
Time to Fix (TTF).
TTFF Accuracy
As GPS satellites circle the earth every 12 hours, the range of available satellites varies substantially throughout the course of one day. TTFF and position accuracy are usually specified at a specific power level and to ensure that your receiver returns the appropriate result under a broad range of conditions it is useful to verify the accuracy of both of these specifications under a variety of circumstances.
The GPSG-1000 allows the user to enter a specific UTC time, which correlates with the almanac loaded in the test set. This feature allows a 3D position to be entered, which is then simulated utilizing either optimal geometry satellites automatically determined, or user selected satellites, available in that location, at that time, thereby providing a means to verify receiver positional accuracy under variable conditions.
NOTE: As GPS and Galileo time are different, the GPSG-1000 allows a common frame of
reference by utilizing UTC time for testing.
When measuring TTFF, first start the GPSG-1000. After five seconds, manually place the receiver into “cold” start mode. Once the receiver obtains a position fix, it reports the
TTFF information. Example results for Cold and Hot TTFF are shown in Table 4-3.
All table simulations utilize the same 3D position.
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4 -15
Testing
Initial UTC
10:14:02m
14:06:18
16:12:01m
18:32:22
Average
Standard DEV
4.1.7.E
Cold TTFF (S)
38.21
32.01
Hot TTFF (S)
1.30
0.52
Maximum SV C/No
46
49
SV’s
6,9,12,14,2
16,21
33.09
36.45
0.60
1.21
47
46
34.94
0.90
47
2.88
0.40
1.41
Table 4-3 TTFF Values for Four Simulations at Different UTC
11,4,8
24,9,7,15
Positional Accuracy
3D position accuracy and repeatability can be determined by creating simulations at various UTC’s. It is important to test accuracy at various UTC’s, because the available satellites and their geometries, change substantially even over the course of several hours. An example of latitude, longitude and altitude information, taken at four different
UTC’s, is shown in Table 4-4.
Initial UTC Latitude Longitude Alt (MSL)
10:14:02m
14:06:18
16:12:01m
37.658331
37.658325
37.658320
-97.438891
-97.438888
-97.438887
603.000000
597.000000
598.000000
18:32:22
Average
SIM Position
37.658310
34.94
Standard DEV 2.88
SIM Position DEC 2.88
-97.438891
97.438889
0.00000156
-97.438889
-
601.000000
599.750000
2.75378527
2.88
97:96:20 E 600.000000
Table 4-4 Horizontal Accuracy for Various UTC Simulations
Horizontal
Error (m)
0.268341
0.900046
1.457469
2.559818
1.296419
.0972312
Table 4-4 shows that you can calculate horizontal error in meters absolutely based on the simulated position. The horizontal error is determined from the equation:
The accuracy that a receiver can attain, is highly dependent on the available satellites that it has to lock to. Whilst a receiver’s accuracy will vary over the course of several hours (when satellites change), the positional repeatability for a given UTC will usually result in only a small deviation. With the GPSG-1000, you can perform multiple trials of a particular simulated 3D position. This also can confirm that the GPSG-1000 does not add uncertainty to the simulated GPS signal.
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4 -16
4.1 .8
Testing
RAIM Testing and SV Geometry
The orbital characteristics of SV’s within a GPS constellation are contained in the transmitted almanac and ephemeris data. The GPSG-1000 does not permit the user to directly change individual SV orbital parameters, therefore individual SV Elevation and
Azimuth, at any UTC within the simulation, are determined by almanac and the ephemeris generated from the almanac.
RAIM requires at least 5 SV’s to be in view and monitors specific accuracy boundaries which if crossed, will initiate specific alerts. Positional accuracy is dependent on SV geometry, examples of poor g eometry are groups of SV’s with azimuth angles close together and/or groups of SV’s with low elevation angles. Positions with low elevation
SV ‘s will also exhibit low relative RF Levels, due to the longer pseudo ranges. Due to the
SV orbital plane inclination of 55 deg, positions in temperate latitudes, the equator and polar regions.
Temperate latitudes exhibit SV azimuths that range in an arc either side of 90 and 270 degs.
Equator exhibits SV azimuths through a full 360 degs and elevations up to 90 deg.
Polar regions at 0 and 180 deg. Polar regions are devoid of satellites. Polar positions exhibit SV elevations that are low on the horizon.
Fig. 4-5 Global SV Tracks
The simulated position and Almanac/Ephemeris UTC, will determine the individual SV’s elevation, azimuth and RF level. The SV PRN Elevation and Azimuth indications are used to select combinations of SV’s that exhibit poor geometry for RAIM testing.
A bad geometry scenario may be setup in the SV PRN table by selecting only low elevation SV’s, only SV’s with closely spaced azimuths or only high elevation SV’s.
Alternatively polar positions may be simulated, which inherently have low elevation SV’s.
SV health may be set to BAD to ensure the receiver does not use that SV.
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4 -17
Testing
THIS PAGE INTENTIONALLY LEFT BLANK.
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4 -18
Chapter 5 - Maintenance
5.1
5.1 .1
5.1 .2
5.2
5.2 .1
INTRODUCTION
Visual Inspectio ns
Visual inspections should be performed periodically depending on operating environment, maintenance and use.
External Cleaning
1.
2.
3.
4.
5.
6.
STEP PROCEDURE
Clean front panel buttons and display face with soft lint-free cloth. If dirt is difficult to remove, dampen cloth with water and a mild liquid detergent.
Remove grease, fungus and ground-in dirt from surfaces with soft lint-free cloth dampened (not soaked) with isopropyl alcohol.
Remove dust and dirt from connectors with soft-bristled brush.
Cover connectors, not in use, with suitable dust cover to prevent tarnishing of connector contacts.
Clean cables with soft lint-free cloth.
Paint exposed metal surface to avoid corrosion.
MAINTENANCE PROCEDURES
Battery Replacement
Perform the following steps to replace battery:
4.
5.
6.
1.
2.
3.
STEP PROCEDURE
Verify the GPSG-1000 is OFF and not connected to AC power via the AC Adaptor.
Place the GPSG-1000 on a flat surface, lower side up.
Lift the battery cover Pull Tab to a vertical position to release the Battery Cover and lift away from the Case Assembly.
NOTE: Some batteries may be fitted with a sliding catch. Depress catch to
release battery. Tip the unit backwards to release the battery.
Remove the battery from the battery housing (Fig 5-1).
Install new battery in the battery housing.
Replace the battery cover on the case assembly by locating the lipped end of the cover in the case assembly. Lift the pull tab and push the battery cover down, ensuring the catch engages. Release the pull tab and ensure battery lays flat inside the recess.
NOTE: Some batteries may be fitted with a sliding catch. Depress catch to
install the battery.
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5 -1
Testing
DISPOSE OF OLD BATTERY ACCORDING TO LOCAL STANDARD SAFETY
PROCEDURES.
5.2 .2
Fig. 5-1 Battery Replacement
GPSG-1000 Software Update Procedure
Perform the following steps to Update GPSG-1000 Software via the USB port using a USB memory device * :
NOTE: A Service Information Letter (SIL) is released with each new software release.
The SIL contains important information regarding the software update content,
and the software update process. The SIL should be read carefully before any
update is attempted.
6.
7.
8.
1.
2.
3.
STEP PROCEDURE
Using your PC, obtain the latest software update zip file from Aeroflex.
Insert a USB memory device* into the PC and copy the zip file to the root directory of the USB memory device.
Remove any AEROFLEX directories that may reside on the root directory of the
USD memory device.
NOTE: It is recommended that a blank USB device be used for this procedure.
4.
5.
Unzip the file onto the root directory of the USB memory device.
Upon completion you will have an Aeroflex/Common/ directory that will contain all the rpm files for the update.
Safely remove the USB memory device from the PC.
Power up the GPSG-1000.
Once booted, select System then select System Update from the drop down menu.
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5 -2
Testing
9.
STEP PROCEDURE
Insert the USB memory device in USB Host 1 or Host 2 Port.
USB
Host 1
10.
11.
12.
13.
Fig. 5-2 USB Ports
Wait 5 to 10 seconds for the device to be recognized and select
Copy from USB .
** The status screen should indicate ‘Copying Software Update’.
NOTE: This step may take several minutes
NOTE: RPMs with older version numbers will not be displayed.
NOTE: Once all of the files have been copied from the USB Memory Device to the
GPSG-1000 internal memory, the files to be updated will be displayed in
the RPM LIST window and the message FILES ARE READY TO INSTALL
will be displayed in the STATUS window.
Select Install Software . The update will start and the progress screen appears.
When all RPM files have been installed a pop up will be displayed instructing the operator to PLEASE CYCLE POWER ON THE UNIT. To cycle power on the unit press and hold the Power On button on the front of the GPSG-1000 for one second and release.
Note: During the update process the system is performing many operations
and may take up to 45 seconds to respond to the power down request.
Remove the USB memory device and follow the instructions displayed on the unit.
* Recommended USB memory Device: Aeroflex PN 67325.
** If you experience a USB Error when trying to copy from USB, the USB memory
device being used may not be compatible with the GPSG-1000.
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5 -3
5.2 .3
Testing
GPSG-1000 Debug Files
Debug Files:
If the GPSG-1000 encounters a problem during the boot process and is unable to boot up properly, a debug file may be obtained from the GPSG-1000 and sent to Aeroflex to assist in determining the cause of the boot issue.
To obtain a copy of the debug files, install a USB memory device into one of the USB ports on the GPSG-1000. Press the power button to turn on the GPSG-1000. During the boot process two text files will be created on the USB Memory Device (Fig. 2-5). One file is called “gps1000rs232.txt”; and the other file is called “gps1000last_rs232.txt”; these files contain the latest debug files.
Each time the GPSG-1000 is booted with the USB Memory Device installed in one of the
USB ports, the debug files are overwritten with the latest boot information. The information contained in the debug file is not intended for use by the user. Both files should be sent to Aeroflex if suppo rt is being requested for a boot issue.
Fig. 5-3 Text files displayed on USB Memory Device
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5 -4
5.2 .4
Testing
Identifyin g Installed Software V ersion
Perform the following steps to identify the software version installed in the GPSG-1000.
14.
STEP PROCEDURE
Press the Power On button to turn the test set on.
.
15.
16.
Allow the test set to complete the boot process, approximately 5.5 mins.
Open the Launch Bar by touching the light gray bar located on the left side of the
User Interface and scroll down to the System function key.
17.
18.
STEP PROCEDURE
Touch the System function key to open the System sub-menu and select System
Update.
In the Version window the unit serial number and currently installed software version number is displayed. In the following example, “1000372866” is the unit serial number, and “2.0.0,201111221441” is the currently installed software version number.
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5 -5
5.2 .5
Testing
GPSG-1000 Almanac Update
Perform the following steps to Update GPSG-1000 Almanac using a USB memory device * :
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
STEP PROCEDURE
Obtain the current GPS almanac for the week from the United States Coast Guard
Navigation Center at http://www.navcen.uscg.gov/?pageName=gpsAlmanacs and save the file as “ current.alm
” or as “ weekXYZ.alm
” with XYZ being the current almanac week (week617.alm).
Copy the almanac file, named “ current.alm
” to the USB memory device (Aeroflex
P/N 67325) under the directory name of Aeroflex/almanacs/ plus almanac file name (/Aeroflex/almanacs/week617.alm).
Power up the GPSG-1000.
Select System , then select System Update from the drop down menu on the
GPSG-1000.
Insert the USB memory device into USB Host 1 Port or Host Port 2.
Wait 5 to 10 seconds for the device to be recognized and then select Copy from
USB .
The Almanac file will be copied to the GPSG-1000.
The status message should read ‘Upgrade Done’.
Remove the USB memory device.
Proceed to Setup window, then press Almanac Source . Press File , then select the newly loaded almanac file to load.
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5 -6
5.2.6
Testing
Maintenance Function Windows
Selecting the Maintenance icon from the Launch Bar Menu will display the Maintenance sub-menu. The Maintenance sub-menu contains the Calibration and Diagnostics icons.
Fig. 5-4 Maintenance Menu
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5 -7
5.2.6.A
Testing
Calibration Function Window
Selecting Calibration from the Maintenance sub-menu will display the Calibration
Password Entry Window. The Calibration Function Window is password protected.
Contact Aeroflex for the default password. Enter the password to open the Calibration
Function Window.
Fig. 5-5 Calibration Password Window
Control Component
Password
Cancel
OK
Change
D e s c r i p t i o n
Alpha Numeric Pad: Enter password to open the Calibration
Function Window.
NOTE: Contact Aeroflex for the default password.
Closes the Calibration Password Window.
After the Calibration Password has been entered, pressing OK will validate the password and open the Calibration Window if the password is accepted.
NOTE: Invalid Password is displayed if the password is entered incorrectly.
Opens Change Password Window. Enter old password, new password and reenter new password to change the password and open the Calibration Function Window.
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5 -8
5.2.6.B
Testing
Diagnostics Function Window
Selecting Diagnostics from the Maintenance sub-menu will display the Diagnostics
Function Window. The Diagnostics Function Window provides control for generating test signals, with specific power and frequency parameters.
Fig. 5-6 Diagnostics Function Window
Control Component
Mode
Frequency
Amplitude
Description
Drop down selections:
OFF - Diagnostics output disabled and simulation is allowed.
CW - Diagnostics output enabled, output is CW and simulation is locked.
MODULATED - Diagnostics output enabled, output is modulated GPS signal and simulation is locked.
Drop down selections: 1176.45 MHz, 1207.14 MHz, 1227.60
MHz, 1278.75 MHz or 1575.42 MHz.
Numeric pad: Power in dBm. Range -93 dBm to +155 dBm
DIRECT or -68 dBm to -130 dBm COUPLER
Doppler Error
EXT REF OUT
Numeric Pad: +/- 5000Hz in 1Hz increments.
Drop down selections: ON or OFF.
Reference Sources Drop down selections: INT or EXT.
LOG AMP Displays the output from the internal up convertor module.
Displayed in dB.
Read
PLL Lock Status
Reads the output from the internal up convertor module.
Indicates the state of the LO, 800 Mhz, EXT. REF and EXT.
REF DET. ON (Green) indicates locked condition, OFF (Gray) indicates unlocked condition.
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5 -9
5.2.7
Testing
System Function Windows
Selecting the System icon from the Launch Bar Menu will display the System sub-menu.
The System sub-menu contains the Options, System Configuration and System Update icons.
Fig. 5-7 System Menu
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5 -10
5.2.7.A
Testing
Options Function Window
Selecting Options from the System sub-menu will display the Options Function Window.
The Options Function Window provides control for installing or removing options and displays currently installed options.
Fig. 5-8 Options Function Window
Control Component
Copy from USB
Copy from Server
Install License
Remove License
Description
Initiates Copy of Option License files from a USB memory device installed in USB Host 1 or USB Host 2.
Initiates Copy of Option License files from a server.
NOTE: Factory use only.
Installs Option License files that have been copied to the internal memory.
Removes Option License files.
NOTE: This will permanently remove installed options.
Display Component
Status
Serial Number
Unique ID
Option
User
Installed
Expires
Server IP
Description
Displays status messages to inform the user of progress or errors.
Displays the serial number of the GPSG-1000.
Displays the Unique ID of the GPSG-1000.
Displays installed options.
Displays User log-in ID.
NOTE: Default is ALL if no user login required.
Displays date option was installed.
Displays date option expires.
NOTE: If no expiration date displays -1.
Numeric Pad: Enter the Server IP address.
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5 -11
5.2.7.B
5.2.7.C
Testing
System Configuration Function Window
Selecting System Configuration from the System sub-menu will display the System
Configuration Function Window. The System Configuration Function Window displays five selectable tabs across the top of the screen. Status, Hardware, UI Options, Network and
Date/Time.
Status
The Status tab displays test memory status, operating time, hardware module temperatures and provide internal SD card formatting control.
Fig. 5-9 System Configuration - Status
Display Component
Operating Time
Memory Available
Description
Displays the total operating time in hrs: mins:secs since power up.
Displays memory available to software resources in GB, MB or
KB.
Displays total test set memory in GB, MB or KB.
Memory Total
Disk Space Available Displays remaining disk space available in GB, MB or KB for settings and profile storage.
Disk Space Total Displays total test set disk space in GB, MB or KB.
RF Temperature
Power Supply
Temperature
Displays the current RF card temperature in degrees Celsius.
Displays the current power supply module temperature in degrees Celsius.
Battery Temperature Displays the current battery pack temperature in degrees
Celsius.
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5 -12
Testing
Display Component
Slot 1 MIC284
Temperature
Slot 1 OMAP
Temperature
Digital Board
Temperature
Description
Displays the current PXI slot 1 controller MIC284 temperature in degrees Celsius.
Displays the current PXI slot 1 controller OMAP processor temperature in degrees Celsius.
Displays the current PXI digital board temperature in degrees
Celsius.
Control Component
Format SD
Description
Formats the internal SD memory card overwriting all stored data.
NOTE: The user will be prompted YES or NO prior to execution of formatting.
Caution: Formatting will result in complete irretrievable loss of almanac, route, setting, Nmea, Kml, and waypoint data
5.2.7.D
Hardware
The Hardware tab displays hardware module/board identification, version and software revision numbers for configuration control purposes.
Fig. 5-10 System Configuration - Hardware
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5 -13
Testing
Display Component Description
Digital Board Card ID Displays digital board card ID number
Digital Board Card
Revision
Displays digital board card version number
Digital Board Bus
Firmware Version
Displays digital board firmware version number
Digital Board
Application Firmware
Version
Displays digital board application firmware version number
Upconverter Card ID Displays upconverter card ID number
Upconverter Card
Revision
Upconverter
Firmware Version
Displays upconverter card revision number
Displays upconverter firmware version number
RF Combiner Card ID Displays RF combiner card ID number
RF Combiner Card
Revision
RF Combiner
Firmware Version
Displays RF combiner card revision number
Displays RF combiner card firmware version number
Slot 1 PCI Net
Version
Displays PCI net version number
Slot 1 CPLD Version Displays Slot 1 CPLD version number
Slot 1 FPGA Version Displays Slot 1 FPGA version number
Slot 1 Board Revision Displays Slot 1 Board Revision number
Power Supply
Version
Displays power supply version number
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5 -14
5.2.7.E
Testing
UI Options
The UI Options tab controls the screen backlight level.
Fig. 5-11 System Configuration – UI Options
Control Component
Backlight
Description
Move the slider to the right to increase backlight level.
Move the slider to the left to reduce backlight level.
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5 -15
5.2.7.F
Testing
Network
The Network tab controls the test set Ethernet adaptor local area connection settings.
The Ethernet bus is used for remote control of the test set.
Fig. 5-12 System Configuration – Network
Control Component
IP Address
Subnet Mask
Gateway
DNS Server
Network Mode
Description
Numeric pad: IP address, entry in the format 10.200.120.148
(example).
Numeric pad: Subnet mask, entry in the format 255.255.255.0
(example).
Numeric pad: Gateway, entry in the format 10.101.0.1
(example).
NOTE : This field is only active when Network Mode = DHCP.
Connection specific Domain Name Server suffix.
NOTE : Reserved for future use.
Drop down menu: Selections
Network Off – Disables Ethernet adapter.
DHCP – Uses dynamically allocated address from DHCP server.
Static IP - Uses entered static IP address.
NOTE : Sever will populate IP Address, Subnet Mask and
Gateway fields automatically.
NOTE : The unit must be connected to a LAN before any change to this field is allowed.
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5 -16
5.2.7.G
Testing
Date/Time
The Date/Time tab controls the test set date /time clock parameters.
Fig. 5-13 System Configuration – Date/Time
Control Component
Time
Date
Description
Numeric pad: Time entry in the 24 Hour format HH:MM:SS.
Numeric pad: Date entry in the format MM:DD:YYYY.
NOTE: The unit time and date will be automatically updated once a 3D fix is registered by the unit’s internal GPS receiver.
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5 -17
Testing
THIS PAGE INTENTIONALLY LEFT BLANK.
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5 -18
Chapter 6 - Principles of Operation
6.1
6.1.1
PRINCIPLES OF OPERATION
GPSG-1000
Satellite Simulation
The orbit parameters for each satellite are configurable in terms of the standard
Keplerian (almanac) elements. The almanac used for simulation may selected from a list, maintained by a file management system. The files may obtained from the built in GPS receiver as a current almanac load or may be loaded from a USB flash drive in Yuma.alm format.
The standard Keplerian elements (almanac) are used to calculate the enhanced Keplerian
Elements (ephemeris), which are in turn used to generate the satellite motion, and are broadcast as part of the navigation message.
As almanac data is typically valid for several days, the GPSG-1000 does not update the standard Keplerian (almanac) elements during the course of the simulation.
The GPSG-1000 computes the enhanced Keplerian (ephemeris) elements by extrapolation of the configured standard Keplerian (almanac) elements. Any enhanced
Keplerian elements not included in the standard Keplerian elements are set to zero. The
GPSG-1000 generates updated enhanced Keplerian (ephemeris) elements at a fixed time interval of 4 hours, this being the update rate supported by both GPS and Galileo.
The GPSG-1000 generates in real time the positions of all simulated Satellites i.e. positions are not be pre-computed for the entire simulation run.
Satellite Selection
For each simulated GNSS system the GPSG-1000 will perform an independent satellite selection process and if the total number of visible satellites exceeds the maximum number of hardware channels allocated to that system, then the GPSG-1000 will select those satellites which approximate the minimum DOP for that system. The GPSG-1000 updates its satellite selection every 60 minutes.
NOTE: In the case of the 6 channel GPSG-1000, with large numbers of simulated ï€
satellites it becomes possible for many more satellites to be visible at the user ï€
location than there are available hardwa re satellite channels. If this happens the ï€
GPSG-1000 allocates channels on a 'best effort' basis but does allow the ï€
operator to override the selection manually.
The GPSG-1000 allows the operator to manually replace any selected satellite with another visible satellite from the same GNSS system, with the manually selected satellite remaining selected until it is no longer visi ble, or until it is manually replaced. The manually de-selected satellite will remain eligible for re-selection at the next automatic update.
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6 -1
6.1.2
Principals of Operation
GPS System
The NAVSTAR (Navigation Satellite Timing And Ranging) GPS (Global Positioning
System) is a satellite based navigation system offering precision navigation capability.
The system was originally designed for military use, funded and controlled by the U.S.
Department of Defense. Civilian access has been permitted to specific parts of the GPS.
GPS offers a number of features making it attractive for use in aircraft navigation.
Civilian users can expect a position accuracy of 100 m or better in three dimensions. The
GPS signal is available 24 hours per day throughout the world and in all weather conditions. GPS offers resistance to intentional (jamming) and unintentional interference. The equipment necessary to receive and process GPS signals is affordable and reliable and does not require atomic clocks or antenna arrays. For the GPS user, the system is passive and requires a receiver only, without the requirement to transmit.
GPS determines the position of the user by triangulation. By knowing the position of the satellite and the distance from the satellite, combinations of satellites can be used to determine the exact position of the rece iver. The fundamental means for GPS to determine distance is the use of time. Dist ance is computed by using accurate time standards and by measuring changes in time.
The GPS System is comprised of three segments:
•
•
•
Space Segment
Control Segment
User Segment
Spa ce S egment
Fr om Satel lites
L1 Carr ier S ignals
- time p ulses
- ep hem er is
- al manac
- satelli te health
- date, time
- establi she d ephemeri s
- cal cu lated alm an acs
- satell ite health
- tim e co rre ctio ns
From The
Gro und S tati on
User S egm ent
Fig. 6-1 GPS System Segments
Control Se gm ent
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6 -2
6.1.2.A
Principals of Operation
Space Segment
The Space segment consists of the GPS space vehicles (SV’s) or Satellites, nominally 24
SV’s plus spares. The terms SV and satellite shall be interchangeable in this document.
Each vehicle has a 12 hour orbit at 20,200 km above the earth and repeats same ground track daily. 5 to 12 SV’s are visible from anywhere on earth .
Fig. 6-2 GPS Satellite
Six orbital planes are used, each spaced equally around the earth, separated by 60 degrees (360 degrees/6 planes=60 degrees) and inclined 55 degrees from equatorial plane. The planes are named A to F. Each orbital plane hosts four satellites. These satellites are not spaced evenly on each plane. Spacing between adjacent satellites varies from 31.13 degrees to 119.98 degrees. Each plane exhibits a different angular spacing for the satellites resident to it.
A computer model determines the satellite spacing to accommodate a single satellite failure and still maintain optimal satellite geometry.
Fig. 6-3 GPS Satellite Orbital Planes
Fig. 6-3 shows the motion of nine satellites. The ground tracks show the movement of these satellites over a twelve hour period and the position of the satellites at one moment in time.
The ground tracks show a number of features. Each satellite follows a unique path over the ground. Also, every satellite operates between 55 degrees North and 55 degrees south.
The primary mission of GPS satellites is the transmission of precisely timed GPS signals and the data stream required to decode the signals to produce a position. The timing signals are referenced to atomic clocks, either cesium or rubidium.
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6 -3
Principals of Operation
With the GPS satellites in constant motion, the number of satellites in view and their relative location is dynamic. A 24 satellite configuration provides adequate satellite coverage to perform three-dimensional position fixing. Failures of satellites and/or the requirement for more than four satellites may result in inadequate satellite coverage.
Fig. 6-4 GPS SV Block Schematic
Fig. 6-5 GPS SV Signal Data Structure
Each GPS satellite transmits a unique signature assigned to it on the same carrier frequency. This signature consists of a Pseudo Random Noise (PRN) Code of 1023 zeros and ones, broadcast with a duration of 1 ms and continually repeated. The PRN code is exclusively OR’d (modulo 2 added on), with 50 bit/s Navigation Data (Nav Data). The combined code is then used to BPSK modulate a 1575.42 MHz carrier frequency. The resultant signal is spread spectrum.
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6 -4
6.1.2.B
Principals of Operation
Control Segment
Six unmanned monitoring stations are located throughout the world. Each Station constantly monitors and receives information from the GPS satellites and sends the orbital and clock information to the master control station. Five of these stations (except
Hawaii) have the ability to upload information to the GPS satellites
Colorado Springs is designated a Master Co ntrol Station (MCS). The MCS constantly receives GPS satellite, orbital and clock information from the monitor stations. The MCS makes precise corrections to the data as necessary and sends the information, known as ephemeris data, to the GPS satellites using ground based antennas.
6.1.2.C
6.1.3
Fig. 6-6 GPS Monitor Stations
•
•
The objective of the GPS control segment is:
• Maintain each of the satellites in its proper orbit through infrequent, small commanded maneuvers.
Make corrections and adjustments to the satellite clocks and payload as needed.
Track the GPS satellites and generate and upload navigation data to each of the
GPS satellites .
• Command major relocations in the event of satellite failure to minimize the impact.
User Segment
The signals broadcast from the GPS satellites form the means for a GPS receiver to perform the timing and distance calculations. GPS receivers are passive devices, meaning that signals are received only with no requirement or means to transmit.
GPS ranging signals are broadcast on two frequencies: L1 (1575.42 MHz) and L2 ï€
(1227.6 MHz). The L1 frequency is available for civilian use. The L2 frequency was designed primarily for Military use.
SPS Standard Positioning Service
The Clear Acquisition Code, or C/A, is the principal civilian ranging signal and is always broadcast in a clear or unencrypted form. The use of this signal is sometimes called the
Standard Positioning Service or SPS. This signal may be degraded intentionally but is always available. The signal creates a short Pseudo Random Noise (PRN) code
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6 -5
6.1.3.A
6.1.4
6.1.4.A
Principals of Operation broadcast a rate of 1.023 MHz. The satellite signal repeats itself every millisecond. ï€
The C/A code is also used to acquire the P Code.
PPS Precise Positioning Service
Protected Code or P Code: this is also known as the Precise Positioning Service. The P
Code is never transmitted in the clear and is encrypted with a W code. When encrypted the signal is know as P(Y) code and is not available to civilian users. The C/A PRN’s are unique for each satellite however, the P-code PRN is actually a small segment of a master P-code approxim ately 2.35 × 1014 bits in length (235,000,000,000,000 bits) and each satellite repeatedly transmits its assigned segment of the master code.
Position Calculation
•
•
•
•
•
Position calculations consists of the following elements:
•
•
Deciding which satellites to acquire and track
Code and frequency correlation
Measure distance to satellites
Obtain satellite positions
Adjust local clock bias
Perform triangulation calculations (Trilateration)
Adjust for time delay errors
SV’s to Acquire and Track
The L1 and L2 frequencies broadcast a GPS Navigation Message (Nav Data) as part of their signal. This low frequency (50 bits per second) data stream provides the receiver with a number of critical items required in determining a position. A data bit frame consists of 1500 bits divided into five, six second 300-bit subframes. A data frame is transmitted every thirty seconds. An entire set of twenty-five frames (125 subframes) makes up the complete Navigation Message that is sent over a 12.5 minute period.
Fig. 6-7 GPS Navigation Data
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6 -6
Principals of Operation
Subframes
Subframes 1 to 5 each provide a synchronization, hand-over word and a C/A code time ambiguity removal. The remainder of the data is formatted as follows:
Subframe 1:
Contains the time values of the transmitting satellite, including the parameters for correcting signal transit delay and onboard clock time, as well as information on satellite health and an estimate of the positional accuracy of the satellite.
Subframe 2 and 3:
Ephemeris.
Subframe 4:
Ionospheric model, UTC data, flags for each satellite indicating whether antispoofing is on, almanac (approximate satellite ephemeris allowing the receiver to select the best set of satellites or to determine which satellites are in view) and health information for satellite number 25 and greater.
Subframe 5:
Almanac and health information for satellite number 1 to 24 .
The reception and decoding of the data stream is performed automatically by a receiver without any intervention by the operator. The information within this data is critical to
GPS operation. If a GPS receiver has never seen the GPS constellation before and does not know its approximate location, the first action of the receiver is to acquire any SV in view. Once a satellite has been acquired, the almanac is downloaded.
Subframes 4 and 5 contain almanac informati on. Once the almanac is acquired, the information it contains is used to determine which satellites are in view and select the set of satellites with the best geometry. The almanac structure for one SV PRN is shown in
Fig. 6-8. Almanac data is typically updated every 24 hours. Data for a few weeks is also provided in case of a delay in update. Once a receiver has an almanac loaded in its memory, it can be used for a faster acquisition of satellites on the next occasion of use.
Once a satellite has been acquired, it’s ephemeris information can be obtained.
******** Week 572 almanac for PRN-03 ********
ID: 03
Health: 000
Eccentricity: 0.1350402832E-001
Time of Applicability(s): 405504.0000
Orbital Inclination(rad): 0.9279594421
Rate of Right Ascen(r/s): -0.8203642210E-008
SQRT(A) (m 1/2): 5153.669922
Right Ascen at Week(rad): 0.3102266431E+001
Argument of Perigee(rad): 1.020882249
Mean Anom(rad): -0.7818025351E+000
Af0(s): 0.5941390991E-003
Af1(s/s): 0.3637978807E-011 week: 572
Fig. 6-8 GPS Almanac
The almanac provides a basic description of each satellite orbit. Refer to Fig. 6-10. Two parameters are commonly displayed on GPS receivers which describe the basic position of a satellite relative to a GPS receiver at a specific location.
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6 -7
Principals of Operation
Elevation describes the angle of a satellite relative to the horizontal plane. If a satellite is directly above the point of observation on the ground, then the elevation is 90°. If the satellite is at the horizon, then the elevation is 0°.
Azimuth is the angle between a reference plane and a point. In the case of satellites the reference plane is the plane of the horizon based on true North. The Azimuth is the angle between the satellite and true North (North = 0° , East = 90°, South = 180°, West = 270°).
Of course many other parameters are used to define satellite orbit. Each satellite will downlink a more precise description of its orbit, which is contained in sub-frames 2 and 3, and is known as ephemeris. With this information the receiver can determine the satellite’s position at any time and combine this with the receiver distance from the satellite, yielding a GPS position.
6.1.4.B
Fig. 6-9 Satellite Relative Position
The health information transmitted in subframe 5, is critical to prevent a receiver from using the ranging information from a satellite that has been declared unfit for navigation purposes.
The remainder of the information found in the data stream (clock corrections, ionospheric model, UTC data) are used to resolve potential sources of GPS position errors.
Code and Frequency Correlation
The power of the received GPS signal in open sky is at least -160 dBW (-130 dBm).
ï€
The maximum of the spectral power density of the received signal is -190 dBm/Hz. ï€
The spectral power density of the thermal background noise is approximately ï€
-174 dBm/Hz (at a temperature of 290 K). Refer to Fig, 6-10. The maximum received signal power is approximately 16 dB below the thermal background noise level.
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6 -8
Principals of Operation
Fig. 6-10 GPS Received Signal
To recover the data from spread spectrum signal at the receiver, the energy spread over a wide bandwidth must be correlated or de-spread into a narrow bandwidth by frequency and code shifting. Fig. 6-11 shows the criticality of correlation in terms of recovering the signal.
Fig. 6-11 GPS Received Signal
Each GPS satellite transmits a unique PRN code. The receiver first demodulates received BPSK signal to extract the satellite PRN code overlaid with Nav Data. The receiver then generates a loca l copy of the PRN code and then shifts the timing of the local code by ï€
1 bit, relative to a receiver time mark, until all 1,023 bits of the local code are in phase
(correlated), with the PRN code received from the satellite. A modulo 2 addition process is used to recover the Nav Data.
If all 1,023 bit shifts have been tried without achieving correlation, the receiver local oscillator frequency is offset to the next value and the process is repeated. The reason for this frequency offset, is because satellites and receivers are in relative motion to one another and hence Doppler shift in the transmitted carrier frequency occurs. The transmitted signals can be shifted by up to +/- 5000 Hz at the point of reception.
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6 -9
Principals of Operation
The determination of the signal travel time and data recovery therefore requires not only correlation with all possible codes at all possible phase shifts, but also identification of the correct phase carrier frequency.
In the case of a receiver cold start, where the receiver does not have a current almanac loaded, every PRN would be tried until an SV is found in view, after which the almanac can be downloaded and used to determine which SV’s to acquire next. Because the search for the first SV may take some time, GPS receiver cold starts take appreciably longer than warm starts, where the GPS receiver has a current almanac stored in memory.
Fig. 6-12 GPS Code Correlation Process
Fig. 6-13 GPS Nav Data Recover by Moduo 2 Addition
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6 -10
Principals of Operation
The spectral power density of the received GPS signal lays at approximately 16 dB below the spectral power density of the thermal or background noise. The demodulation and despreading of the received GPS signal causes a system gain G of:
After despreading, the power density of the usable signal is greater than that of the ther mal or background signal noise.
6.1.4.C
Fig. 6-14 GPS Signal After De-spreading
Measuring Distance (Pseudo Range)
GPS satellites orbit 200km above the earth and are distributed in such a way that from any point on the ground there is line-of-sight contact to at least four satellites.
Each one of these satellites is equipped with onboard atomic clocks. In order to make them even more accurate, they are regularly adjusted or synchronized from various control points on Earth. GPS satellites transmit their exact position and onboard clock time to Earth.
These signals are transmitted at the speed of light (300,000 km/s) and therefore require approximately 67.3 ms to reach a position on the Earth’s surface directly below the satellite. The signals require a further 3.33 µs for each additional kilometer of travel. To establish position, all that is required is a receiver and an accurate clock.
By comparing the arrival time of the satellite signal with the onboard clock time the moment the signal was transmitted, it is possible to determine the signal travel time.
Distance = Velocity * Time: Velocity is 300,000 km/s and Time is the travel time of the signal.
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6 -11
Principals of Operation
To measure the travel time:
•
•
•
Receiver generates the same codes as the Satellite (PRN codes)
Measure delay between incoming codes and self generated codes
D = Speed of light * measured delay (Pseudo Range)
The first word of every single frame, the Telemetry word (TLM), contains a preamble sequence 8 bits in length (10001011) used for synchronization purposes, followed by 16 bits reserved for authorized users. As with all words, the final 6 bits of the telemetry word are parity bits.
The handover-word (HOW) immediately follows the telemetry word in each subframe. The handover-word is 17 bits in length (a range of values from 0 to 131071 can be represented using 17 bits) and contains within its structure the start time for the next subframe, which is transmitted as time of the week (TOW).
Fig. 6-15 GPS Subframe Hand-Over Word
The transmission time in the first bits of the preamble are provided in the Navigation
Message in the TOW Message of the previous frame. This time is given in Satellite Time.
Information in the Navigation Message allows translation into Receiver Time. If the preamble is validated, the arrival time of the first bits in the preamble is measured. ï€
This time is given in Receiver Time.
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6 -12
Principals of Operation
Due to the atomic clocks onboard the satellites, the time at which the satellite signal is transmitted is known very precisely. All satellite clocks are adjusted to be synchronized with each other and UTC (universal time coordinated). In contrast, the receiver clock is not synchronized to UTC and is therefore slow or fast by Δ t0 (clock bias). The sign Δ t0 is positive when the user clock is fast. The resultant time error Δ t0, causes inaccuracies in the measurement of signal travel time and the distance R. As a result, an incorrect distance is measured that is known as a pseudorange.
6.1.4.D
Fig. 6-16 GPS Pseudo Range
Obtain Satellite Positions
GPS receivers download an almanac into memory which defines where in the sky each satellite is, moment by moment. GPS satellites are constantly monitored by the U.S.
Department of Defense. Slight orbital errors are caused by gravitational pulls from the moon and sun and by the pressure of solar radiation on the satellites. Radar is used to check each satellite's exact altitude, positi on and speed. This information (ephemeris data), is then relayed back up to the respective satellite, which in turn transmits the ephemeris data in Nav Data subframes 2 and 3. Ephemeris data is updated every two hours and is valid for four hours.
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6 -13
6.1.4.E
Principals of Operation
Clock Bias
To solve the problem of clock bias, consider a receiver is placed on a straight line beneath two satellites. As the position of all GPS satellites is known via information contained in the almanac and ephemeris, the distance between any two satellites (S), is known. By measuring the travel times from each satellite, it is possible to exactly establish the distance (D) despite having an imprecise receiver clock, using the following formula:
ï€
D = ( Δ t1 – Δ t2) x c + S
2
S (known distance between satellites)
∆ t
1 ∆ t
2
6.1.4.F
D
Fig. 6-17 GPS Pseudo Range
In this example two pseudo ranges were employed to determine a position in one dimensional space. To calculate a position in two dimensional space, three pseudo ranges are required, Latitude, Longitude and Δ t.
To calculate a position in three dimensional space, four pseudo ranges are required;
Latitude, Longitude, Altitude and Δ t . The number of pseudo ranges (GPS satellites), must exceed the number of unknown dimensions by a value of one.
Triangulation Calculations (Trilateration)
Consider triangulation in 2D space. If location of point A is known, and the distance to point A is known, desired position lies somewhere on a circle.
Fig. 6-18 Triangulation using one known point
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6 -14
Principals of Operation
Distance to two points is known, desired position is in one of two locations
Fig. 6-19 Triangulation using two known point
Distance to three points is known, position is known.
Fig. 6-20 Triangulation using three known point
Consider triangulation in 3D Space. Distance to two points is known.
Fig. 6-21 Triangulation using two known points in 3D space
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6 -15
Principals of Operation
Distance to three points is known, position is known in 3D space.
6.1.4.G
Fig. 6-22 Triangulation using three known points in 3D space
Time Delay Errors
Sources of Time Delay Error are:
Ephemeris data :
The data concerning ephemeris errors may not exactly model the true satellite motion.
The disparity in ephemeris data can introduce 1 to 5 meters of positional error.
Ephemeris data is valid for a period of about 4 hours
Satellite clocks:
The data concerning the satellite’s four atomic clocks may not reflect the exact rate of clock drift. Distortion of the signal by measurement noise can further increase positional error. Clock drift disparity can introduce 0 to 2.5 meters of positional error and measurement noise can introduce 0 to 10 meters of positional error.
Receiver Clock Inaccuracies and Rounding Errors :
Despite the synchronization of the receiver clock with the satellite time during the position determination (compensation for clock bias), the remaining inaccuracy of the time still leads to an error of about 2 m in the position determination. Rounding and calculation errors of the receiver sum up approximately to 1 m.
Multipath:
GPS signals can also be affected by multi-pat h issues where the radio signals reflect off of surrounding terrain such as buildings, canyon walls, and hard ground. These delayed signals can result in periodic signal cancellation but typically they change dynamically with location and may just cause short term inaccuracy.
Fig. 6-23 Multipath Delays
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6 -16
6.1.4.H
Principals of Operation
Atmospheric Delays
Ionosphere:
The ionosphere is an atmospheric layer situated between 90 to 1000 km above the
Earth’s surface. The gas molecules in the ionosphere are heavily ionized. The ionization is caused mainly by solar radiation, hence the thickness of this layer varies during the course of the day. Signals from the satellites travel through a vacuum at the speed of light. However, in the ionosphere the velocity of these signals slows down due to the ionized gas, an effect called dispersion, which is frequency dependent.
Fig. 6-24 Atmospheric Delays
Ionospheric dispersion is one of the most significant error sources. These effects are smallest when the satellite is directly overhead and become greater for satellites nearer the horizon as the signal passes through the ionosphere at a shallow angle, hence a thicker band has to be traversed. Two methods can be used to correct for Ionospheric delays.
• Once the receiver's approximate location is known, a mathematical model can be used to estimate and compensate for these errors.
• Because ionospheric delay affects the speed of microwave signals differently based on frequency, a second carrier frequency, L2 can be used to measure atmosphere dispersion and apply a more precise correction to help compensate for this error. This is the method employed in military GPS receivers using L1 and
ï€
L2.
ï€
This can also be realized in more expensive civilian GPS receivers without decrypting the P(Y) signal carried on L2 by tracking the carrier wave instead of the modulated code. To do this on lower cost receivers, a new civilian code signal on L2 called L2C was added to the satellites. This new signal allows a direct comparison of the L1 and L2 signals u sing the coded signal instead of the carrier wave.
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6 -17
6.1.5
Principals of Operation
Troposphere:
The troposphere is the lower part of the eart h's atmosphere (0 -15km), that encompasses our weather. It's full of water vapor and varies in temperature and pressure and causes a variable but predictable delay. This delay is corrected using a simple model based on pressure, temperature and altitude.
The errors of the GPS system are summarized in table 6-1. The individual values are no constant values, but are subject to variances, all numbers are approximate values.
Altogether this sums up to an error of between ± 12 to ± 15 meters.
Type of Time Delay Error
Ephemeris Errors
Satellite Clock Errors
Positional Error
± 2.5 m
± 2 m
Multipath Delays
Receiver Clock Inaccuracies and
Rounding Errors:
± 1 m
± 1 m
Ionospheric Delays ± 5 m
Tropospheric Delays ± 0.5 m
Table 6-1 PS Positional Error Sources
GPS Timekeeping
Most clocks are synchronized to Coordinated Universal Time (UTC) however, the atomic clocks on the satellites are set to GPS time. GPS time is not corrected to match the rotation of the Earth, so it does not contain leap seconds or other corrections that are periodically added to UTC. GPS time was set to match Coordinated Universal Time (UTC) in 1980, but has since diverged. The lack of corrections means that GPS time remains at a constant offset with International Atomic Ti me (TAI) (TAI - GPS = 19 seconds). Periodic corrections are performed on the on-board clocks to correct relativistic effects and keep them synchronized with ground clocks.
The GPS navigation message data includes the difference between GPS time and UTC, which as of January 1, 2017 is 18 seconds due to the Leap second added to UTC
December 31, 2016. Receivers subtract this offset from GPS time to calculate UTC and specific time zone values. New GPS units ma y not show the correct UTC time until after receiving the UTC offset message.
The GPSG-1000 updates the values related to leap second changes that are within the navigation message data every 60 minutes. The timing of the leap second value updates are based on the simulation start time. Values related to the timing of upcoming leap seconds are stored in a data file within the GPSG-1000. Values related to announcing upcoming leap seconds to receivers are transmitted 60 days prior to the leap seconds rollover date, and are maintained for 60 days after the event.
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6 -18
Principals of Operation
The GPS-UTC offset field can accommodate 25 5 leap seconds (eight bits) which, given the current rate of change of the Earth's ro tation (with one leap second introduced approximately every 18 months), should be sufficient to last until approximately the year
2300. As opposed to the year, month, and day format of the Gregorian calendar, the GPS date is expressed as a week number and a seconds-into-week number.
6.1.6
Fig. 6-25 GPS v. UTC Time Format
The week number is transmitted as a ten-bit field in the C/A and P(Y) navigation messages, and so it becomes zero again every 1,024 weeks (19.6 years). GPS week zero started at 00:00:00 UTC (00:00:19 TAI) on January 6, 1980, and the week number became zero again for the first time at 23:59:47 TC on August 21, 1999 (00:00:19 TAI on
August 22, 1999).
To determine the current Gregorian date, a GPS receiver must be provided with the approximate date (to within 3,584 days) to correctly translate the GPS date signal. To address this concern the modernized GPS navigation message uses a 13-bit field, which only repeats every 8,192 weeks (157 years), thus lasting until the year 2137 (157 years after GPS week zero).
GNSS Accuracy
A GNSS receiver determines its Position (horizontal and vertical), its Velocity and the
Time from the signals of at least four satellites by means of triangulation. The precision of the computations by triangul ation depends on the constellation of all satellites of which the signals are taken into account (four or more). As the number and position of satellites will seldom be ideal, the maximum obtainable precision will be diluted in practice. Here we present the different terms of dilution of precision.
Dilution of precision (DOP) is a measure of the quality of the GPS data being received from the satellites. DOP is a mathematical representation for the quality of the GPS position solution. The main factors affecting DOP are the number of satellites being tracked and where these satellites are positione d in the sky. The effect of DOP can be resolved into HDOP, VDOP, PDOP and TDOP.
HDOP (Horizontal Dilution Of Precision) is a measure of how well the positions of the satellites, used to generate the Latitude an d Longitude solutions, are arranged. PDOP less than 4 gives the best accuracy, between 4 and 8 gives acceptable accuracy and greater than 8 gives unacceptable poor accuracy. Higher HDOP values can be caused if the satellites are at high elevations.
VDOP (Vertical Dilution Of Precision) is a measure of how well the positions of the satellites, used to generate the vertical component of a solution, are arranged. Higher
VDOP values mean less certainty in the solutions and can be caused if the satellites are at low elevations.
TDOP (Time Dilution Of Precision) is a measure of how the satellite geometry is affecting the ability of the GPS receiver to determine time.
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6 -19
6.1.7
Principals of Operation
PDOP (Positional Dilution OF Precision) is a measure of overall uncertainty in a GPS position solution with TDOP not included in the estimated uncertainty. The best PDOP
(lowest value) would occur with one satellite directly overhead a nd three others evenly spaced about the horizon. PDOP = SQRT(HDOP^2 + VDOP^2).
GDOP (Geometric Dilution Of Precision) is a measure of the overall uncertainty in a GPS position solution. GDOP = SQRT(TDOP^2 + HDOP^2 + VDOP^2) or in another form
GDOP = SQRT(PDOP^2 + TDOP^2). GDOP value should be less than 5.
The Position Accuracy = Dilution Of Precision (DOP) times Measurement Precision. So, if the Measurement Precision = 1m and the DOP = 5, then the best position accuracy will be
5m.
GNSS Augmentation
Augmentation of GNSS, is a method of improving the navigation system accuracy, reliability and availability through the integration of external information into the calculation process. SBAS (Satellite Based Augmentation System) and RAIM (Receiver
Autonomous Integrity Monitoring System) are GNSS augmentation systems.
Satellite Based Augmentation System (SBAS)
SBAS is a system that supports wide-area or regional augmentation through use of additional satellite broadcast messages that contain correctional data obtained from multiple ground stations at surveyed locations.
The effects of the ionosphere generally change slowly and can be averaged over time.
The effects for any particular geographical area can be easily calculated by comparing the GPS-measured position to a known surveyed location. This correction is also valid for other receivers in the same general location.
The data is transmitted via satellites in the SBAS system and is transmitted on the GPS
L1 frequency using a special pseudo-random number, allocated for SBAS use. This allows the civilian L1 C/A code receivers that support SBAS, to use the correctional data.
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6 -20
Principals of Operation
All SBAS satellites support the same protocols and therefore can support seamless augmentation from o ne region to another.
Fig. 6-26 SBAS Coverage
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6 -21
6.1.7.A
6.1.7.B
Principals of Operation
SBAS Systems
WAAS (W ide A rea A ugmentation S ystem)
Developed and managed by the FAA, to augment GPS, with the goal of improving its accuracy, integrity, and avail ability. WAAS is intended to enable aircraft to rely on GPS for all phases of flight, including precision approaches to any airport within its coverage area. The system communicates with several ground stations and provides atmospheric corrections & early warning of GPS failures. The data rate is higher that L1 C/A code at
250 Hz and two geostationary satellites provide area coverage.
EGNOS ( E uropean G eostationary N avigation O verlay S ystem)
Managed by the European tripartite group. Corrections for GPS and GLONASS
Similarly to WAAS, EGNOS is mostly designed for aviation users which enjoy unperturbed reception of direct signals from three geostationary satellites up to very high latitudes.
The use of EGNOS on the ground, especially in urban areas is limited due to relatively low elevation of geostationary satellites: about 30° above horizon in central Europe and much less in the North of Europe. To address this problem, ESA released in 2002
SISNeT, an Internet service designed for continuous delivery of EGNOS signals to ground users. SV PRN 126 is used for test purposes at this time (2010).
MSAS ( M ulti-Functional S atellite A ugmentation S ystem
Managed by the Japanese Civil Aviation Bureau (JCAB), a satellite navigation system which supports differential GPS, designed to supplement the GPS system by reporting
(then improving) on the reliability and accuracy of those signals. MSAS for aviation use was commissioned on September 27, 2007. Two geostationary satellites provide area coverage.
GAGAN ( G PS A ided G eo A ugmented N avigation)
The GAGAN system is a planned implementation of a regional Satellite Based Augmentation System
(SBAS) by the Indian government. It is a system to improve the accuracy of a GNSS receiver by providing reference signals. Two geostationary satellites will eventually provide area coverage. One SV is currently deployed, PRN 127.
RAIM (Receiver Autonomous Integrity Monitoring System)
A unique aviation requirement of GPS avionics is RAIM. While GPS provides the user with unparalleled levels of accuracy, one signific ant deficiency of GPS is integrity, or the ability of the system to provide a timely warning if the navigation solution is inaccurate or erroneous. Navigation systems prior to GPS, particularly aviation applications, provided a means to warn the aircraft that the signal was outside certain limits. For example, a
Category I ILS provides this warning within six seconds.
The only means available for the GPS system itself to provide the user with a warning of system unreliability is through the data message forming part of the GPS signal. The
“health” flag found in subframe 4 and 5 will alert the receiver to a failure of a GPS satellite.
The time lag from the beginning of the failure to when it is incorporated in the health flag
(up to eight hours) represents an unacceptably long period of time for aviation.
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6 -22
Principals of Operation
To overcome this, RAIM was developed and is a mandatory feature of all aviation-grade receivers. RAIM uses combinations of satellites to determine the receiver position.
Should a large discrepancy between position solutions occur, a RAIM alert is created rendering the GPS navigator unreliable. Different phases of flight use different values of
“integrity alarm limits” prior to issuing a RAIM alert.
The ability of a receiver to perform RAIM computations is dependent upon the number of satellites in view, their geometry and the mask angle which is dependent upon the ability of the antenna to track satellites near the horizon and any local terrain. Whereas GPS needs a minimum of four satellites to produce a three-dimensional position, a minimum of five satellites are required for RAIM. For this reason, RAIM may not be available in circumstances of poor satellite coverage or poor satellite geometry.
Enroute (oceanic, domestic, random ï€ and JV routes)
2.0 nm
Terminal
Phase of Flight Alarm Limit Time to Alarm
1.0 nm
30 sec
10 sec
RNAV Approach Non Precision 0.3 nm
Table 6-2 RAIM Alarms
10 sec
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6 -23
6.1.8
Principals of Operation
GPS Modernization Signals
A process of GPS system modernization is now underway, which involves the introduction of new signals to provide improvements in accuracy and integrity.
M C
6.1.8.A
Fig. 6-27 GPS Modernization Signals
L2CS
The L2CS system provides a civilian-use signal transmitted on a frequency other than the
L1 frequency used for the Coarse Acquisition (C/A) signal, and broadcast on the L2 frequency. Because it requires new hardware onboard the satellite, it is only transmitted by the so-called Block IIR-M and later design satellites. The L2CS signal is tasked with improving accuracy of navigation, providing an easy to track signal, and acting as a redundant signal in case of localized interference.
Unlike the C/A code, L2CS contains two distinct PRN code sequences to provide ranging information; the Civilian Moderate length code (called CM), and the Civilian Long length code (called CL). The CM code is 10,230 bits long, repeating every 20 ms. The CL code is 767,250 bits long, repeating every 1500 ms. Each signal is transmitted at 511,500 bits per second (bit/s); however, they are multiplexed together to form a 1,023,000 bit/s signal.
CM is modulated with the CNAV Navigation Message (see below), whereas CL does not contain any modulated data and is called a data-less sequence . The long, data-less sequence provides for approximately 24 dB greater correlation (~250 times stronger) than
L1 C/A-code.
When compared to the C/A signal, L2CS has 2.7 dB greater data recovery and 0.7 dB greater carrier-tracking, although its transmission power is 2.3 dB weaker.
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6 -24
6.1.8.B
Principals of Operation
CNAV Navigation Message
The CNAV data is an upgraded version of the original NAV navigation message. It contains higher precision representation and nominally more accurate data than the NAV data. The same type of information (Time, Status, Ephemeris, and Almanac) is still transmitted using the new CNAV format; however, instead of using a frame / subframe architecture, it features a new pseudo-packetized format made up of 12-second 300-bit message packets.
In CNAV, two out of every four packets are ephemeris data and at least one of every four packets will include clock data, but the design allows for a wide variety of packets to be transmitted.
With a 32-satellite constellation, and the current requirements of what needs to be sent, less than 75% of the bandwidth is used. Only a small fraction of the available packet types have been defined; this enables the system to grow and incorporate advances.
Important changes in the new CNAV message
CNAV message uses Forward Error Correction (FEC) in a rate 1/2 convolution code, so while the navigation message is 25 bit/s, a 50 bit/s signal is transmitted.
The GPS week number is now represented as 13 bits, or 8192 weeks, and only repeats every 157.0 years, meaning the next return to zero won't occur until the year 2137. This is longer compared to the L1 NAV message's use of a 10-bit week number, which returns to zero every 19.6 years.
There is a packet that contains a GPS-to-GNSS time offset. This allows for interoperability with other global time-transfer systems, such as Galileo and GLONASS, both of which are supported.
The extra bandwidth enables the inclusion of a packet for differential correction, to be used in a similar manner to SBAS and which can be used to correct the L1 NAV clock data.
Every packet contains an alert flag, to be set if the satellite data can not be trusted. This means users will know within 6 seconds if a satellite is no longer usable. Such rapid notification is important for safety-of-life applications, such as aviation.
Finally, the system is designed to support 63 satellites, compared with 32 in the L1 NAV message.
L2CS Frequency information
An immediate effect of having two civilian frequencies being transmitted is the civilian receivers can now directly measure the ionospheric error in the same way as dual frequency P(Y)-code receivers. However, if a user is utilizing the L2C signal alone, they can expect 65% more position uncertainty than with the L1 signal.
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6 -25
6.1.8.C
6.1.8.D
Principals of Operation
•
•
•
•
•
•
L5
Civilian, safety of life signal planned to be available with first GPS IIF launch (2009). Two
PRN ranging codes are transmitted on L5: the in-phase code (denoted as the I5-code); and the quadrature-phase code (denoted as the Q5-code). Both codes are 10,230 bits long and transmitted at 10.23 MHz (1ms repetition). In addition, the I5 stream is modulated with a 10-bit Neuman-Hofman code that is clocked at 1 kHz and the Q5-code is modulated with a 20-bit Neuman-Hofman code that is also clocked at 1 kHz.
Improves signal structure for enhanced performance
Higher transmitted power than L1/L2 signal (-3 dB, or twice as powerful)
Wider bandwidth provides a 10× processing gain
Longer spreading codes (10× longer than C/A)
Uses the Aeronautical Radio-Navigation Services band
The recently launched GPS IIR-M7 satel lite transmits a demonstration of this signal.
L5 Navigation message
The L5 CNAV data includes SV ephemerides, system time, SV clock behavior data, status messages and time information, etc. The 50 bit/s data is coded in a rate 1/2 convolution coder. The resulting 100 symbols per second (sps) symbol stream is modulo-2 added to the I5-code only; the resultant bit-train is used to modulate the L5 in-phase (I5) carrier.
This combined signal will be called the L5 Data signal. The L5 quadrature-phase (Q5) carrier has no data and will be called the L5 Pilot signal.
L5 Frequency information
Broadcast on the L5 frequency (1176.45 MHz, 10.23 MHz × 115), which is an aeronautical navigation band. The frequency was chosen so that the aviation community can manage interference to L5 more effectively than L2.
L1C
Civilian use signal, broadcast on the L1 frequency (1575.42 MHz), which currently contains the C/A signal used by all current GPS users. The L1C will be available with first
Block III launch, currently scheduled for 2013. The PRN codes are 10,230 bits long and transmitted at 1.023 Mbps. It uses both Pilot and Data carriers like L2C.
•
•
•
•
The modulation technique used is BOC(1,1) for the data signal and TMBOC for the pilot.
The Time Multiplexed Binary Offset Carrier (TMBOC) is BOC(1,1) for all except 4 of 33 cycles, when it switches to BOC(6,1). Of the total L1C signal power, 25% is allocated to the data and 75% to the pilot. Implementation provides C/A code to ensure:
Backward compatibility.
1.5 dB increase in minimum C/A code power to mitigate any noise floor increase.
Data-less signal component pilot carrier improves tracking.
Greater civil interoperability with Galileo L1.
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6 -26
6.1.8.E
Principals of Operation
CNAV-2 Navigation message
The L1C navigation message, called CNAV-2, is 1800 bits (including FEC) and is transmitted at 100 bit/s. It contains 9-bit time information, 600-bit ephemeris, and 274-bit packetized data payload
M Code (Military)
A major component of the modernization process, a new military signal called M-code was designed to further improve the anti-jamming and secure access of the military GPS signals. The M-code is transmitted in the same L1 and L2 frequencies already in use by the previous military code, the P(Y) code. The new signal is shaped to place most of its energy at the edges (away from the existing P(Y) and C/A carriers).
Unlike the P(Y) code, the M-code is designed to be autonomous, meaning that users can calculate their positions using only the M-code signal. P(Y) code receivers must typically first lock onto the C/A code and then transfer to lock onto the P(y)-code.
The M-code is intended to be broadcast from a high-gain directional antenna, in addition to a wide angle (full Earth) antenna. The directional antenna's signal, termed a spot beam , is intended to be aimed at a specific region (i.e. several hundred kilometers in diameter) and increase the local signal strength by 20 dB (10X voltage field strength,
100X power). A side effect of having two antennas is that the GPS satellite will appear to be two GPS satellites occupying the same position to those inside the spot beam.
•
•
•
•
•
•
While the full-Earth M-code signal is available on the Block IIR-M satellites, the spot beam antennas will not be available until the Block III satellites are deployed.
Other M-code characteristics are:
Satellites will transmit two distinct signal s from two antennas: one for whole Earth coverage, one in a spot beam.
Modulation is Binary Offset Carrier (BOC) and occupies 24 MHz of bandwidth
Uses a new MNAV navigational message, which is packetized instead of framed, allowing for flexible data payloads
There are four effective data channels; different data can be sent on each frequency and on each antenna.
Can include FEC and error detection
The spot beam is ~20 dB more powerful than the whole Earth coverage beam Mcode signal at Earth's surface: -158 dBW for whole Earth antenna, -138 dBW for spot beam antennas.
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6 -27
6.1.9
Principals of Operation
The Galileo System
Galileo is the European global navigation satellite system which provides a highly accurate, guaranteed global positioning service under civilian control. It is inter-operable with GPS and GLONASS, the two other global satellite navigation systems.
Fig. 6-28 Galileo Satellite (GIOVE Test SV)
A user can take a position with the same receiver from any of the satellites in any combination. By offering dual frequencies as standard, Galileo delivers real-time positioning accuracy down to the metre range. Galileo guarantees availability of the service under all but the most extreme circumstances and informs users within seconds of a failure of any satellite. This makes it suitable for applications where safety is crucial, such as running trains, guiding cars and landing aircraft.
The first experimental satellite, part of the so-called Galileo System Test Bed (GSTB-V1), was launched in 2003. The objective of this satellite was to characterize the critical technologies, developed under ESA contracts. Two initial test satellites were launched
GIOVE-A, in 2005, and GIOVE-B, in 2008, to validate the basic Galileo space segment.
Four In Orbit Validation (IOV) satellites are scheduled to be launched in the 2010 to 2011 time frame, to complete the validation of the space segment in conjunction with the ground segment. A further 16 satellites are currently funded, which will provide a minimum operational capability. The balance of 14 satellites required to reach Full
Operational Capability (FOC), as of 2010, are not currently funded.
The fully deployed Galileo system will consist of 30 satellites (27 operational + 3 active spares), positioned in three circular Medium Earth Orbit (MEO) planes at 23 222 km altitude above the Earth, and at an inclination of the orbital planes of 56 degrees with reference to the equatorial plane. The Galileo navigation signals provide good coverage even at latitudes up to 75 degrees north, which corresponds to the North Cape, and beyond.
The large number of satellites together with the optimization of the constellation, and the availability of the three active spare satellites, ensures that the loss of one satellite has no discernible effect on the user. The use of BOC (Binary Offset Carrier) Modulation minimizes interference with GPS BPSK.
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6 -28
6.1.9.A
6.1.9.B
Principals of Operation
Ground Element
Two Galileo Control Centers:
•
•
Located in Europe
Combine range of facilities: orbit control, integrity, mission control, satellite control, services products, Precise Time Facilities (PTF)
Fifteen Galileo Up-Link Stations:
•
•
•
Located around the globe
Five Telemetry, Telecommand and Tracking Stations
Nine Mission Up-Link Stations
Thirty Galileo Sensor Stations:
•
•
Located around the globe
Monitor quality of the satellite navigation signal (Signal In Space, SIS) Services
Services
The Galileo system consists of five main services:
OS (Open Service) :
'Free to air' and for use by the mass market; Simple timing and positioning down to ï€
1 meter.
CS (Commercial Service) (Encrypted):
Higher data rate, improved accuracy to the centimeter. Guaranteed service for which service providers charge fees.
SoL (Safety Of Life) :
Open service; For applications where guaranteed accuracy is essential; Integrity messages will warn of errors.
PRS (Public Regulated Service): (Encrypted):
Continuous availability even in time of crisis; Government agencies will be main users.
SAR (Search And Rescue) :
System picks up distress beacon locations; Feasible to send feedback, confirming help is on its way. Based on Cospas-Sarsat system re-broadcasts distress messages.
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6 -29
Principals of Operation
Signal
Centre
Frequency
Nominal
Bandwidth
E5 (E5a + E5b)
1191.795 (E5)
1176.45 (E5a) 1207.14
(E5b)
51.15 (E5)
20.46 (E5a) 20.46
(E5b)
Modulation ALTBOC
Sub-carrier a-I a-Q b-I
Submodulation
Services
No ne
No ne
None
Code Rate
(Mc/s)
Encrypted
F/
NA
V
(O
S)
10.
23
Pil ot
10.
23
I/NAV
(OS/CS/
SoL)
10.23
No No No
Sequence
Length
(primary x secondary)
Symbol rate (sps)
102
30 x
20
50
102
30 x
100
10230 x
4
N/A 250
1575.42
24.552
E1
INTERPLEX/CBOC b-Q A B C
No ne
Pil ot
BOC(15
,2.5)
G/NAV
(PRS)
CBOC(
6,1,1)
I/NAV
(OS/
CS/
SoL)
CBOC(
6,1,1)
Pilot
10.
23
2.5575
No Yes
102
30 x
100
25575 x
1
N/A 100
1.023
No
4092 x
1
250
1.023
No
4092 x
25
N/A
Table 6-3 Galileo Signals
6.1.9.C
GPS Receivers
Signal
•
•
•
The strength of the received GPS signal relies on the following parameters:
•
•
•
•
•
•
Signal strength of satellite
Attenuation in transmitter hardware
Gain of transmission antenna (in direction to the receiver)
Free space loss due to distance of satellite and receiver
Attenuation by the atmosphere (negligible)
Deflection and superposition of the direct signal by reflected indirect signals
(multipath)
Gain of receiver antenna
Attenuation in receiver hardware
Signal tracking technique
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6 -30
Principals of Operation
Noise
The level of noise seen by a GPS receiver consists mainly of thermal noise but also background and inter-modulation noise. Most of the single influences are constant or can be assumed to be constant in the order of measurement accuracy.
SNC
Many GPS receivers indicate signal strengths in manufacturer specific units, which are determined from measurements made on the signals by the signal processing hardware.
The values are the result of integrating the out put of a signal cor relator, that is fed the noisy input signal and a clean local replica of the expected PRN code. The integrated result is a linear indication of the signal-to-noise-ratio, over the bandwidth of the correlated signals.
In any particular receiver, this result can vary due to differences in receiver bandwidth and integration time. Often the result is scaled to be consistent across a product range.
The resultant values are often referred to as SNC (Signal-to-Noise-Counts) and are scaled to match a measurement made over a 1KHz bandwidth. The 1KHz comes from the fact that many of the early receivers integrated for 1 millisecond, resulting in an effective
1KHz bandwidth.
Converting SNC to SNR
Normally SNR (Signal to Noise Ratio) is expressed as a power ratio on a logarithmic scale instead of an amplitude ratio on a linear scale.
•
•
To convert:
• SNC in a 1KHz bandwidth = (sA/nA).
Where sA = Signal Amplitude and nA is the Noise Amplitude.
SNR in a 1KHz bandwidth [in dB] = 20*Log10(SNC) - 3db
Converting to C/N
0
A more technically precise and common measurement of GNSS signal strength is known as C/N
0
(carrier-to-noise density) and is the ratio of received carrier (i.e., signal) power to noise density.
Many receivers have the ability to display or output values in these units however, these values are not measured directly, but are calculated from the directly measured SNC count values, refer to table 6-4.
NOTE:
C/N
0
is not the same as SNR (signal-to-noise ratio), although the terms are sometimes used interchangeably. Effectively, C/N
0
assumes that the noise has infinite bandwidth
(and thus power) and therefore characterizes it using a density, that is, as the amount of noise power per unit of bandwidth.
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6 -31
Principals of Operation
•
•
•
•
C/N
0
= the SNR (usually in dB) in a 1Hz bandwidth. That bandwidth is typically 1000 times less than the actual receiver bandwidth, which implies a 30db change in dB-power units:
C/N
0
= SNR[dB]@1KHz + 30db
Therefore. C/N
0
= 30 + 10*Log10(SNC^2/2)
= 30 + 10*Log10(SNC^2) – 3
= 27 + 20*Log10(SNC)
20
30
40
SNC SNR (dB - 1KHz)
3 6.5
C/N
0
(dB - 1Hz)
36.5 ï€
(very weak signal)
5
10
11
7
41
47
23
26.5
53
56.5
29 59 ï€
(very strong signal)
Table 6-4 SNC, SNR and C/N
0
C/N
0
provides a metric that is more useful for comparing one GPS receiver to another than SNR because the bandwidth of the receivers is eliminated in the comparison.
Higher C/N
0
results in reduced data bit error rate (when extracting the navigation data from the GPS signals) and reduced carrier an d code tracking loop jitter. Reduced carrier and code tracking loop jitter, in turn, results in less noisy range measurements and thus more precise positioning.
Determining Noise Figure
Generally, the GPS decoding chipset on a receiver determines the minimum C/N
0
ratio, required to achieve a position fix. However, it is the noise figure of the entire receiver that determines the C/N
0
ratio that you can achieve at a given power level. When measuring sensitivity it is important to know the minimum C/N
0
ratio required to achieve a position fix.
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6 -32
Principals of Operation
Refer to table 6-5. Assuming a constant satellite power, you can observe that the ï€
C/N
0
ratio reported by the receiver is a function of the noise figure of the receiver.
Noise
Figure
1 dB
2 dB
3 dB
4 dB
RF Power
Level
-143 dBm
-143 dBm
-143 dBm
-143 dBm
C/N
0
31 dB -Hz
30 dB -Hz
29 dB -Hz
28 dB -Hz
5 dB -143 dBm 27 dB -Hz
6 dB -143 dBm 26 dB -Hz
Table 6-5 C/N
0
as a Function of Noise Figure
The noise figure of a receiver is directly proportional to the RF power level and C/N
0 ratio. Based on this relationship, you can measure the receivers noise figure by applying the following formula. N figure = -174dBm/Hz + SVpower + C/N
0
For example: -174.0 dBm + -136.1 dBm + 30.0 dB-Hz = 7.9 dB.
Rounding C/N
0
Receivers that support the NMEA-183 protocol, report satellite C/N
0 to the nearest decimal digit, therefore estimating noise figure beyond one digit of precision requires you to investigate the C/N
0
rounding of the receiver.
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6 -33
Principals of Operation
Table 6-6 example results show that RF power levels between -136.6 and -135.7 dBm all produce the same C/N
0
ratio of 30 dB-Hz. Based on the rounding principles involved when reporting NMEA-183 data, it is safe to assume that a power level of -136.1 dBm produces a C/N
0
ratio of 30.0 dB-Hz.
RF Power
Level
-135.6 dBm
-135.7 dBm
-135.8 dBm
-135.9 dBm
-136.0 dBm
-136.1 dBm
-136.2 dBm
-136.3 dBm
-136.4 dBm
-136.5 dBm
-136.6 dBm
-136.7 dBm
Receiver C/N
31 dB -Hz
31 dB -Hz
30 dB -Hz
30 dB -Hz
30 dB -Hz
30 dB -Hz
30 dB -Hz
30 dB -Hz
30 dB -Hz
30 dB -Hz
30 dB -Hz
30 dB -Hz
0
-136.8 dBm
-136.9 dBm
29 dB -Hz
29 dB -Hz
-137.0 dBm
-137.1 dBm
29 dB -Hz
29 dB -Hz
Table 6-6 Correlation of RF Power Level and Receiver C/N
0
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6 -34
Chapter 7 - Product Specifications
7.1
GENERATOR
RF Output Level Direct: - -93 to -155 dBm in 1 dB steps.
± 2 dB accuracy into 50 Ω
DC Isolation: 50V DC
RF Output Level
Ant Coupler: -
Signal Quality:
-68 dBm to -130 dBm in 1 dB steps,
± 2 dB accuracy into 50 Ω
Spurious: <-35 dBc over the bandwidth (40 MHz)
Harmonics: -<-45dBc
External Modulation
Input:
TTL
Carriers:
GPS Carriers:
Galileo Carriers:
Accuracy:
Inter Channel Bias:
Channels:
Single (GPS and Galileo channels may be mixed)
L1: 1575.420 MHz (C/A, pseudo P(Y), SBAS)
L1C: 1575.420
L2:
MHz
1227.600 MHz (pseudo P(Y)
L2C: 1227.600
L5: 1176.450 MHz (New Civil SOL)
E1/L1: 1575.420 MHz (PRS, OS, CS, SOL) (pseudo-G/NAVL)
E5a: 1191.795 MHz (OS, F/NAV)
E5b: 1207.140 MHz (OS,CS,SOL,I/NAV)
Same as Master Oscillator
Zero (Digital Design)
1-6, 1-12 SV simulation, selectable
GPS: PRN=1 to 32.
Galileo: PRN=1 to 30.
SBAS: PRN=120 to138.
User Defined Doppler
Error:
Amplitude Offset:
Step Error:
Satellite Health:
Selectable frequency offset ± 5.0 kHz 1Hz increment
Sets SV carrier amplitude offset from nominal +/-15dB in .1dB increments.
Sets SV psuedo range error +/- 10km in .1m increments or
32,808.4 ft in .1ft increments (used for RAIM testing)
Allows selection of GOOD or BAD (carried in GPS Nav Data)
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7 - 1
Principals of Operation
GENERATOR (cont)
Gal Integrity: Allows selection of CONNECTED or DISCONNECTED.
(Carried in Galileo Nav Data
*
)
Code Carrier Coherence: Sets frequency variation between code carriers
Range 2m/S or 6.562 ft/S
Increment 1mm/S or 001 ft/S
L1 C/A code: Code Rate: 1.023 Mc/s
Primary Code Length: 1023 bits
Modulation: BPSK
Symbol Rate: 50 sps
SBAS Codes: WAAS/EGNOS L1/L5
L1C Code:
L2C Code:
Code Rate: 1.023 Mc/s
Primary Code length: 10,230 bits
Modulation: BPSK
L1 P(Y) pseudo code: Code Rate: 10.230 Mc/s
Primary Code Length: 15,345,000 bits
Modulation: BPSK
NOTE: Long random codes simulated
CM Code Rate: 511.500 b/s
Primary Code length: 10,230 bits
CL Code Rate: 511.500 b/s
NOTE: Long random codes simulated
Primary Code length: 767,250 bits
Modulation: QPSK
L5 Code:
Galileo Codes
Code Rate: 10.230 Mc/s
Primary Code length: 10,230 bits
Modulation: QPSK
From Open Service SIS ICD, Draft 1, European Space Agency/
European GNSS Supervisory Authority
Signal
Centre Frequency
Nominal Bandwidth
Modulation
Sub-carrier
Sub-modulation
Services
Code Rate
(Mc/s)
Encrypted
Sequence Length
(primary x secondary)
Symbol rate (sps)
10.23
No
10230 x 20
50
E5 (E5a + E5b)
1191.795 (E5)
1176.45 (E5a)
51.15 (E5)
20.46 (E5a)
ALTBOC a-I a-Q
None None
F/NAV
(OS)
Pilot
10.23
No
10230 x 100
N/A
E1
1575.42
1207.14 (E5b) b-I
None
I/NAV
(OS/CS/SoL)
10.23
No
10230 x 4
250
20.46 (E5b) b-Q
None
Pilot
10.23
No
10230 x 100
N/A
24.552
INTERPLEX/CBOC
A B
BOC(15,2.5) CBOC(6,1,1)
G/NAV
(PRS)
I/NAV
(OS/CS/SoL)
2.5575
Yes
25575 x 1
100
1.023
No
4092 x 1
250
C
CBOC(6,1,1)
Pilot
1.023
No
4092 x 25
N/A
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7 - 2
7.2
7.3
Principals of Operation
GENERATOR (cont)
NA V Dat a: Navigation Data is computed in real-time to match the simulation
Positional Simulation: Maximum Relative Velocity (Range Rate) ± 1000 kts
Maximum Relative Jerk ± 500 m/s3
Maximum Altitude 100,000 ft
Positional Simulation
Accuracy: Pseudorange <2mm (RMS)
Pseudorange Rate <1mm/s (RMS) with respect to master oscillator
Pseudorange Jerk ±0.02 m/s3 (RMS over >1s)
Delta Pseudorange <2mm (RMS)
Interchannel Code Phase Alignment ± 0.02 m (RSS)
Interchannel Carrier Phase Alignment ± 0.265mm (RSS)
MASTER OSCILLATOR
Frequency: 10 MHz nominal (* see note)
Temperature Stability: ± ppm
Aging Rate: ±0.3 ppm/yr, ± 2.5 ppm/ 10 yr
Uncertainty: ±1 ppm
External Reference Input
Input Level: 0.25 to 6.0 Vp-p
Input Impedance :50 ohm nominal
Input Frequency: 10.0 MHz ±10 Hz
External Reference Output
Output Level: 1.5 Vp-p nominal into 50 Ω
Output Frequency: 10.0 MHz nominal
Reliability
MTBF: >10000
MTTR: 1hr
COUPLER
Type:
Coupling:
Isolation:
Patch in RF Absorbent Foam
-21.5 dB typical at 1575.420 MHz.
> 25 dB at 1575.42 MHz
> 30 dB typical at 1575.42 MHz
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7 - 3
7.4
7.5
7.6
7.7
Principals of Operation
BATTERY
Type: Lithium Ion, Removable Pack
Voltage:
Capacity:
Duration:
14.4 VDC
6.75 AH
4 hrs
Battery charging temperature range: 0° to 45°C.
Note:
DC INPUT
Input Voltage Range: 11 to 32 VDC
Maximum Input Power: 75 W
Maximum Current Input: 5 A
PHYSICAL CHARACTERISTICS
Height:
Width:
Depth:
10.63 inches (27.0 cm)
13.97 inches (35.5 cm)
3.425 inches (8.7 cm)
Weight (Test set only): 15.5 lbs. (7 kg)
ENVIRONMENTAL
Test Set Certifications
Operational Temperature:
Storage Temperature: -
Operational Humidity:
Storage Humidity:
Altitude:
Vibration Limits :
Shock, Function:
Transit Drop:
-20° to 55° C
-51° to 71° C when no battery is installed
MIL-PRF-28800F Class 2
MIL-PRF-28800F Class 2
4600 meters Class 1
MIL-PRF-28800F Class 2
MIL-PRF-28800F Class 2
MIL-PRF-28800F Class 2
Drip Proof:
Dust:
Salt Fog:
Explosive Atmosphere:
MIL-PRF-28800F Class 2
MIL-PRF-28800F Class 1
MIL-PRF-28800F Class 1
MIL-PRF-28800F Class 1
EMI/EMC: MIL-PRF-28800F and EN-61010-1
Safety Compliance: UL-61010-1
EN-61010-1
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7 - 4
7.8
Principals of Operation
ENV IRONMENTAL (cont)
EMC
Emissions:
Immunity:
MIL-PRF28800F Class 2
EN 61326:1998 Class A
EN 61000-3-2
EN 61000-3-3
MIL-PRF28800F Class 2
EN 61326:1998Class A
External AC-DC Converter Certifications
Safety Compliance: UL
CSA 22.2 No. 234
VDE EN 60 950
EMI/RFI Compliance:
EMC:
FCC Docket 20780 Curve "B"
EN 61326
External AC to DC Converter
Use: Indoors
Altitude:
Operating Temperature:
Storage Temperature:
Transit Case Certifications
Drop Test:
< 10,000 m
0° to 40° C
-20° to 71° C
FED-STD-101C Method 5007.1 Paragraph 6.3,
Procedure A, Level A
Falling Dart Impact: I
Vibration, Loose Cargo:
Vibration, Sweep:
Simulated Rainfall:
FED-STD-101C:
FED-STD-101C Method 5019
ATA 300 Category I
MIL-STD-810F Method 506.4 Procedure II of 4.1.2
Method 5009.1 Sec 6.7.1
MIL-STD-810F Method 512.4
Immersion:
ACCESSORIES
RF Coax Cable x 1: Low Loss Coax 50 ft loss calibrated
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7 - 5
Principals of Operation
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7 - 6
Appendix A
Pin-Out Tables
ETHERNET CONNECTOR
Pin Number
1
2
3
6
7
4
5
8
Fig. A-1 Ethernet Pin-Out Diagram
Signal Type
Data
Data
Data
NC
NC
Data
NC
NC
Signal Type
Transmit +
Transmit -
Receive +
NC
NC
Receive -
NC
NC
Function
Ethernet TX +
Ethernet TX -
Ethernet RX +
Ethernet RX -
USB HOST 1 CONNECTOR
Pin Number
1
2
3
4
Fig. A-2 USB Host 1 Pin-Out Diagram
Signal Type
Power
Data
Data
GND
Signal Type
VCC
Data -
Data +
GND
Function
USB Power
USB Data -
USB Data +
Ground
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A - 1
USB HOST 2 CONNECTOR
Pin Number
1
2
3
4
Fig. A-3 USB Host 2 Pin-Out Diagram
Signal Type
Power
Data
Data
GND
Signal Type
VCC
Data -
Data +
GND
Function
USB Power
USB Data -
USB Data +
Ground
USB OTG CONNECTOR
Pin Number
1
2
3
4
5
Fig. A-4 USB OTG Pin-Out Diagram
Signal Type
Power
Data
Data
Control
GND
Signal Type
VCC
Data -
Data +
ID
GND
Function
USB Power
USB Data -
USB Data +
Identify
Ground
DC POWER CONNECTOR
Pin Number
Inner
Outer
Fig. A-5 DC Power Connector Pin-Out Diagram
Signal Type
Power
GND
Signal Type
VCC
GND
Function
HHCP Power
Ground
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A - 2
AUX CONNECTOR
Pin Number
1
2
3
4
5
8
9
6
7
22
23
24
25
18
19
20
21
14
15
16
17
10
11
12
13
26
Fig. A-6 AUX Connector Pin-Out Diagram
Signal Type
DATA
Signal Type
ARINC 429 in A
Function
ARINC 429
Channel 1 RX A
ARINC 429
Channel 1 RX B
DATA
NC
DATA
DATA
ARINC 429 in B
NC
ARINC 429 Out A
ARINC 429 Out B
ARINC 429
Channel 1 TX A
ARINC 429
Channel 1 TX B
NC
Control
NC
RS232 CTS
DATA
Control
DATA
NC
NC
NC
NC
NC
NC
Ext Trigger Output
NC
Ext Trigger Input
NC
NC
NC
NC
NC
DATA
GND
RS232 TX
RS232 RTS
RS232 RX
NC
NC
NC
1
NC
NC
NC
3.3V LVTTL
NC
3.3V LVTTL
NC
NC
NC
NC
NC
1 PPS Sync
2
GND
1
RS 232 Clear to
Send
RS 232 Transmit
RS 232 Ready to
Send
RS 232 Receive
Trigger Out
Trigger In
One Pulse Per
Second
Ground
NOTE 1: RS 232 Settings - Baud Rate 4800, 8 Data Bits, No Parity, 1 Stop Bit.
NOTE 2: Accuracy of 1 PPS signal in relationship to the RF output is typically +/- 30 ns.
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A - 3
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A - 4
Appendix B
Terminology
Term
Anti-Spoofing (AS)
Availability
BIAS
Description
Is a policy of the U.S. Department of Defense by which the P-Code is encrypted (by the additional modulation of a so-called W-Code to generate a new "Y-Code"), to protect the militarily important P-Code signals from being
"spoofed" through the transmission of false GPS signals by an adversary during times of war. Hence civilian GPS receivers are unable to make direct P-
Code pseudo-range measurements and must use proprietary (indirect) signal tracking techniques to make measurements on the L2 carrier wave (for both pseudo-range and carrier phase). All dual-frequency instrumentation must therefore overcome AS using these special signal tracking and measurement techniques.
The number of hours per day that a particular location has sufficient satellites
(above the specified elevation angle, and perhaps less than some specified
PDOP value) to make a GPS position determination possible.
All GPS measurements are affected by biases and errors. Their combined magnitudes will affect the accuracy of the positioning results (they will bias the position or baseline solution). Biases may be defined as being those systematic errors that cause the true measurements to be different from observed measurements by a "constant, predictable or systematic amount", such as, for example, all distances being measured too short, or too long.
Biases must somehow be accounted for in the measurement model used for data processing if high accuracy is sought. There are several sources of biases with varying characteristics, such as magnitude, periodicity, satellite or receiver dependency, etc. Biases may have physical bases, such as the atmosphere effects on signal propagation or ambiguities in the carrier phase measurements, but may also enter at the data processing stage through imperfect knowledge of constants, for example any "fixed" parameters such as the satellite ephemeris information, station coordinates, velocity of light, antenna height errors, etc. Random errors will not bias a solution. However, outlier measurements, or measurements significantly affected by multipath disturbance (which may be considered a transient, unmodelled bias), will bias a solution if the proportion of affected measurements is relatively high compared to the number of unaffected measurements. For this reason, long period static GPS Surveying is more accurate (less likely to be biased) than
"rapid static surveying" or kinematic (single-epoch) positioning.
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B - 1
Binary Shift-Key (BSK)
Modulation
BSK is a modulation technique by which a binary message, such the
Navigation Message or the PRN codes (consisting of 0's and 1's), is imprinted on the carrier wave. Unlike Amplitude Modulation (AM) and Frequency
Modulation (FM), BSK Modulation does not alter the signal level (the
"amplitude") or the carrier wavelength (the "frequency"). At a change in value of the message from 0 or 1, or from 1 to 0, the carrier wave is reversed (the phase is "flipped" by 180°). All reversals take place at the zero-crossings of the carrier (sine) wave (i.e., where the phase is zero).
C/A Code
Carrier
Carrier Phase
Carrier Aided Tracking
Clock Bias
Chip
Term
Channel
Code Phase
Constellation
Control Segment
Description
The standard (Clear/Acquisition) GPS PRN code, also known as the Civilian
Code or S-Code. A spread spectrum direct sequence code only modulated on the L1 carrier, used by the GPS receiver to acquire and decode the L1 satellite signal, and from which the L1 pseudo-range measurement is made.
A radio wave having at least one characteristic (e.g., frequency, amplitude, phase) that can be varied from a known reference value by modulation. In the case of GPS there are two transmitted carrier waves: (a) L1 at 1575.42MHz, (b)
L2 at 1227.60MHz, modulated by the Navigation Message (both L1 and L2), the
P-Code (both L1 and L2) and the C/A-Code (L1).
GPS measurements made on the L1 or L2 carrier signal. May refer to the fractional part of the L1 or L2 carrier wavelength (approximately 19cm for L1,
24cm for L2), expressed in units of metres, cycles, fraction of a wavelength or angle. (One cycle of L1 is equivalent to one wavelength, and similarly for L2.) In carrier phase-based positioning, such as employed in GPS Surveying techniques, carrier phase may also refer to the accumulated or integrated measurement which consists of the fractional part plus the whole number of wavelengths (or cycles) since signal lock-on.
A signal processing strategy that uses the GPS carrier signal to achieve an exact lock-on the PRN code. More efficient and accurate than the standard approach.
The difference between the receiver or satellite clock's indicated time and a well-defined time scale reference such as UTC (Coordinated Universal Time),
TAI (International Atomic Time) or GPST (GPS Time).
One bit of a spreading sequence.
A single satellites signal on a single frequency.
GPS measurements based on the C/A-Code. The term is sometimes restricted to the C/A- or P-Code pseudo-range measurement when expressed in units of cycles.
Refers to either the specific set of satellites used in calculating a position, or all the satellites visible to a GPS receiver at one time, or the entire ensemble of
GPS satellites comprising the Space Segment.
A world-wide network of GPS monitoring and upload telemetry stations operated by, or on behalf of, the US Department of Defense. The tracking data is used by the Master Control Station at Colorado Springs to calculate the satellites' positions (or "broadcast ephemerides") and their clock biases. These are formatted into the Navigation Message which is uploaded on a daily
(perhaps more frequently) basis by the Control Segment stations.
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B - 2
Correlator The GPS receiver "software" or electronic means, implemented in some fashion
(either analogue or digital) within a Tracking Channel, used to shift or compare the incoming signal with an internally generated signal. This operation is performed on the PRN codes, but may be used for more "exotic" mixed signals in the case of L2 measurements, where under the policy of Anti-Spoofing (AS) the L2 PRN code is not known. Correlator design may be influenced such that it is optimized for accuracy, mitigation of multipath, acquisition of signal under foliage, etc.
Term
Cut Off Angle
Data Message
Description
The minimum acceptable satellite elevation angle (above the horizon) to avoid blockage of line-of-sight, multipath errors or too high Tropospheric or Ionospheric
Delay values. May be preset in the receiver, or applied during data postprocessing. For navigation receivers may be set as low as 5°, while for GPS
Surveying typically a cutoff angle of 15° is used.
Also known as the Navigation Message. A 1500 bit message modulated on the L1 and L2 GPS signal, which contains the satellite's location (or ephemeris), clock
(bias) correction parameters, constellation almanac information and satellite health.
Differential GPS (DGPS) A technique to improve GPS accuracy that uses pseudo-range errors measured at a known Base Station location to improve the measurements made by other
GPS receivers within the same general geographic area. It may be implemented in real-time through the provision of a communication link between the GPS receivers, transmitting the correction information in the industry-standard RTCM format, or various proprietary formats. May be implemented in single Base Station mode, in the so-called Local Area DGPS (LADGPS), or using a network of Base
Stations, as in the Wide Area DGPS (WADGPS) implementation.
Dilution of Precision
(DOP)
Dithering
Doppler Shift
An indicator of satellite geometry for a unique constellation of satellites used to determine a position. Positions tagged with a higher DOP value generally constitute poorer measurement results than those tagged with lower DOP. There are a variety of DOP indicators, such as GDOP (Geometric DOP), PDOP (Position
DOP), HDOP (Horizontal DOP), VDOP (Vertical DOP), etc.
The introduction of digital noise into the system. "Clock dithering" is the process by which the U.S. Department of Defense (DoD) degrades the accuracy of the
Standard Positioning Service (i.e. absolute positioning of a C/A-Code capable receiver). "Clock dithering" is the additional satellite clock "bias" induced by the
DoD's "Selective Availability" policy that cannot be corrected for by the broadcast
Navigation Message clock correction parameters.
The apparent change in the frequency of a signal caused by the relative motion of the transmitter and receiver.
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B - 3
Dual Frequency Refers to the instrumentation that can make measurements on both L-Band frequencies, or to the measurements themselves (e.g., L1 and L2 pseudo-range or carrier phase measurements). Dual-frequency measurements are useful for high precision (pseudo-range-based) navigation because the Ionospheric Delay bias can be determined, and the data corrected for it. In the case of Double-
Differenced carrier phase, dual-frequency observations can account for the residual ionospheric bias (for case of long baselines), or aid Ambiguity Resolution for "rapid static" or "kinematic" baseline determination. All "top-of-the-line" GPS receivers are of the dual-frequency variety, and are comparatively expensive because of the special signal processing techniques that must be implemented to make measurements on the L2 carrier under the policy of Anti-Spoofing.
Enhanced Keplerian
Elements (ephemeris)
Those elements which describe the position of a satellite in a different orbit and which comprise the standard Keplerian elements (q.v) and harmonic correction terms for the argument of latitude, orbit radius and inclination angle.
Term
Ephemeris (plural:
Ephemerides)
Fix
Geometric Dilution of
Precision (GDOP)
Description
The file of values from which a satellite's position and velocity (the so-called
"satellite state vector") at any instant in time can be obtained. The "Broadcast
Ephemeris (or Ephemerides)" for a satellite are the predictions of the current satellite position and velocity determined by the Master Control Station, uploaded by the Control Segment to the GPS satellites, and transmitted to the user receiver in the Data Message. "Precise Ephemeris (or Ephemerides)" are post-processed values derived by, for example, the International GPS Service (IGS), and available to users post-mission via the Internet.
A single position with latitude, longitude (or grid position), altitude (or height), time, and date.
An indicator of the geometrical strength of a GPS constellation used for a position/ time solution.
Global Navigation
Satellite System (GNSS)
This is an umbrella term used to describe a generic satellite-based navigation/ positioning system. It was coined by international agencies such as the International
Civil Aviation Organization (ICAO) to refer to both GPS and GLONASS, as well as any augmentations to these systems, and to any future civilian developed satellite system. For example, the Europeans refer to GNSS-1 as being the combination of
GPS and GLONASS, but GNSS-2 is the blueprint for an entirely new system
Global Orbiting
Navigation Satellite
System (GLONASS)
Global Positioning
System (GPS)
This is the Russian counterpart to GPS. It consists of a constellation of 24 satellites
(though the number may vary due to difficulties in funding for the system) transmitting on a variety of frequencies in the ranges from 1597-1617MHz and
1240-1260MHz (each satellite transmits on two different L1 and L2 frequencies).
GLONASS provides worldwide coverage, however, its accuracy performance is optimized for northern latitudes, where it is better than GPS's SPS (there being no
"Selective Availability" on GLONASS satellites). GLONASS positions are referred to a different Datum to those of GPS, i.e. PZ90 rather than WGS84.
A system for providing precise location which is based on data transmitted from a constellation of 24 satellites. It comprises three segments: (a) the Control Segment,
(b) the Space Segment, and (c) the User Segment.
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B - 4
GPS Time (GPST)
Height (Orthometric)
GPST is a form of Atomic Time, as is, for example, Coordinated Universal Time
(UTC). GPST is "steered" over the long run to keep within one microsecond of UTC.
The major difference is that while "leap seconds" are inserted into the UTC time scale every 18 months or so to keep UTC approximately synchronised with the earth's rotational period (with respect to the sun), GPST has no leap seconds. At the integer second level, GPST matched UTC in 1980, but because of the leap seconds inserted since then, GPST is now (end 1998) ahead of UTC by 12 seconds (plus a fraction of a microsecond that varies from day to day). The relationship between
GPST and UTC is transmitted within the Navigation Message.
The Orthometric Height is the height of a station on the earth's surface, measured along the local plumbline direction through that station, above the Geoid surface. It is approximated by the "Height Above Mean Sea Level", where the MSL Datum is assumed to be defined by the mean tide gauge observations over several years.
The relationship between Orthometric Height (H) and Ellipsoidal Height (h) is : h = H
+ N, where N is the Geoid Height or Geoid Undulation with respect to the Reference
Ellipsoid. Orthometric Height is traditionally derived from geodetic levelling (using such techniques as optical levelling, trigonometrical levelling, barometric levelling).
Term
Inter-Channel Bias
Inter-Frequency Bias
Inter-Sub-carrier Bias
Description
The difference in the code (or carrier) phases between two simultaneously simulated signals from the same satellite on different frequencies, excluding any effects from the propagation path or deliberately introduced errors, and after applying any corrections that are broadcast in the navigation message.
The difference in the code (or carrier) phases between two simultaneously simulated signals from the same satellite on different frequencies, excluding any effects from the propagation path or deliberately introduced errors, and after applying any corrections that are broadcast in the navigation message.
The difference in the code (or carrier) phases between any two sub-carriers (e.g. I and
Q) of the same signal.
Ionosphere, Ionospheric
Delay
The Ionosphere is that band of atmosphere extending from about 50 to 1000 kilometres above the earth's surface in which the sun's ultraviolet radiation ionizes gas molecules which then lose an electron. These free electrons influence the propagation of microwave signals (speed, direction and polarization) as they pass through the layer.
The Ionospheric Delay on GPS signals is frequency-dependent and hence impacts on the L1 and L2 signals by a different amount (unlike that within the Troposphere). A linear combination of pseudo-range or carrier phase observations on the L1 and L2 carrier waves can be created to almost entirely eliminate the Ionospheric Delay. The resulting observable is known as the Ionosphere-Free carrier phase (or pseudo-range).
For single-frequency receivers it is not possible to account for this signal bias in this way. A broadcast model is contained within the transmitted Navigation Message, however, it is a relatively poor model (unlikely to account for more than 50% of the effect) as the Delay is very difficult to predict. The magnitude of the Ionospheric Delay is a function of the latitude of the receiver, the season, the time of day, and the level of solar activity. The Delay in the Zenith direction can be several tens of metres, increasing as the elevation angle of the satellite signal reduces (being 3-5 times greater than in the Zenith direction). The Delay is largely eliminated in Relative or Differential
Positioning, however, the residual Ionospheric Delay increases as the baseline length increases and may be a significant source of error (especially in the height component) for very high precision GPS Geodesy. Even when using dual-frequency instrumentation, the Ionospheric Delay can still cause problems during the process of rapid Ambiguity Resolution when phase and range combinations other than the
Ionosphere-Free one are used.
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B - 5
L1 Frequency
1575.42MHz
GPS carrier frequency which contains the C/A-Code, the encrypted P-Code (or Y-
Code) and the Navigation Message. Commercial GPS navigation receivers can track only the L1 carrier to make pseudo-range (and sometime carrier phase and Doppler frequency) measurements.
Rice Factor
Satellite (or User)
Location (or Trajectory)
Standard Keplerian
Elements (almanac)
The ratio between the power of the direct component and the mean power of the
Rayleigh faded component in Rician fading, expressed in dB. A Rice factor of + ∞ dB implies no fading, while ∞ dB implies Rayleigh fading.
The location (or trajectory) of the center of gravity of the satellite (or user).
Sub-carrier
Those elements which describe the position of a satellite in a perfectly elliptical orbit and which comprise semi-major axis, eccentricity, inclination angle, longitude (or right acention) of the ascending node (or at epoch), argument of perigee, and one of mean, true, and eccentric anomaly.
One of the separate modulated streams on a given frequency (either I and Q, or A, B and C).
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B - 6
Appendix C
Exporting, Editing and Importing Waypoints
The purpose of this appendix is to describe a method of adding custom waypoints to the
GPSG-1000 without using the graphical users interface and touchscreen to enter waypoint data. Waypoint data will instead be entered on a PC, and then the custom data will be transferred to the GPSG-1000 using the file/waypoint/import feature.
Waypoints, as stored in the GPSG-1000, are a set of data that describe a point in 3D space, along with data to name/mark that location. Custom waypoints on the GPSG-1000 are stored in a comma separated variable file (CSV) which can be shared among
GPSG-1000 units using the waypoint export and import functions. It is important to note that importing a custom waypoint file from another GPSG-1000 will result in the custom waypoints of the receiving unit to be overwritten. If the files from two different units need to be merged, it must be done external to the unit, and can be accomplished using the editing techniques that I will describe in this document.
Creating Cus tom Waypoints
Only Custom Waypoint data may be exported from the GPSG-1000. Once a Custom
Waypoint is added to the GPSG-1000 it can then be exported to a USB drive and edited.
To create a Custom Waypoint, select Waypoint from the main toolbar located at the left of the screen. The Waypoint screen appears (Figure C-1).
Fig. C-1 Waypoint Screen
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C - 1
Select the Add button, the Waypoint Edit screen appears (Figure C-2).
Fig. C-2 Waypoint Edit Screen
On the Waypoint Edit Screen select one of the lines from the table. For this exercise we will select ANC, line 7. Once you have highlighted the line, select Next. The data from the selected line will now populate the Waypoint Edit Screen (Figure C-3).
Fig. C-3 Waypoint Edit, Waypoint Data Screen
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C - 2
Select the Code field and enter a new code to identify the new Custom Waypoint. In this example we will use EXP1. Press Done, The new Custom Waypoint will be added to the
Waypoint List (Figure C-4).
Fig. C-4 New Waypoint List
Exporting Waypoints
Exporting waypoints is done through the File/Waypoint page, to open the file screen first click on the main menu at the left side of the touchscreen, and select the ‘File’ button. On the file screen open the ‘Waypoint’ tab.
To export the custom waypoints, plug a compatible USB flash drive into one of the two
USB ports located on the side of the box where the glare screen attaches, wait approximately 5 to 10 seconds for the unit to recognize the drive and then press the
‘Export to USB’ button on lower right of the Waypoint page (Figure C-5).
Fig. C-5 File Waypoints Screen
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C - 3
A green popup box will appear and confirm when the export has completed (Figure C-6).
Fig. C-6 Waypoint Export Successful
Editing the C usto mer Waypo int File
Remove the USB flash drive from the GPSG-1000, and place the drive in a PC. The custom waypoint file will be located in the following directory /Aeroflex/Waypoint and will be named userairports.csv.
The Waypoint File may be opened in Excel or a Text type editor like Notepad++.
Excel Type Editor
The Waypoint information may be edited, copied, or new lines added. Ensure that each new Waypoint added has a unique identifying code in column D. Column J is added to the end of each Waypoint entry and set to “0”, forcing a comma at the end of each row of the output file.
A
Ted Stevens Anchorage Intl
B
Anchorage
C D E F G
EXP1 PANC 61.174361
-149.996361
H
152
I
0
J
0
Column A
Column B
Column C
Column D
Column E
Column F
Column G
Column H
Column I
Column J
A unique name the user assigns to each user Waypoint.
City.
Country, not currently used.
Unique code to each user Waypoint. GPSG-1000 can sort Waypoints by this code.
CAO Code. A four-character code designating each airport around the world.
Latitude
Longitude
Altitude (in this case expressed in ft)
UTC offset, not currently used.
This column is added when the Waypoint file is edited to insert a comma at the end of the sentence. 0 should be entered here.
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C - 4
Text Type Editor
The Waypoint information may be edited, copied, or new lines added. The sentence terms are identical to the Excel type editor file, however, the line is already terminated with a comma.
Ted Stevens Anchorage Intl,Anchorage,,EXP1,PANC,61.174360999999998,-149.99636100000001,
151.99999999999997,0,
Note: If Waypoint File contents exceeds a few thousand entries the loading and sorting functions in the GPSG-1000 will be slowed.
When editing is complete, save the file to the USB flash drive in the same directory location and with the same name from which it was originally opened.
Importing Waypoints
Importing waypoints is done through the File/Waypoint page, to open the file screen first click on the main menu at the left side of the touchscreen, and select the ‘File’ button.
On the file screen open the ‘Waypoint’ tab (Figure C-7).
To import the custom waypoints, plug a compatible USB flash drive into one of the two
USB ports located on the side of the box where the glare screen attaches, wait approximately 5 to 10 seconds for the unit to recognize the drive.
Fig. C-7 File Waypoints Screen
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C - 5
Press the Import From USB button on lower left of the Waypoint page. A pop-up box will appear with a warning that importing from the USB will overwrite the existing waypoints on the system. Press Yes to continue (Figure C-8.)
Fig. C-8 USB Import Warning Pop-up
A green popup box will appear and confirm when the import has been completed
(Figure C-9).
Fig. C-9 Waypoint Import Successful
The Waypoint imported to the GPSG-1000 will now be visible in the Waypoint Screen.
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C - 6
Appendix D
Exported and Imported File Formats
The GPSG-1000 has the ability to import and export a number of different file types for different uses. The file types include Almanac, KML, NMEA (Trajectory), Route, Settings and Waypoint. This appendix will attempt to explain the content of each of the file types that are able to be exported and imported onto the unit so the user can understand the content and format of each.
File Locatio ns
Within the GPSG-1000, the various user files are stored on a static memory device, and with the exception of the load, store, manage, delete, import and export functions provided to the user through the UI, the user cannot further manipulate the files while they are contained within the unit. The user can however export the files to a USB drive where they can be accessed, edited and stored, and then using the import function of the
GPST-1000, they can be reloaded onto the unit for use. When the various file types have been loaded onto a USB stick, the directories are created under the /Aeroflex directory which is located at the root of the USB device (Figure D-1).
Fig. D-1 File Locations
Almanac s Files
The Almanacs directory contains almanac files in Yuma format (ICD-GPS-8.70 Rev A,
Date Jun 15, 2011). The Almanacs files are either generated by the GPSG-1000 internal receiver downloads, or are downloaded from the United States Coast Guard repository website.
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D - 1
An example of the Almanac data file:
******** Week 799 almanac for PRN-01 ********
ID: 01
Health: 000
Eccentricity: 0.3730297089E-002
Time of Applicability(s): 61440.0000
Orbital Inclination(rad): 0.9613649345
Rate of Right Ascen(r/s): -0.7863184676E-008
SQRT(A) (m 1/2): 5153.619629
Right Ascen at Week(rad): 0.9558857469E+000
Argument of Perigee(rad): 0.444257464
Mean Anom(rad): -0.1754657556E+001
Af0(s): -0.1144409180E-004
Af1(s/s): 0.0000000000E+000 week: 799
Kml Files
The Kml directory contains files generated from the application GoogleEarth in Kml format on a PC, which have then been imported onto the GPSG-1000. The GPSG-1000 compiles the Kml files into Trajectory data files with a .gdt extension in CSV format.
Kml files are trajectory routes that are intended to follow a course laid out in GoogleEarth at a constant velocity. The files must have certain conditions; the altitude must be expressed in absolute terms, navigation points must be properly positioned for the speed and turning radius of the simulation. Therefore it is generally not suitable to convert recorded routes from a GPS receiver in to Kml files for simulation in the GPSG-1000.
Recorded routes should be loaded to the GPSG-1000 as Nmea Files for playback.
The compiled .gdt files are in the following format:
Notes,Date,Time,Latitude,Longitude,Alt,Desc
$GDT,20000101,000144.00,38.9425699612859,-94.7561817577427,0.000000,3D,*16
$GDT,20000101,000145.00,38.9425695029864,-94.7561783124509,-0.000004,3D,*3F
$GDT,20000101,000146.00,38.9425681280874,-94.7561679765759,-0.000018,3D,*34
$GDT,20000101,000147.00,38.9425658365869,-94.7561507501185,-0.000039,3D,*39
$GDT,20000101,000148.00,38.9425626284821,-94.7561266330799,-0.000069,3D,*37
$GDT,20000101,000149.00,38.9425585037686,-94.7560956254621,-0.000106,3D,*35
$GDT,20000101,000150.00,38.9425534624409,-94.7560577272674,-0.000150,3D,*3E
$GDT,20000101,000151.00,38.9425475044924,-94.7560129384988,-0.000200,3D,*34
$GDT,20000101,000152.00,38.9425406299151,-94.7559612591597,-0.000254,3D,*3F
$GDT,20000101,000153.00,38.9425328387000,-94.7559026892542,-0.000312,3D,*3A
$GDT,20000101,000154.00,38.9425241308367,-94.7558372287867,-0.000371,3D,*34
$GDT,20000101,000155.00,38.9425145063137,-94.7557648777623,-0.000431,3D,*3F
$GDT,20000101,000156.00,38.9425039651181,-94.7556856361865,-0.000489,3D,*30
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D - 2
Nmea Files
The Nmea directory contains files with an NME extension that contain data in NMEA-0183 sentence format. The GPSG-1000 is able to use GGA, RMC and GSV sentences from these files. In general the NMEA-0183 files are created by the internal or an external
GPS receiver.
Nmea file example:
$GPGGA,150923.000,3856.4506,N,09445.2627,W,1,07,1.1,332.2,M,-30.1,M,,0000*68
$GPGSV,3,1,11,29,65,303,50,05,63,046,52,26,36,124,45,02,31,082,49*73
$GPGSV,3,2,11,25,25,230,43,15,24,164,47,21,19,285,40,12,11,198,40*7B
$GPGSV,3,3,11,10,08,049,40,30,06,321,41,18,04,230,36*40
$GPRMC,150923.000,A,3856.4506,N,09445.2627,W,0.09,154.82,290113,,,A*79
The sentence structure for each position sentence:
GGA
Essential fix data which provide 3D location and accuracy data.
$GPGGA,150923.000,3856.4506,N,09445.2627,W,1,07,1.1,332.2,M,-30.1,M,,0000*68
Where:
GGA Global Positioning System Fix Data
150923.000 Fix taken at 12:35:19 UTC
3856.4506,N Latitude
09445.2627,W Longitude
1 Fix quality: 0 = invalid
1 = GPS fix (SPS)
2 = DGPS fix
3 = PPS fix
4 = Real Time Kinematic
07
1.1
332.2,M
-30.1,M
5 = Float RTK
6 = estimated (dead reckoning) (2.3 feature)
7 = Manual input mode
8 = Simulation mode
Number of satellites being tracked
Horizontal dilution of position
Altitude, Meters, above mean sea level
Height of geoid (mean sea level) above WGS84 ellipsoid
(Empty field) Time in seconds since last DGPS update
0000 DGPS station ID number
*68 Checksum data, always begins with *
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D - 3
GSV
Satellites in View shows data about the satellites that the unit might be able to find based on its viewing mask and almanac data.
$GPGSV,3,1,11,29,65,303,50,05,63,046,52,26,36,124,45,02,31,082,49*73
Where:
GSV Satellites in view
3 Number of sentences for full data
1 Sentence 1 of 3
11 Number of satellites in view
29 Satellite PRN number
65 Elevation, degrees
303 Azimuth, degrees
50 SNR - higher is better
Repeat PRN, Elevation, Azimuth and SNR for up to 4 satellites per sentence
*75 Checksum data, always begins with *
RMC
NMEA has its own version of essential gps pvt (position, velocity, time) data. It is called
RMC, The Recommended Minimum, which will look similar to:
$GPRMC,150923.000,A,3856.4506,N,09445.2627,W,0.09,154.82,290113,,,A*79
Where:
RMC Recommended Minimum sentence C
150923.000 Fix taken at 12:35:19 UTC
A Status A=active or V=Void.
3856.4506,N Latitude
09445.2627,W Longitude
0.09 Speed over the ground in knots
154.82 Track angle in degrees True
290113 Date - 23rd of March 1994
(Empty field),, Magnetic Variation
A NMEA 2.3 additional field
*79 Checksum data, always begins with *
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D - 4
Route Files
Route files are used to populate the route table on the Route page (Figure D-2)..
Fig. D-2 Route Page
The files are stored and exported from the GPSG-1000 in XML format. The beginning and end of each route file is designated by the te xt <Route>. The body of the route consists of a number of route points with the following contents. Please note that the route data shown in the example consists of six route points.
<Route>
<Waypoint Longitude="-77.88420000000001" MaxAcceleration="0" MaxClimbRate="0"
Name="HESKU" Latitude="37.14982222222222" Altitude="1524" TargetSpeed="53.64466666666667"
TurningCircleRadius="108.5658611334349"/>
<Waypoint Longitude="-78.80005277777778" MaxAcceleration="0" MaxClimbRate="0"
Name="RFLAT" Latitude="38.20028888888889" Altitude="1524" TargetSpeed="53.64466666666667"
TurningCircleRadius="131.3646919714563"/>
<Waypoint Longitude="-78.83963333333332" MaxAcceleration="9.800000000000001"
MaxClimbRate="-3.048" Name="RIVKE" Latitude="38.24149166666667" Altitude="1249.68"
TargetSpeed="53.64466666666667" TurningCircleRadius="100"/>
<Waypoint Longitude="-78.88314444444444" MaxAcceleration="9.800000000000001"
MaxClimbRate="-3.048" Name="BEEDY" Latitude="38.28670277777778" Altitude="944.88"
TargetSpeed="53.64466666666667" TurningCircleRadius="100"/>
<Waypoint Longitude="-78.95743055" MaxAcceleration="9.800000000000001"
MaxClimbRate="-3.048" Name="RW33" Latitude="38.363725" Altitude="355.092"
TargetSpeed="53.64466666666667" TurningCircleRadius="131.3646919714563"/>
<Waypoint Longitude="-79.13772222222222" MaxAcceleration="9.800000000000001"
MaxClimbRate="3.048" Name="MOL" Latitude="37.86372222222222" Altitude="1828.8"
TargetSpeed="75.99661111111111" TurningCircleRadius="183.4763053155051"/>
</Route>
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D - 5
The Route data variables are formatted as follows:
Waypoint Longitude is followed by the longitude value of the waypoint in
DDD.DDDDDDDD format. Values in the western hemisphere are indicated by negative values, and values in the eastern hemisphere are indicated by positive values.
Max Acceleration is followed by the maximum acceleration value that the body in motion is allowed to achieve in the lateral and longit udinal axes as it travels from the current waypoint to the next. The acceleration value is expressed in m/s
2
.
Max Climb Rate is followed by the maximum climb or descent rate that the body in motion is allowed to achieve as it travels from the current waypoint to the next. The climb/ descent rate is expressed in m/s.
Name is followed by the text indicating the name of the waypoint.
Latitude is followed by the latitude value of the waypoint in DD.DDDDDDDD format.
Values in the southern hemisphere are indicated by negative values, and values in the northern hemisphere are indicated by positive values.
Target Speed is followed by the target speed of the body in motion as it passes through the waypoint. The target speed is expressed in m/s.
Turning Circle Radius is followed by the turning circle radius of the body in motion that defines the commanded path to be followed. The turning circle radius is expressed in meters.
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D - 6
Settings Files
The Settings file directory contains settings files generated from the GPSG-1000 File/
Settings page. The Settings data is in XML format. Following is an example of the
GPSG-1000 Power Up Settings. The Settings File can be edited and imported to other
GPSG-1000 units to set a common start condition. Care must be taken to ensure settings parameters are compatible with the test set.
<!DOCTYPE GpsgPowerupConfig>
<GpsgPowerupConfig>
<SimulationSetup>
<SimulationMode>Gps</SimulationMode>
<Carrier>L1_E1</Carrier>
<SbasMode>Auto</SbasMode>
<SimulationType>Static</SimulationType>
<DigitalNoiseMode>Off</DigitalNoiseMode>
<FadingMode>None</FadingMode>
<PrnSignalType>Fixed</PrnSignalType>
<PositionSource>User</PositionSource>
<ClockSetting>User</ClockSetting>
<UserDateTime>2011-08-05T21:12:16</UserDateTime>
<UnitsType>Imperial</UnitsType>
<LatLonFormat>DD°MM'SS.SS"</LatLonFormat>
<RfPortSelection>Coupler</RfPortSelection>
<RfLevel>-130</RfLevel>
<RouteLooping>0</RouteLooping>
<MotionModel type="Unlimited">
<Pedestrian LateralAcceleration="2.94" Velocity="10.72896"
LongitudinalAcceleration="2.94"/>
<Automobile LateralAcceleration="9.800000000000001"
Velocity="89.408"
LongitudinalAcceleration="9.800000000000001"/>
<Marine LateralAcceleration="6.86" Velocity="44.704"
LongitudinalAcceleration="6.86"/>
<LowPerfAircraft LateralAcceleration="19.6" Velocity="223.52"
LongitudinalAcceleration="9.800000000000001"/>
<HiPerfAircraft LateralAcceleration="88.2" Velocity="447.04"
LongitudinalAcceleration="49"/>
<Custom LateralAcceleration="19.6" Velocity="0.44704"
LongitudinalAcceleration="9.800000000000001"/>
<Unlimited LateralAcceleration="98" Velocity="514.096"
LongitudinalAcceleration="98"/>
</MotionModel>
</SimulationSetup>
<ChannelsSetup Gnss="12" Galileo="5" Gps="6" SingleSbas="0" Sbas="1"/>
<IoSetup>
<LossValues Splitter="0" Coupler="0" DirectCable="0" CouplerCable="0"/>
<ExternalRefOutMode>Off</ExternalRefOutMode>
<ReferenceSource>Internal</ReferenceSource>
<TriggerMode>Auto</TriggerMode>
</IoSetup>
<DefaultStaticPoint Longitude="0" Latitude="0" Altitude="0"/>
<DefaultFiles Trajectory="" Route="Default Route" Almanac=""/>
<DiagnosticsSetup>
<DiagnosticsMode>Off</DiagnosticsMode>
<Frequency>1176.45 MHz</Frequency>
<Amplitude>-100</Amplitude>
<DopplerError>0</DopplerError>
</DiagnosticsSetup>
</GpsgPowerupConfig>
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D - 7
Way point Files
The Waypoint file directory contains user entered custom waypoints created on the waypoint page. The Waypoint data is in CSV format. The Waypoint files will open in
Excel.
A
NY to RM 01
NY to RM 02
Waypoint csv file example:
C B
NA
NA
D
TR01
TR02
E F
NA 49.0875
NA 49.82806
G
-45.3539
-19.7547
H
7000
7000
I
0
0
J
0
0
Where:
Column A
Column B
Column C
Column D
Column E
Column F
Column G
Column H
Column I
Column J
Unique name the user assigns to each user Waypoint.
City. In this case the Waypoint is not in a city.
Country, not currently used.
Unique code to each user Waypoint. GPSG-1000 can sort
Waypoints by this code.
CAO Code. A four-character code designating each airport around the world. In this case the Waypoint is not an airport.
Latitude
Longitude
Altitude (in this case expressed in ft)
UTC offset, not currently used.
This column is added when the Waypoint file is edited to insert a comma at the end of the sentence. 0 should be entered here.
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D - 8
Appendix E
Recording and Playing Trajectory Routes
Trajectory files recorded by GPS receivers or the GPSG-1000 and saved in the .gdt or
.nme format may be played back in the GPSG-1000 for simulation and testing of GPS receivers. This appendix will detail the steps required to record a Trajectory route in the
GPSG-1000 GPS RX and playback the file for simulation.
Files saved from other GPS receivers may have .nmea file extension. When transferred to the GPSG-1000 for playback they must be renamed with .mne file extension. See
Application Note: GPSG-1000 File Properties. Once renamed and transferred to the
GPSG-1000, they may then played in the same manner as files recorded by the GPSG-
1000.
The GPSG-1000 GPS RX will record its position and route. Attach the included GPS RX antenna. From the Main Menu, select the down arrow (Figure E-1).
Fig. E-1 Main Menu
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From the lower portion of the Main Menu, select GPS RX (Figure E-2).
Fig. E-2 Main Menus, Lower Section
The GPS RX page will display the current GPS position fix and the visible satellite
(Figure E3).
Fig. E-3 GPS RX Page
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Wait for the GPS RX to acquire a 3d position fix. (Figure E-4).
Fig. E-4 GPS RX Page with 3d Fix
Press the Record Trajectory button to start recording. The GPSG 1000 will continue to record until the Stop Recording button is pressed. Note the Current Date/Time field, the time is displayed as GMT (Figure E-5 ).
Fig. E-5 GPS RX Page, Recording Trajectory
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The data will be stored in a file with the following naming convention:
MMDDYYYY_HHMMSS.mne.
.
The time recorded for the file name is the time the recording is stopped. To load the new
Trajectory File for playback select File from the Main Menu and then Trajectory from the tabs at the top of the page. Press the Load button and select the new .nme file, press
Open (Figure E-6).
Fig. E-6 File Page, Trajectory File Saved
The new Trajectory file will appear in the Current Trajectory File widow (Figure E-7).
Fig. E-7 File Page, Trajectory Loaded
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To run the Trajectory File simulation, select Setup from the Main Menu. In the GNSS window in the Simulation field select Trajectory. In the PRN Signal field select Traj File.
Set the RF Level in the RF Output window to the desired level (Figure E-8).
The Trajectory File records the Signal to Noise Ratio of the received GPS signal. During playback the GPSG-1000 will adjust the RF Power Level to simulate the actual recorded
S:N. For this feature to work the simulation must be played back with the same Almanac with which the recording was made. If the Trajectory File is played with a different
Almanac the positional simulation will run, but, the Simulation screen will show a “Red” indicator for Traj Power and the RF Level will remain at the set level.
Fig. E-8 Setup Page, Trajectory Setup
Close the Setup page and select Simulation from the Main Menu. Press Run and the
Trajectory Simulation will start (Figure E-9)
Fig. E-9 Simulation Page, Trajectory File Running
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The Simulation will run until the end of the Trajectory File (Figure E-10).
Fig. E-10 Trajectory Simulation Complete
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E - 6
Appendix F
GPSG-1000 USB Memory Device
Format Compatibility
The GPSG-1000 uses USB Memory Devices as a utility to update software and to import and export almanac, route, and other files. Some types of USB Memory Devices have proven to be un-readable by the GPSG-1000 due to incompatible formatting. The GPSG-
1000 requires a USB Memory Device to be formatted as FAT32 or FAT16 only. It is also recommended that users have a dedicated USB Memory Device for the GPSG-1000 so that the directory structure does not get corrupted. The directory file structure is shown in
Figure 1 below. Cobham AvComm recommends USB Memory Device P/N 67325, available for purchase from the Cobham AvComm Customer Help Desk at 800-835-2350 or email [email protected]
.
Fig. F-1 File Locations
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Appendix G
Connecting Dual Antenna Coupler Kit
GPSG Dual Antenna Coupler Kit Connection
1.
2.
3.
4.
STEP PROCEDURE
Connect Coaxial Cable (TNC) (50 ft) (supplied with the GPSG-1000) between the
GPS TX COUPLER Connector and the GPSG Splitter Common Port.
Connect two Coaxial Cables (TNC) (12 ft) between the GPSG Splitter and two
GPSG-1000 Antenna Couplers.
(Use the GPSG-1000 Antenna Coupler and Shot Bag supplied with the GPSG-
1000.)
Ensure the Connector Termination is in place on the open GPSG Splitter connector.
For Coupler Loss and Cable Loss values to enter in the GPSG-1000 I/O Setup
Screen; calculate the average insertion loss of the Couplers to enter as Coupler
Loss. Calculate the average loss of the Coupler Cables in this Kit, add that value to the cable loss value for the Coupler Cable included in the GPSG-1000 Test Set and 9.5 dB for the splitter loss.
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Appendix H
Connecting Triple Antenna Coupler Kit
GPSG Triple Antenna Coupler Kit Connection
1.
2.
3.
STEP PROCEDURE
Connect Coaxial Cable (TNC) (50 ft) (supplied with the GPSG-1000) between the
GPS TX COUPLER Connector and the GPSG Splitter Common Port.
Connect three Coaxial Cables (TNC) (12 ft) between the GPSG Splitter and three
GPSG-1000 Antenna Couplers.
(Use the GPSG-1000 Antenna Coupler and Shot Bag supplied with the GPSG-
1000.)
Enter Coupler Loss and Cable Loss values into in the GPSG-1000 I/O Setup
Screen. Calculate the average insertion loss of the Couplers and enter as
Coupler Loss. Calculate the average loss of the Coupler Cables in this Kit, add that value to the cable loss value for the Coupler Cable included in the GPSG-
1000 Test Set and 9.5 dB for the splitter loss.
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Appendix I
Direct Connecting to GPS Receivers
Requiring Antenna Load Simulators
Using the Aeroflex GPSG-1000 and Optional Kit
Some GPS receivers require a resistive load be present on the antenna port of the receiver for proper operation. If a resistive load is not present, the receiver indicates an antenna fault and the system self-test indicates a failure. The components within this kit provides a resistive load required by some GPS receivers when direct connecting the
GPSG-1000 to the RF input of the receiver. This load prevents some GPS receivers from failing their internal self-tests. The Bias-Tee and RF terminator provided within this kit simulates a 26 mA load in a 5 Vdc system. Other load values may be required depending on the needs of the individual GPS receiver under test. The content of this kit is not required if using the GPSG-1000 RF coupler to transmit GPS data to the antenna of the
GPS receiver under test.
GPSG Dual Antenna Coupler Kit Connection
1.
2.
3.
4.
STEP PROCEDURE
Connect the RF terminator (P/N 113102) to Port C (DC IN) of the Bias-Tee (P/N
113101).
Connect the TNC to SMA coaxial cable (P/N 113103) from Port B (DC OUT) of the
Bias-Tee (P/N 113101) to the GPS antenna input connector of the receiver under test.
Connect the GPSG-1000 to Port A (DC BLOCK) of the Bias-Tee (P/N 113101) using the TNC to TNC coaxial cable (supplied with the GPSG-1000).
Add the loss factor of the TNC coaxial cable supplied with the GPSG-1000 with
0.3 dB (typical) for the Bias Tee loss and 0.95 (typical) for the Coax Assy (P/N
113103). Enter this value into the Direct Connect cable loss in the GPSG-1000
Setup I/O Window. If the supplied cables are not used, the cables used should be characterized and the values entered.
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5.
Using the GPSG-1000 User’s Manual as a reference, set up and begin a GNSS simulation on the GPSG-1000.
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A
Appendix A
Pin-Out Tables
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1
Appendix B
Terminology
. . . . . . . . . . . . . . . . . . . . . . . .
C
Controld and Connectors
Front Panel
. . . . . . . . . . . . . . . . . . . . . . . . 2-4
Rear Panel
. . . . . . . . . . . . . . . . . . . . . . . . . 2-6
D
Defining Parameters
Data Slew Bar
. . . . . . . . . . . . . . . . . . . . . 2-12
Drop-down Menus
. . . . . . . . . . . . . . . . . . 2-12
Entering Numeric Values
. . . . . . . . . . . . . 2-11
Numeric Keypad
. . . . . . . . . . . . . . . . . . . . 2-11
Selectaqble Units
. . . . . . . . . . . . . . . . . . 2-12
Description
. . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Nomenclature Cross-Reference
Scope
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
E
Equipment Capabilities and Features
Capabilities
. . . . . . . . . . . . . . . . . . . . . . . . 1-2
Features
Utilities
. . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
. . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
F
File and Data Management
,
File Trajectory Function Window
Functions
. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
I
Installation
. . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
Bench Top
. . . . . . . . . . . . . . . . . . . . . . . . . 2-3
Ventilation Requirements
M
Maintenance
External Cleaning
Almanac Update
Visual Inspections
. . . . . . . . . . . . . . . . . . . 5-1
Introduction
. . . . . . . . . . . . . . . . . . . . . . . . 5-1
Maintenance Procedures
. . . . . . . . . . . . . . 5-1
. . . . . . . . . . . . . . . . . . . 5-6
. . . . . . . . . . . . . . . . . . . 5-1
Maintenance Procedures
Battery Replacement
. . . . . . . . . . . . . . . . . 5-1
Operating Procedures
Power Off Test Set
Power On Test Set
O
. . . . . . . . . . . . . . . . . . 2-7
. . . . . . . . . . . . . . . . . . 2-7
. . . . . . . . . . . . . . . . . . 2-7
Index
P
Power Requirements
Battery Recharging
. . . . . . . . . . . . . . . . . . . 2-1
. . . . . . . . . . . . . . . . . . 2-2
General
. . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Principles of Operation . . . . . . . . . . . . . . . . . 6-1
Galileo System . . . . . . . . . . . . . . . . . . . . 6-28
GPS Receivers . . . . . . . . . . . . . . . . . . . 6-30
Ground Element
Services
. . . . . . . . . . . . . . . . . . 6-29
. . . . . . . . . . . . . . . . . . . . . . . . 6-29
GNSS Accuracy . . . . . . . . . . . . . . . . . . . . 6-19
GNSS Augmentation . . . . . . . . . . . . . . . . 6-20
RAIM System . . . . . . . . . . . . . . . . . . . . 6-22
SBAS Systems . . . . . . . . . . . . . . . . . . . 6-22
GPS Modernization Signals . . . . . . . . . . . 6-24
CNAV Navigation Message . . . . . . . . . 6-25
L1C . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-26
L2CS . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-24
L5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-26
M Code . . . . . . . . . . . . . . . . . . . . . . . . . 6-27
GPS System . . . . . . . . . . . . . . . . . . . . . . . . 6-2
Control Segment . . . . . . . . . . . . . . . . . . 6-5
Space Segment
User Segment
. . . . . . . . . . . . . . . . . . . 6-3
. . . . . . . . . . . . . . . . . . . . 6-5
GPSG-1000 . . . . . . . . . . . . . . . . . . . . . . . . 6-1
Position Calculation . . . . . . . . . . . . . . . . . . 6-6
Atmospheric Delays
Clock Bias
. . . . . . . . . . . . . . . 6-17
. . . . . . . . . . . . . . . . . . . . . . 6-14
Code and Frequency Correlation
Measuring Distance
. . . . . . 6-8
. . . . . . . . . . . . . . . 6-11
Obtain Satellite Postions
SV’s to Acquire and Track
. . . . . . . . . . . 6-13
. . . . . . . . . . . 6-6
Time Delay Errors . . . . . . . . . . . . . . . . 6-16
Triangulation Calculations . . . . . . . . . . 6-14
SPS Standard Positioning Service
PPS Precise Positioning Service
. . . . . . 6-5
. . . . . . 6-6
Product Specifications
Accessories
. . . . . . . . . . . . . . . . . 7-1
. . . . . . . . . . . . . . . . . . . . . . . . 7-5
Battery
Coupler
. . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4
. . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3
Environmental
Generator
. . . . . . . . . . . . . . . . . . . . . . 7-4
. . . . . . . . . . . . . . . . . . . . . . . . . . 7-1
Physical Characteristics
. . . . . . . . . . . . . . 7-4
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T
Test Set Functions
. . . . . . . . . . . . . . . . . . . . 3-1
Calibration Function Window
Diagnostics Function Window
File Almanacs Function Window
File Routes Function Window
File Settings Function Window
GPS RX Function Window
Maintenance Function Window
Route Edit Edit Window
. . . . . . . . . . . . . . 3-21
Route Edit Stored Window
Route Function Window
. . . . . . . . . . . . . . 3-18
Setup Channels Window
Setup I/O Window
. . . . . . . . . . . . . 3-13
. . . . . . . . . . . . . . . . . . 3-14
Setup Motion Window
. . . . . . . . . . . . . . . 3-12
Setup Simulation Window
SV PRN Edit Window
. . . . . . . . . . . . . . . . 3-16
SV PRN Selection Function Window
System Function Window
Waypoint Edit Edit Window
Waypoint Edit Stored Window
Waypoint Edit Window
Waypoint Function Window
Testing GPS/Galileo Receivers
Antenna Coupler Installation
GPS Receiver Communication
RAIM Testing and SV Geometry
Sensitivity
. . . . . . . . . . . . . . . . . . . . . . . . . 4-9
Acquisition Sensitivity
. . . . . . . . . . . . . 4-11
C/No Measurement Options
Signal Tracking Sensitivity
Setup
. . . . . . . . . . . . . . . . . . . . . . 4-2
TTFF and Position Accuracy
Acquisition Cold Start
Acquisition Warm Start
. . . . . . . . . . . . . 4-13
Positional Accuracy
. . . . . . . . . . . . . . . 4-16
Reacquisition Hot Start
TTFF Accuracy
. . . . . . . . . . . . . . . . . . . 4-15
U
Upon Receipt
. . . . . . . . . . . . . . . . . . . . . . . . . 5-xi
Checking Equipment
. . . . . . . . . . . . . . . . 5-xii
Standard Items
. . . . . . . . . . . . . . . 5-xiii
Unpacking Test Set
. . . . . . . . . . . . . . . . . . 5-xi
User Interface Components
Function Keys
. . . . . . . . . . . . . . . . . . . . . . 2-9
Function Window Icons
Function Windows
. . . . . . . . . . . . . . 2-10
. . . . . . . . . . . . . . . . . . . 2-9
Launch Bar
. . . . . . . . . . . . . . . . . . . . . . . . . 2-8
Launch Bar Navigation
. . . . . . . . . . . . . . . 2-9
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As we are always seeking to improve our products, the information in this document gives only a general indication of the product capacity, performance and suitability, none of which shall form part of any contract. We reserve the right to make design changes without notice.
Go to http://ats.aeroflex.com/about-us/quality/standard-hardware-warranty for Sales and Service contact information.
EXPORT CONTROL WARNING: This document contains controlled technical data under the jurisdiction of the Export Administration Regulations (EAR), 15 CFR
730-774. It cannot be transferred to any foreign third party without the specific prior approval of the
U.S. Department of Commerce Bureau of Industry and Security (BIS). Violations of these regulations are punishable by fine, imprisonment, or both.
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