ashtech GG Surveyor User manual

™
Ashtech
1170 Kifer Road
Sunnyvale, CA USA 94086
Phone and Fax Numbers
• Main
• Voice: 408-524-1400
• Fax: [phone]
• Sales
• US: 800-922-2401
• International: 408-524-1670
• Fax: [phone]
•Europe
• Voice: 44-993-883-533
• Fax: [phone]
•Support
• US: 800-229-2400
• International: 408-524-1680
• Fax: [phone]
• BBS
• Direct: 408-524-1527
Internet
• [email protected]
• http://www.ashtech.com

ii GG Surveyor GPS+GLONASS Reference Manual
Copyright Notice
Copyright © 1998 Magellan Corporation. All rights reserved.
No part of this publication or the computer programs described in it may be repro-
duced, translated, stored in a retrieval system, or transmitted in any form or by any
means, electronic, mechanical photocopying, recording, or otherwise, without prior
written permission of Magellan. Your rights with regard to this publication and the
computer programs are subject to the restrictions and limitations imposed by the
copyright laws of the United States of America (“U.S.A.”) and/or the jurisdiction in
which you are located.
For information on translations and distribution outside the U.S.A. please contact
Ashtech.
Printed in the United States of America.
Part Number: 630199-01, Revision A
January, 1998
Trademarks
Ashtech® is a registered trademark of Magellan Corp. GG Surveyor , GPS+GLO-
NASS, GPS-RTK, REMOTE, EVALUATE, GPS TOPO, WinPRISM, Survey Con-
trol Software, Mine Surveyor, and the Ashtech logo are trademarks of Magellan
Corp. Pentium is a registered trademark of Intel Corporation. Husky and FS/2 are reg-
istered trademarks of Husky Computers Limited. All other product and brand names
are trademarks or registered trademarks of their respective holders.

iii
FCC Notice
The equipment described in this manual has been tested pursuant to Part 15 of the
FCC Rules and found to comply with the limits for a Class A digital device for use in
commercial business, and industrial environments. Operation is subject to the
following two conditions: (1) this device may not cause harmful interference, and (2)
this device must accept any interference received, including interference that may
cause undesired operation. These limits are designed to provide reasonable protection
against harmful interference when the equipment is operated in a commercial
environment. The equipment generates, uses, and can radiate radio frequency energy
and, if not installed and used in accordance with the instruction manual, may cause
harmful interference to radio and television reception. Operation of this equipment in
a residential area is likely to cause harmful interference in which case the user will be
required to correct the interference at his own expense.
If this equipment does cause interference to radio or television reception, which can
be determined by turning the equipment off and on, you can try to correct the
interference by one or more of the following measures:
• Reorient the receiving antenna.
• Relocate the receiver relative to the equipment which it interferes.
• Power the equipment from a different AC receptacle so that this
equipment and the interfered equipment are on different branch circuits.
If necessary, contact the Ashtech customer service department or an
authorized representative for additional advice.

iv GG Surveyor GPS+GLONASS Reference Manual
DISCLAIMER OF WARRANTIES AND LIMITATION OF
LIABILITY
LICENSOR AND ITS THIRD-PARTY SUPPLIERS MAKE NO WARRANTIES OR
REPRESENTATIONS, EXPRESS OR IMPLIED, REGARDING THE PROGRAM, MEDIA,
DOCUMENTATION, RESULTS OR ACCURACY OF DATA AND HEREBY EXPRESSLY
DISCLAIM ANY WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE AND NONFRINGEMENT. LICENSOR AND ITS THIRD-
PARTY SUPPLIERS DO NOT WARRANT THE PROGRAM WILL MEET YOUR
REQUIREMENTS OR THAT ITS OPERATION WILL BE UNINTERRUPTED OR ERROR-
FREE.
LICENSOR, its third-party suppliers, or anyone involved in the creation or deliver of the
Program or Documentation to you shall have no liability to you or any third-party for special,
incidental, indirect or consequential damages (including, but not limited to, loss of profits or
savings, downtime, damage to or replacement of equipment or property, or recover or
replacement of programs or data) arising from claims based in warranty, contract, tort (including
negligence), strict liability, or otherwise even if LICENSOR or its third-party suppliers have
been advised of the possibility of such claim or damages. The liability of LICENSOR and its
third-party suppliers for direct damages shall not exceed the actual amount paid for this Program
License.
Some states do not allow the exclusion of limitation of implied warranties or liability for
incidental or consequential damages, so the above limitations or exclusions may not apply to
you.
U.S. GOVERNMENT RESTRICTED RIGHTS
TheProgramandDocumentationareprovidedwithRESTRICTIVERIGHTS. Use,duplication,
or disclosure by the Government is subject to restrictions as set forth in subdivision (c)(1)(ii) of
the Rights in Technical Data and Computer Software clause at DFARS 252.227-7013 or
subdivision 9(C)(1) and (2) of the Commercial Computer Software - Restricted Rights 48 CFR
52.227.19, as applicable.
Should you have any questions concerning the License Agreement or the Limited Warranties
and Limitation of Liability, please contact in writing: Ashtech, 1170 Kifer Road, Sunnyvale,
CA 94086

Table of Contents v
Reliance Fundamentals
Chapter 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Technical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Performance Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Receiver Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
[5,2,1] Position Update Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
[5,2,1] Raw Measurement Update Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
[O] Raw Data Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
[P] Carrier Phase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
[U] RTCM Remote . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
[B] RTCM Base . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
[I] RAIM Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
[L] Pulse Per Second (1PPS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
[E] Event Marker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
[G] Geoid Height . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
[M] Magnetic Variation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
[J] Phase Differential Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
[C] Strobe Correlator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
[S] GLONASS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Chapter 2. Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Hardware Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Power/Input/Output Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Power Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
RF Interface Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Serial/Power Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Radio Interference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Chapter 3. Standard Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Connection Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Serial/Power Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Communication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

vi GG Surveyor GPS+GLONASS Reference Manual
Satellite Tracking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
File Directory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Saving Parameter Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Static Surveying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Performing a Static Survey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
System Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Changing Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Downloading Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Chapter 4. Advanced Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Receiver Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Input Messages to the GG Surveyor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Output Messages From the GG Surveyor . . . . . . . . . . . . . . . . . . . . . . . . . 21
Serial Port Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Parameter Settings and Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Default Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Data Recording . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
File Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
File Naming Convention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
DATALOGR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Position Mode/ALT Fix Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Altitude Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Time Shift Hold Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Daisy Chain Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Pulse Generation (1PPS) and Strobe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Photogrammetry Event Marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Time Tagging the Shutter Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Closed-Loop Technique (Advanced Trigger) . . . . . . . . . . . . . . . . . . . . . . 35
Data Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
5 Hz Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
NMEA Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Raw Data Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Signal to Noise Ratio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Satellite Search Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Ionospheric and Tropospheric Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
RAIM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
External Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Datums . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Point Poistioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Chapter 5. Differential and RTK Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Base Stations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Table of Contents vii
Setting Up a Differential Base Station . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Setting Up an RTK Base Station . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Setting Up a Combined Differential and RTK Base Station . . . . . . . . . . . 47
Advanced Base Station Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Recommended Advanced Parameter Settings for Base Stations . . . . 48
Antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Message Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Required Differential Update Rates . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Mask Angle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Base Station Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Base Station Antenna Offset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Using Reference Station ID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Reference Station Health . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Other RTCM Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Using a PC Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Using a Handheld Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Remote Stations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Setting Up a Differential Remote Station . . . . . . . . . . . . . . . . . . . . . . . . . 54
Setting Up an RTK Remote Station . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Advanced Remote Station Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Recommended Advanced Parameter Settings for Differential Remote
Stations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Recommended Advanced Parameter Settings for RTK Remote Stations . 56
Base Station RTCM Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Base Data Latency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Differential Accuracy vs. Base Data Latency . . . . . . . . . . . . . . . . . . . . . . 58
RTK Accuracy and Update Rates vs. Base Data Latency . . . . . . . . . . . . . 58
Synchronized RTK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Fast RTK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Position Latency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Float and Fixed Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Carrier Phase Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Reliability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Monitoring Accuracy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Required Number of Satellites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Mask Angles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Auto Differential Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
RTCM Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
RTCM 104 Format, Version 2.2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Chapter 6. Command/Response Formats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Receiver Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Set Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

viii GG Surveyor GPS+GLONASS Reference Manual
Query Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
AIM: RAIM Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
ALT: Set Ellipsoid Height . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
ANT: Set Antenna Offsets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
CLK: Clock Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
CLM: Clear Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
CTS: Port Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
DSC: Store String . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
DSY: Daisy Chain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
DTG: GLONASS Time Shift . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
DTM: Datum Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
DUG: UTC-GPS Time Difference . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
ELM: Raw Data Elevation Mask . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
EPG: Set Kinematic Epoch Counter . . . . . . . . . . . . . . . . . . . . . . . . . 81
EXF: Set Frequency Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
FIL: Close or Delete File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
FIX: Altitude Fix Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
FLS: Receiver File Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
FSS: Get System File Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
GTF: Set GLONASS Time Shift . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
GTM: GLONASS Time Shift Relative or Fixed . . . . . . . . . . . . . . . . 86
GTP: Set Priority of GLONASS Time Shift . . . . . . . . . . . . . . . . . . . 86
HDP: Horizontal Dilution of Precision . . . . . . . . . . . . . . . . . . . . . . . 86
INF: Set Session Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
INI: Receiver Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
ION: Set Ionospheric Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
LPS: Loop Tracking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
LTZ: Set Local Time Zone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
MRX: Set Transformation Matrix from PZ-90 to WGS-84 . . . . . . . . 92
MSV: Set Minimum Satellites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
PAR: Query Receiver Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
PDP: Position Dilution of Precision . . . . . . . . . . . . . . . . . . . . . . . . . . 95
PEM: Position Elevation Mask . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
PHE: Photogrammetry Edge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
PMD: Position Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
POP: Position Fix Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
POS: Set Antenna Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
POS CUR: Set Antenna to Current Computed Position . . . . . . . . . . 98
POW: Battery Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
PPO: Point Positioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
PPS: 1 PPS Pulse Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
PRJ: Set Session Logging Information . . . . . . . . . . . . . . . . . . . . . . 101

Table of Contents ix
PRT: Port Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
RCI: Recording Interval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
REC: Turn Data Recording On/Off . . . . . . . . . . . . . . . . . . . . . . . . . 103
RID:Receiver ID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
RIO: Request for Receiver ID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
RNG: Set Data Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
RST: Reset Receiver to Default Parameters . . . . . . . . . . . . . . . . . . . 105
SAV: Save User Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
SIT: Set Site Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
SMI: Code Measurement Smoothing . . . . . . . . . . . . . . . . . . . . . . . . 105
SMV: Speed Filtering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
SNR: Set Signal-to-Noise Ratio . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
SPD: Serial Port Baud Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
STA: Show Status of Satellites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
STB: Measurement Strobe Parameters . . . . . . . . . . . . . . . . . . . . . . . 107
SVP: Select Satellite to Use in Position Computation . . . . . . . . . . . 108
SVS: Satellite Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
SYS: Set Navigational System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
TDP: Time Shift Dilution of Precision . . . . . . . . . . . . . . . . . . . . . . . 109
TSC: Set Type of Time Scale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
UDD: Set User-Defined Datum . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
USE: Use Satellites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
USP: Select Satellite to Use in Position Computation . . . . . . . . . . . 113
UTS: Synchronize with GPS Time . . . . . . . . . . . . . . . . . . . . . . . . . . 113
VDP: Vertical Dilution of Precision . . . . . . . . . . . . . . . . . . . . . . . . . 114
Raw Data Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Set Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Query Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
MCA: Enable/Disable MCA Message . . . . . . . . . . . . . . . . . . . . . . . 117
PBN: Enable/Disable PBN Message . . . . . . . . . . . . . . . . . . . . . . . . . 119
RAW: Setting Query Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
SAG: Enable/Disable GLONASS Satellite Almanac Message . . . . 121
SAL: Enable/Disable GPS Satellite Almanac Message . . . . . . . . . . 123
SNG: Enable/Disable GLONASS Ephemeris Data . . . . . . . . . . . . . 124
SNV: Enable/Disable GPS Ephemeris Data . . . . . . . . . . . . . . . . . . . 126
NMEA Data Message Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
Set Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
Query Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Response message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
ALL: Disable All NMEA Messages . . . . . . . . . . . . . . . . . . . . . . . . . 132
AIM: Receiver Autonomous Integrity Monitor Message . . . . . . . . . 132
GGA: GPS Position Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134

x GG Surveyor GPS+GLONASS Reference Manual
GLL: Latitude, Longitude Message . . . . . . . . . . . . . . . . . . . . . . . . . 137
GRS: Satellite Range Residual Message . . . . . . . . . . . . . . . . . . . . . 138
GSA: DOP and Active Satellites Message . . . . . . . . . . . . . . . . . . . . 140
GSN: Signal Strength/Satellite Number Message . . . . . . . . . . . . . . 143
GST: Position Error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
GXP: Position Horizontal Message . . . . . . . . . . . . . . . . . . . . . . . . . 147
LTN: Latency Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
MSG: RTCM Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
PER: Set NMEA Send Interval . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
POS: Position Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
RMC: Recommended Minimum Course . . . . . . . . . . . . . . . . . . . . . 165
RRE: Satellite Residual and Position Error Message . . . . . . . . . . . . 166
SAT: Satellite Status Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
TCM: Enables/Disables RTCM Rover Data Message . . . . . . . . . . . 170
TTT: Event Marker Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
VTG: Velocity/Course Message . . . . . . . . . . . . . . . . . . . . . . . . . . . 172
ZDA: Time and Date Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
RTCM Response Message Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176
Set Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176
Query Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176
AUT: Enable/Disable Auto Differential Mode . . . . . . . . . . . . . . . . 177
BAS: Set Receiver as Differential Base Station . . . . . . . . . . . . . . . . 178
M36: RTCM Type 36 Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
MAX: Set Maximum Age of RTCM Differential Corrections . . . . 178
MSG: RTCM Type 16 Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
OFF: Disable Differential Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
QAF: Set Quality Threshold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
REM: Set Receiver as Differential Remote . . . . . . . . . . . . . . . . . . . 179
RTC: RTCM Differential Parameters . . . . . . . . . . . . . . . . . . . . . . . 179
SEQ: Check Sequence Number . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
SPD: Set RTCM Bit Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182
STH: Health of Reference Station . . . . . . . . . . . . . . . . . . . . . . . . . . 182
STI: Set Station Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
TYP: Enable Type of Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
CPD Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
Set Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
Query Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
AFP: Ambiguity Fixing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188
ANT: Antenna Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188
BAS: Base Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190
DLK: Data Link Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190
FST: Fast CPD Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193

Table of Contents xi
INF: CPD Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193
MAX: Maximum Age . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
MOD: CPD Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
POS: Set Base Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
RST: Reset CPD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
UBP: Use Base Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
Appendix A. GPS and GLONASS Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1
Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1
Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1
Integrity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1
Accuracy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2
Differential Position Accuracy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2
Basic Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2
Signal Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3
Differences in Signal Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3
Differences in Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3
Satellite orbits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-4
Geoid Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-4
Magnetic Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-5
Comparison of GPS and GLONASS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-5
GPS and GLONASS System Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-6
GPS+GLONASS Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-6
RTCM SC-104 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-6
NMEA 0183 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-7
Navigation Modes (Availability & Accuracy) . . . . . . . . . . . . . . . . . . . . . . . . A-8
Appendix B. Reference Datums and Ellipsoids . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1
Appendix C. Multipath Mitigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1
Evaluating Correlator Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1
Appendix D. Floating Point Data Representation . . . . . . . . . . . . . . . . . . . . . . . . . D-1
Sign Bit Field . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-1
Exponent Field . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-1
Fraction Field . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-1
The Represented Value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-2
Single-Precision Float . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-2
Double-Precision Float . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-3
Appendix E. Global Product Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-1
Solutions for Common Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-1
Corporate Web Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-3

xii GG Surveyor GPS+GLONASS Reference Manual
Ashtech Bulletin Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .E-3
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .E-3
Supported Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .E-4
Training Courses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .E-4
Repair Centers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .E-5
Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Index-1

List of Figures xiii
Reliance Fundamentals
Figure 2.1: GG Surveyor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Figure 2.2: DB25 Connector J101. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Figure 2.3: Serial/Power Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Figure 3.1: Antenna Groove . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Figure 4.1: $PASHR,PAR Default Response Message . . . . . . . . . . . . . . . . . 23
Figure 4.2: $PASHR,RAW Default Response Message. . . . . . . . . . . . . . . . . 23
Figure 4.3: $PASHR,RTC Default Response Message . . . . . . . . . . . . . . . . . 24
Figure 4.4: $PASHR,CPD Default Response Message . . . . . . . . . . . . . . . . . 24
Figure 4.5: GG Surveyor File Naming Convention . . . . . . . . . . . . . . . . . . . . 28
Figure 4.6: Relationship of GPS Time in PBN Record to 1 PPS Pulse . . . . . 32
Figure 4.7: 1PPS Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Figure 4.8: Photogrammetry Timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Figure 4.9: Closed Loop Technique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Figure 4.10: Rotation and Translation Between Coordinate Systems. . . . . . . . 42
Figure 4.11: Point Positioning Mode Position Error - GPS Only. . . . . . . . . . . 43
Figure 5.1: Combined Differential/RTK Base Station and Remote Operation57
Figure 5.2: DGPS and GLONASS Accuracy . . . . . . . . . . . . . . . . . . . . . . . . . 58
Figure 5.3: Convergence of Float Solution Following Reset . . . . . . . . . . . . . 62
Figure 5.4: Typical GST Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Figure 6.1. Typical $PASHR,PAR Response Message . . . . . . . . . . . . . . . . . 94
Figure 6.2: Rotation and Translation Between Coordinate Systems. . . . . . . 112
Figure A.1: GG Surveyor Code Differential Horizontal Position Decay . . . A-9
Figure C.1: Relative Performance of Multipath Mitigation Techniques . . . . C-2

xiv GG Surveyor GPS+GLONASS Reference Manual

List of Tables xv
Reliance Fundamentals
Table 1.1: Technical Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Table 1.2: Accuracy as Function of Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Table 1.3: GG Surveyor Receiver Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Table 2.1: GG Surveyor Front Panel Description . . . . . . . . . . . . . . . . . . . . . . . . . 7
Table 2.2: J101 Connector Pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Table 4.1: Default Receiver Parameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Table 4.2: File Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Table 4.3: GG Surveyor Recording Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Table 4.4: PPS and Photogrammetry Accuracy. . . . . . . . . . . . . . . . . . . . . . . . . . 33
Table 4.5: Raw Data Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Table 4.6: External Frequency Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Table 4.7: Ellipsoid Parameters for WGS-72 and WGS-84 . . . . . . . . . . . . . . . . 41
Table 5.1: Differential Base Station Commands . . . . . . . . . . . . . . . . . . . . . . . . . 45
Table 5.2: RTK Base Station Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Table 5.3: Base Station Commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Table 5.4: Message Size for RTCM Messages 18 and 19 . . . . . . . . . . . . . . . . . . 50
Table 5.5: Minimum Baud Rates for RTCM Messages 18 and 19 . . . . . . . . . . . 50
Table 5.6: Maximum Number of Satellites Above a 4° Mask Angle . . . . . . . . . 51
Table 5.7: Differential Remote Station Commands. . . . . . . . . . . . . . . . . . . . . . . 54
Table 5.8: RTK Remote Station Command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Table 5.9: Actual achieved reliability results with AFP settings of 99 and 99.9. 61
Table 5.10: Auto Differential Modes and Position Output . . . . . . . . . . . . . . . . . . 65
Table 5.11: RTCM Message Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Table 6.1: Command Parameter Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Table 6.2: Receiver Set/Query Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Table 6.3: Antenna Offsets Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Table 6.4: ANT Message Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Table 6.5: CLK Response Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Table 6.6: CLM Message Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Table 6.7: Daisy Chain Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Table 6.8: GPS-UTC Time Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
Table 6.9: EXF Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Table 6.10: EXF Response Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Table 6.11: FLS Response Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Table 6.12: FSS Response Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Table 6.13: INF Command Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Table 6.14: INF Response Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Table 6.15: Reset Memory Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

xvi GG Surveyor GPS+GLONASS Reference Manual
Table 6.16: Ionosphere Data Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Table 6.17: MRX (PZ-90 to WGS-84) Structure . . . . . . . . . . . . . . . . . . . . . . 93
Table 6.18: $PASHR,PAR Response Message Parameters . . . . . . . . . . . . . . 94
Table 6.19: Position Mode Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
Table 6.20: POS Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Table 6.21: POW Parameter Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Table 6.22: POW Message Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
Table 6.23: PPS Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Table 6.24: PPS Response Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Table 6.25: PRJ Structure, Current Project Information. . . . . . . . . . . . . . . . 101
Table 6.26: Serial Port Baud Rate Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
Table 6.27: Raw Data Update Rate Options . . . . . . . . . . . . . . . . . . . . . . . . . 102
Table 6.28: RIO Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
Table 6.29: Baud Rate Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Table 6.30: STB Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
Table 6.31: UDD Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Table 6.32: Ellipsoid Parameters for WGS-72 and WGS-84 . . . . . . . . . . . . 111
Table 6.33: Raw Data Commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
Table 6.34: MCA Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
Table 6.35: PBN Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Table 6.36: $PASHQ,RAW Response Parameters. . . . . . . . . . . . . . . . . . . . 121
Table 6.37: SAG (GLONASS Almanac) Structure . . . . . . . . . . . . . . . . . . . 122
Table 6.38: SAL (Almanac) Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Table 6.39: SNG GLONASS Ephemeris Data Structure . . . . . . . . . . . . . . . 125
Table 6.40: SNV (Ephemeris) Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
Table 6.41: NMEA Response Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Table 6.42: GLL Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Table 6.43: NMEA Data Message Commands. . . . . . . . . . . . . . . . . . . . . . . 131
Table 6.44: RAIM Response Message Structure . . . . . . . . . . . . . . . . . . . . . 133
Table 6.45: GGA Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
Table 6.46: Typical GGA Response Message . . . . . . . . . . . . . . . . . . . . . . . 136
Table 6.47: GLL Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
Table 6.48: Typical GLL Response Message . . . . . . . . . . . . . . . . . . . . . . . . 138
Table 6.49: GRS Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Table 6.50: Typical GPGRS Response Message . . . . . . . . . . . . . . . . . . . . . 139
Table 6.51: Typical GLGRS Response Message . . . . . . . . . . . . . . . . . . . . . 140
Table 6.52: GSA Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Table 6.53: Typical GPGSA Response Message . . . . . . . . . . . . . . . . . . . . . 141
Table 6.54: Typical GLGSA Response Message . . . . . . . . . . . . . . . . . . . . . 142
Table 6.55: GSN Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
Table 6.56: Typical GPGSN Response Message . . . . . . . . . . . . . . . . . . . . . 144
Table 6.57: Typical GLGSN Response Message . . . . . . . . . . . . . . . . . . . . . 145

List of Tables xvii
Table 6.58: GST Message Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Table 6.59: Typical GST Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
Table 6.60: GXP Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
Table 6.61: Typical GXP Response Message . . . . . . . . . . . . . . . . . . . . . . . . 148
Table 6.62: $GPMSG Structure for RTCM Message Types 1 and 9 . . . . . . 150
Table 6.63: $GPMSG Response for RTCM Messages 1, 31, and 9, 34 . . . . 151
Table 6.64: $GPMSG Structure for RTCM Message Types 3 and 32 . . . . . 152
Table 6.65: $GPMSG Response for RTCM Message Type 3. . . . . . . . . . . . 153
Table 6.66: $GPMSG Structure for RTCM Message Types 16 and 36 . . . . 154
Table 6.67: $GPMSG Response, RTCM Message Type 16 . . . . . . . . . . . . . 154
Table 6.68: $GPMSG Structure for RTCM Message Type 18 . . . . . . . . . . . 155
Table 6.69: $GPMSG Response for RTCM Message 18 . . . . . . . . . . . . . . . 156
Table 6.70: $GPMSG Structure for RTCM Message Type 19 . . . . . . . . . . . 158
Table 6.71: $GPMSG Response for RTCM Message 19 . . . . . . . . . . . . . . . 159
Table 6.72: $GPMSG Structure for RTCM Message Type 22 . . . . . . . . . . . 161
Table 6.73: $GPMSG Response for RTCM Message Type 22. . . . . . . . . . . 161
Table 6.74: PER (NMEA Output Rate) Range Options . . . . . . . . . . . . . . . . 162
Table 6.75: POS Response Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
Table 6.76: Typical POS Response Message. . . . . . . . . . . . . . . . . . . . . . . . . 164
Table 6.77: RMC Response Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
Table 6.78: RRE Response Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
Table 6.79: $GPRRE Response Message . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
Table 6.80: $GLRRE Response Message . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
Table 6.81: SAT Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
Table 6.82: Typical SAT Response Message . . . . . . . . . . . . . . . . . . . . . . . . 169
Table 6.83: TCM Response Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
Table 6.84: TTT Message Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172
Table 6.85: Example TTT Response Message. . . . . . . . . . . . . . . . . . . . . . . . 172
Table 6.86: VTG Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173
Table 6.87: Typical VTG Response Message . . . . . . . . . . . . . . . . . . . . . . . . 173
Table 6.88: ZDA Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
Table 6.89: Typical ZDA Response Message . . . . . . . . . . . . . . . . . . . . . . . . 175
Table 6.90: RTCM Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
Table 6.91: RTC Response Message Structure . . . . . . . . . . . . . . . . . . . . . . . 180
Table 6.92: Bit Rate Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182
Table 6.93: Reference Station Health Codes . . . . . . . . . . . . . . . . . . . . . . . . . 182
Table 6.94: Base Station Message Types and Period Ranges . . . . . . . . . . . . 183
Table 6.95: CPD Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186
Table 6.96: $PASHQ,CPD Response Descriptions. . . . . . . . . . . . . . . . . . . . 187
Table 6.97: CPD,AFP Parameter Table. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188
Table 6.98: CPD,ANT Parameter Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189
Table 6.99: CPD,ANT Message Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . 189

xviii GG Surveyor GPS+GLONASS Reference Manual
Table 6.100: CPD,DLK Message Structure . . . . . . . . . . . . . . . . . . . . . . . . . . 190
Table 6.101: CPD,DLK Response Message Example - Rover. . . . . . . . . . . . 191
Table 6.102: CPD,DLK Response Message Example - Base Station. . . . . . . 192
Table 6.103: INF Message Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
Table 6.104: CPD,MOD Parameter Table . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
Table 6.105: CPD,MOD Message Structure. . . . . . . . . . . . . . . . . . . . . . . . . . 195
Table 6.106: CPD,POS Parameter Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
Table 6.107: CPD,UBP Parameter Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198
Table A.1: Comparison of GPS and GLONASS. . . . . . . . . . . . . . . . . . . . . A-5
Table A.2: RTCM SC-104 Messages for GPS and GLONASS . . . . . . . . . A-7
Table A.3: Accuracy as a Function of Constellation . . . . . . . . . . . . . . . . . . A-8
Table A.4: Approximate Position Error, Mixed GPS+GLONASS . . . . . . . A-9
Table B.1: Available Geodetic Datums . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1
Table B.2: Reference Ellipsoids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-5
Table D.1: Single-Precision Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-2
Table D.2: Double-Precision Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-3
Table E.1 GPS Product Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .E-1

Introduction 1
Introduction
The GG Surveyor™ is the first all-in-view GPS+GLONASS™ receiver. It’s revolutionary
design allows smooth integration into a wide range of positioning applications on land, sea
or in the air.
One of the primary advantages of GPS+GLONASS is increased satellite coverage. With a
total of 40 healthy satellites, there are 60% more satellites available for position
computation than GPS alone. Thus, GPS+GLONASS is extremely beneficial in
obstructed operating environments, such as in cities, mountainous areas, under tree cover,
or other areas where much of the sky and many of the satellites can be blocked.
To take advantage of the increased satellite availability, the GG Surveyor has 12 channels
for L1 GPS and 12 Channels for L1 GLONASS, providing all-in-view tracking for both
constellations. Autonomous GPS+GLONASS positions typically have 16 meter
accuracies compared with 100 meters for GPS alone.
Differential corrections and RTK messages are available for both GPS and GLONASS
providing real-time, on-the-fly centimeter accuracy when the GG Surveyor is used with a
base station and data link.
Functional Description
The GPS constellation contains 26 usable satellites. As of December 1997, the GLONASS
constellation has 13 usable satellites of the planned 24 satellites full constellation. The GG
Surveyor provides the capability to track up to 24 GPS and GLONASS satellites
simultaneously. As the GG Surveyor locks onto the signal generated by each satellite,
information (ephemeris data) about the position of each satellite is automatically
downloaded and stored in receiver memory. Once the ephemeris data is collected, the GG
surveyor can compute its own position.
The GG Surveyor calculates three-dimensional position and velocity when tracking any
combination of five satellites (e.g. 3 GPS and 2 GLONASS). By holding the GPS-
GLONASS clock offset fixed, the GG Surveyor calculates a 3D position with any
combination of 4 satellites (e.g., 2 GPS and 2 GLONASS). By also holding the altitude
fixed, the GG Surveyor calculates a 2D position with any combination of 3 satellites.
Up to 5 independent measurements are determined per second, with no interpolation or
extrapolation from previous solutions. The position and velocity computations are
performed using all the satellites in view simultaneously (up to 16 when in 5 Hz mode).
The GG Surveyor uses a Doppler measurement technique for computing on-the-fly
velocity (no dependence on the previous position). All computations are accomplished

2 GG24 Surveyor GPS+GLONASS Reference Manual
relative to the World Geodetic System WGS-84 reference ellipsoid when the receiver
is used in GPS or MIX mode, and in PZ-90 when in GLN only mode.
Upon application of power, the GG Surveyor runs a self-test of internal memories,
and thereafter periodically self-tests various functions during normal operation. Test
results are stored for commanded output. After self-test, the GG Surveyor initializes
the battery-backed RAM. If the battery-backed-up RAM fails self-test (due, for
example, to a low battery condition), the GG Surveyor clears and reports the loss of
stored data, then initializes the 24 channels and begins searching for all satellites
within the field of view of the antenna.
Technical Specifications
Table 1.1 lists the technical specifications of the GG Surveyor.
Table 1.1: Technical Specifications
Characteristic GG Surveyor Specifications
Tracking • 12 channels L1 GPS code and carrier
• 12 channels L1 GLONASS code and carrier
Size 7.2 cm wide × 5.8 cm height × 22.5 cm depth
Weight 3.4 lbs
Operating temperature -30° to +55°C
Storage temperature -40° to +85°C
Environment
• Humidity
• Vibration
• Shock
• Resistant to wind-driven rain and dust to MIL-STD-810E
• N/A
• N/A
Power consumption 3 watts
Input Voltage 6 to 15 VDC
Speed (Maximum) 1,000 knots (higher velocities available under validated export
license)
Altitude (Maximum) 60,000 ft (higher altitude available under validated export license)
Interface • Three bi-directional RS-232 ports via DB 25 connector up to
115,200 bps
• One antenna port
• Event marker and 1PPS via DB25 connector
• optional external reference connector
• optional radio antenna connector