Z-Family Technical Reference Manual Ashtech 1170 Kifer Road Sunnyvale, CA USA 94086 Phone and Fax Numbers • Main • • • Sales • • • • Voice: 44-993-883-533 Fax: 44-993-883-977 Support • • • • US: 800-922-2401 International: 408-524-1670 Fax: 408-524-1500 Europe • • • Voice: 408-524-1400 Fax: 408-524-1500 US: 800-229-2400 International: 408-524-1680 Fax: 408-524-1500 BBS • Direct: 408-524-1527 Internet • support@ashtech.com • http://www.ashtech.
Copyright Notice Copyright © 1998 Magellan Corporation. All rights reserved. No part of this publication or the computer programs described in it may be reproduced, 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.
Trademarks Z-Surveyor, Z-FX, Z-Sensor, Z-Eurocard, GPSTopo, and the Ashtech logo are registered trademarks of Magellan. All other product and brand names are trademarks or registered trademarks of their respective holders.
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Table of Contents Chapter 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Reliance Fundamentals Performance Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Receiver Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 [B] RTCM Base . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Synchronization to GPS Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Default Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Multipath Mitigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Evaluating Correlator Performance . . . . . . . . . . . . . . . . . . . . . . .
RTCM Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Chapter 4. Understanding RTK/CPD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 Monitoring the CPD Rover Solution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 How to tell if the integer ambiguities are fixed? . . . . . . . . . . . . . . . . . . . . 51 Data Link Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CLM: Clear/Reformat PCMCIA Card . . . . . . . . . . . . . . . . . . . . . . . . 80 CTS: Port Protocol Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 DSC: Store Event String . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 DSY: Daisy Chain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 ELM: Recording Elevation Mask . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 EPG: Epoch Counter . . . . . . . . . . . . . . . . .
RNG: Data Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 RST: Reset Receiver to default . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 RTR: Real-Time Error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 SAV: Save User Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 SES: Session Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 SID: Serial Number . . . . . . . . . . . .
GRS: Satellite Range Residuals . . . . . . . . . . . . . . . . . . . . . . . . . . . . GSA: DOP and Active Satellite Messages . . . . . . . . . . . . . . . . . . . . GSN: Signal Strength/Satellite Number . . . . . . . . . . . . . . . . . . . . . . GSV: Satellites in View Message . . . . . . . . . . . . . . . . . . . . . . . . . . GXP: Horizontal Position Message . . . . . . . . . . . . . . . . . . . . . . . . . MSG: Base Station Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DYN: Rover Dynamics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204 ENT: Use Current Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205 EOT: End of Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205 FST: Fast CPD Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206 INF: CPD Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206 MAX: Max Age for CPD Correction . . . . .
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List of Figures List of Figures PCMCIA File Card Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Z-Family File Naming Convention. . . . . . . . . . . . . . . . . . . . . . . . . 8 Event Marker Time Measurement . . . . . . . . . . . . . . . . . . . . . . . . 13 Closed Loop Technique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Relative Performance of Multipath Mitigation Techniques . . . . . 22 Detailed View of Multipath Mitigation Performance. . . . . . . . . .
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List of Tables List of Tables Accuracy as Function of Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Z-Family Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 File Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Z-Family Recording Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Position Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 6.13: Table 6.14: Table 6.15: Table 6.16: Table 6.17: Table 6.18: Table 6.19: Table 6.20: Table 6.21: Table 6.22: Table 6.23: Table 6.24: Table 6.25: Table 6.26: Table 6.27: Table 6.28: Table 6.29: Table 6.30: Table 6.31: Table 6.32: Table 6.33: Table 6.34: Table 6.35: Table 6.36: Table 6.37: Table 6.38: Table 6.39: Table 6.40: Table 6.41: Table 6.42: Table 6.43: Table 6.44: Table 6.45: Table 6.46: Table 6.47: Table 6.48: Table 6.49: Table 6.50: Table 6.51: Table 6.52: Table 6.53: Table 6.
Table 6.55: Table 6.56: Table 6.57: Table 6.58: Table 6.59: Table 6.60: Table 6.61: Table 6.62: Table 6.63: Table 6.64: Table 6.65: Table 6.66: Table 6.67: Table 6.68: Table 6.69: Table 6.70: Table 6.71: Table 6.72: Table 6.73: Table 6.74: Table 6.75: Table 6.76: Table 6.77: Table 6.78: Table 6.79: Table 6.80: Table 6.81: Table 6.82: Table 6.83: Table 6.84: Table 6.85: Table 6.86: Table 6.87: Table 6.88: Table 6.89: Table 6.90: Table 6.91: Table 6.92: Table 6.93: Table 6.94: Table 6.95: Table 6.
Table 6.97: Table 6.98: Table 6.99: Table 6.100: Table 6.101: Table 6.102: Table 6.103: Table 6.104: Table 6.105: Table 6.106: Table 6.107: Table 6.108: Table 6.109: Table 6.110: Table 6.111: Table 6.112: Table 6.113: Table 6.114: Table 6.115: Table 6.116: Table 6.117: Table 6.118: Table 6.119: Table 6.120: Table 6.121: Table 6.122: Table 6.123: Table 6.124: Table 6.125: Table 6.126: Table 6.127: Table 6.128: Table 6.129: Table 6.130: Table 6.131: Table 6.132: Table 6.133: Table 6.134: Table 6.135: Table 6.
Table 6.159: Table 6.160: Table 6.161: Table A.1: Table A.2: Table B.1: Table B.2: List of Tables CPD,EOT Parameter Table. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205 INF Message Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206 CPD,MOD Parameter Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208 CPD,MOD Message Structure . . . . . . . . . . . . . . . . . . . . . . . . . . 208 MTP Parameter Table . . . . . . . . . . . . . . . . . . . . . . . . . .
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1 This manual provides detailed technical reference information for the Z-Surveyor, Z-FX, Z-Sensor, and Z-Eurocard (this group of products are commonly referred to as the Z-Family). For information about physical characteristics, description, and front panel operations, please refer to the receiver operations manual.
Table 1.1: Accuracy as Function of Mode Positioning Mode Real-time carrier phase differential in RTCMRTK format or DBEN format Typical Horizontal Accuracy (2drms), 5 SVs, PDOP<4 1.6cm +2ppm Maximum Update Rate 5Hz, (10Hz optional) Maximum Operating Range <15 kilometers (depending upon datalink) All accuracies were computed from multiple trials of live satellite data collected in the San Francisco Bay area with receivers and Geodetic III antennas under average multipath conditions.
Table 1.2: Z-Family Options (continued) Description (continued) 1,2,3 Observables J RTK Rover K RTK Base Introduction Option [B] RTCM Base The receiver has the ability to be set as an RTCM differential base station and can output real-time differential corrections when this option is enabled. The output will be in RTCM-104, Version 2.2 format message types 1,3,6, 16 and 22 as well as RTCM Carrier Differential 18, 19, 20, and 21. For messages 18, 19, 20, and 21, the K option is also required.
[M] Remote Monitoring The remote monitoring option allows the user to use the REMOTE.EXE to access and control the receiver via a modem from a remote location. This option is required for GPSTopoTM. [F] Fast Data Output This option enables the receiver to be programed to output both raw position data and NMEA messages or record data (if a PCMCIA card is present in the receiver) at user selectable frequencies up to 10Hz. Without this option, only frequencies up to 5Hz are available.
2 Operation This chapter describes receiver operations other than those available through the front panel. It is good practice to reset your receiver prior to operating it for the first time or when a system malfunction occurs. A reset of the internal memory clears the memory and restores the factory defaults. This reset does not affect data stored on the PCMCIA card.
Data Recording ( Z-Surveyor and Z-FX only) All data recording in the receiver (those that have memory capacity) is done on the PCMCIA data card also known as a PC card. The PC card is a compact and convenient way to store a lot of data. The amount of data that can be stored depends upon the size of the card. PC cards are available in sizes ranging from 2 to 85Mb. The PC card must be correctly inserted in the PC card slot in the memory compartment to record data.
directory or in a sub-directory. The receiver creates and maintains directories and files on the PC Card using the file structure illustrated in Figure 2.1. 1st session Operation 2nd session 3rd session Figure 2.1: PCMCIA File Card Structure Other files may be stored on the PC Card, although it is recommended that the PC Card only be used for storage of data because the $PASHS,CLM and $PASHS,FIL,D,99 will reformat the card and all files will be lost.
the raw data files begin with the letter “B”, so they are referred to as B-Files. A list of the files is shown in Table 2.1. Table 2.1: File Types File Type Description Format B-file Raw data-generally code and carrier phase data, position data, and SITE ID Binary E-file Satellite ephemeris data Binary S-file Site information data ASCII C-file Position Data ASCII M-file Event Marker files (photogrammetry) ASCII D-file Site attribute files ASCII Almanac file Binary ALMyy.
• Operation • • characters are replaced by underscores (“____”). In kinematic surveying it is common to change the site ID many times during the recording session. The site ID used for naming the session files is the LAST site ID entered during the session. The next character indicates the session identifier. This field automatically increments from A to Z when a new recording session is started.
Session Programming The Session Programming feature allows you to pre-set up to 10 observation sessions in the receiver. The receiver can then run unattended and will collect data on the data card only during the times that have been preset. Once set, the sessions will collect data during the preset session times every day. Or if desired, a session time offset can be programmed in that will shift the session start and end times by a set amount every day.
Position Mode/ALT Fix Mode Position Mode The receiver performs a position fix computation in four modes. The $PASHS,PMD command is used to select the mode. Table 2.3 describes these four modes. Table 2.3: Position Modes Operation Mode Description 0 At least four satellites with elevation equal to or above the elevation mask are needed to compute a position. All three polar coordinates are computed in this mode.
Chain mode, all commands entered in one serial port are passed back out through another serial port. The commands are not interpreted by the GPS receiver. The command $PASHS,DSY enables the Daisy Chain mode and allows the user to assign which serial ports to be used. A typical example of the use of Daisy Chain mode is communicating with a radio through a handheld. The radio and handheld are not directly connected but are both connected to the GPS receiver via separate serial ports.
rear panel of the receiver (refer to your individual receiver manual for pinout information). The event marker feature allows the event time to be stored in memory and downloaded using the DOWNLOAD program as an M-file, or output by using the $PASHS,NME,TTT command. At the rising or falling edge (selectable) of the trigger signal, the time is recorded in the receiver’s PC card. The trigger signal can be set to the falling edge using the $PASHS,PHE command.
are interpolated to compute the position of the camera at the time the picture was taken. For example, suppose the GPS measurements are recorded at the rate of one per second while the distance that the aircraft moves in ½ second is about 100 meters. The induced error between the position of the camera at the time the picture was taken and the GPS position fixes can be as much as 50 meters. To minimize the errors discussed above, the closed loop technique is recommended.
1PPS Out Operation By default, the receiver generates a TTL-level pulse every second within one microsecond of the GPS time for synchronization of external equipment. Refer to your individual receiver manual to determine signal location on the pinouts of the ports. This pulse can be offset using the $PASHS,PPS command (refer to “PPS: Pulse Per Second” on page 104). It can also synchronize either the rising edge (default) or the falling edge to the GPS time.
mode is set to off, in which case the highest rate is 1 Hz (if Fast CPD mode is on, 10 HZ is available). Also, if the [F] option is not installed, the highest output rate supported is 5Hz. Transferring GPS Data GPS data stored on the PC Card may be transferred to a computer for post-processing by loading the PC Card in a PCMCIA Card drive and then running the converter from Download to decompress the files to a normal format. Data can also be downloaded through one of the serial ports on the receiver.
receivers are moving together, their position measurements would be different, because each receiver will report a position for a snapshot taken at a different time. Operation Fortunately, if a receiver obtains measurements from four or more satellites it can determine its own internal clock error. In order to reduce the effects mentioned previously, most receivers use the computed clock error to periodically reset the internal receiver clock to remain close to GPS system time (within a millisecond).
Table 2.
Table 2.
Table 2.
Table 2.4: Default Values (continued) Parameter ANT offset Description Default Distance from Antenna Phase Center to Antenna Edge 00.0000 ANT horizontal azimuth Azimuth measured from Reference Point to Antenna Phase Center 00000.00 ANT horizontal distance Distance from Reference Point to Antenna Phase Center 00.0000 Operation Multipath Mitigation Overview Multipath occurs when GPS signals arrive at the receiver after being reflected off some object.
of the direct signal, for the Standard Correlator, the very well known Narrow Correlator and the new Ashtech Enhanced Strobe Correlator. The x-axis shows the multipath delay, which is the extra distance that the reflected signal travels compared to the direct signal. The y-axis shows the induced range error caused by a multipath signal with the indicated delay. As the multipath delay increases, the error oscillates between the positive and negative error envelope.
in the ideal correlation function, so it is usually almost impossible for the correlatorbase multipath integration to completely compensate for this error. Multipath Code Error Envelopes 10 8 4 2 Operation Tracking Error (meters) 6 Ashtech 0 Enhanced Strobe -2 Correlator -4 -6 -8 Narrow Standard Correlator -10 0 10 20 30 Multipath Delay (meters) 40 50 Figure 2.
amplifier (LNA) which is built into most Ashtech antenna assemblies. When using different antennas with the receiver it should be noted that differences in C/No. can be seen as a result of the above mentioned factors. If calibrating the C/No. reading of the receiver with a satellite constellation simulator at room temperature, realize that the noise figure of the LNA used will degrade the C/ No reading by the amount equal to the noise figure of the LNA. (C/No.
Once these parameters are entered, the user can select to use them through the $PASHS,ANR,x command with x indicating the following: where x is N—no antenna reduction is performed. The solution provided is the antenna phase center. where x is Y—Antenna reduction is performed.
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3 Differential and RTK Operations Real-time differential positioning involves a reference (base) station receiver computing the satellite range corrections and transmitting them to the remote stations. The reference station transmits the corrections in real time to the remote receivers via a telemetry link. Remote receivers apply the corrections to their measured ranges, using the corrected ranges to compute their position. As stand-alone, the receiver can compute a position to around 100 meters.
Table 3.1: Differential Base Station Commands (continued) Command Description $PASHS,RTC,BAS,x Turn on RTCM corrections on port x When this command is sent, a base station automatically sends RTCM message type 1 continuously. $PASHS,RTC,SPD,9 Set internal bit-rate for corrections to burst mode. $PASHS,SAV,Y Save settings Do not try to transmit corrections on the same receiver serial port you are using to set up the receiver from your PC.
Table 3.2: RTK Base Station Commands (continued) Command Description Turn on RTCM corrections on port B When this command is sent, a base station automatically sends RTCM message type 1 continuously. $PASHS,RTC,TYP,1,0 Turn off RTCM message type 1. $PASHS,RTC,TYP,3,1 Turn on RTCM message type 3. $PASHS,RTC,TYP,18,1 Turn on RTCM message type 18 & 19. $PASHS,RTC,TYP,22,1 Turn on RTCM message type 22. $PASHS,RTC,SPD,9 Set internal bit-rate for corrections to burst mode.
Table 3.3: RTK Base Station Commands (continued) Command Description $PASHS,RTC,TYP,3,1 Turn on RTCM message type 3. $PASHS,RTC,TYP,20,1 Turn on RTCM message type 20 & 21. $PASHS,RTC,TYP,22,1 Turn on RTCM message type 22. $PASHS,RTC,SPD,9 Set internal bit-rate for corrections to burst mode. $PASHS,SAV,Y Save settings The receiver is set as a base station which transmits RTCM messages types 20 and 21 every second, and types 3 and 22 every minute.
The receiver also transmits a BPS message (base position) every 30 seconds by default (the periodicity can be set with the $PASHS,CPD,PEB command). DBN messages are shorter than their RTCM equivalent, so they provide lower latency. If the data link is not very reliable, use RTCM messages because they can be used partially, unlike DBN messages, so in that configuration, the chances of obtaining a reasonable position solution are higher with RTCM than with DBN.
and 22 every minute. Following a power cycle it automatically starts transmitting these messages again (because you have saved the settings with the $PASHS,SAV,Y command). You can also set up the Base Station to use messages 20 & 21 instead of 18 & 19. You can not use DBN and RTCM messages on the same serial port. You can generate DBN from one port while generating RTCM from a different port.
setting is burst mode (9), which automatically adjusts the bit rate to the fastest possible rate based on the serial port baud rate: $PASHS,RTC,SPD,9 • • Differential and RTK Serial port baud rate. This should be as high as possible. RTCM message rate. This is the rate at which messages are generated. • RTK messages (RTCM 18 & 19, RTCM 20 & 21, Ashtech DBN) are the most important. They should be generated as fast as possible, ideally once per second.
Message size Table 3.6 lists the message size for RTCM messages 18 & 19 or 20 & 21. Table 3.6: Message Size for RTCM Messages 18 & 19 or 20 & 21 Number of Satellites Number of RTCM Words in Message Type 18/20. (30 bits/word) Number of RTCM Words in Message Type 19/21. (30 bits/word) 7 (2+1+7)*2 = 20 (2+1+7)*2 = 20 9 (2+1+9)*2 = 24 (2+1+9)*2 = 24 12 (2+1+12)*2 = 30 (2+1+12)*2 = 30 Table 3.7 lists the message size for Ashtech DBN messages. Table 3.
Table 3.8: Minimum Baud Rates for RTCM Messages 18 & 19 or 20 & 21 Number of Satellites Minimum baud rate (message period = T) Minimum standard baud rate (T = 5 sec) Minimum standard baud rate (T = 1 sec) 12 30*30*2*8/6*10/8*1/T 600 bps 4800 bps For Ashtech DBN messages, the required minimum baud rate is the DBN rate multiplied by 10/8. Table 3.9 lists the required baud rates. Table 3.
using a 24 hour simulation at 0° longitude. GPS geometry is primarily a function of latitude, and varies only slightly with longitude for a constant latitude. Table 3.10: Maximum Number of Satellites Above a 4° Mask Angle Latitude Maximum Number of GPS SVs 0° 11 10° 12 20° 11 30° 11 40° 11 50° 10 60° 11 70° 12 80° 11 90° 12 Mask Angle The Base station mask angle for RTK messages 18, 19, 20, & 21 is controlled by $PASHS,ELM.
may also be entered directly into the remote unit, using the $PASHS,CPD,POS and $PASHS,UBP commands. This reduces bandwidth requirements by obviating the need for messages 3 and 22. Base Station Antenna Offset If you set up the base station antenna over a known, surveyed point, you may enter the position of the surveyed point and the offset from this point to the antenna phase center. Or you may enter the phase center directly.
Filler: Message 6 Null Frame This message is provided for datalinks that require continuous transmission of data, even if there are no corrections to send. As many Messages 6 are sent as required to fill in the gap between two correction messages. Messages 6 are not sent in the burst mode ($PASHS,RTC,SPD,9) Special Message: Message 16 This message allows you to transmit an ASCII message from the base station.
which message types to expect, it will automatically use whatever it receives on serial port c. Table 3.11: Differential Remote Station Commands Command Description $PASHS,RST Reset the receiver to factory defaults $PASHS,RTC,REM,c Set the receiver as a remote station, receiving corrections on serial port c $PASHS,SPD,c,d Set the baud rate of serial port c to the same as the radio providing the corrections. $PASHS,SAV,Y Save settings Differential and RTK You have now set up the remote station.
Send the following commands to the receiver. The receiver accepts RTCM RTK data in message types 18 (Carrier phase data) and 19 (Code phase data), 20 (carrier phase corrections) and 21 (code phase corrections), 3 and 22 (Base station position). Table 3.
Advanced Remote Station Operation Base Station Data Both Differential remote stations and RTK remote stations automatically extract the messages needed from the data coming in to the designated serial port. So you can set up a combined Differential/RTK base station (see "Setting Up a Combined Differential and RTK Base Station" on page 31), and operate DGPS remote receivers and RTK remote receivers. You can also send RTCM messages from one serial port, while sending Ashtech DBN messages from another port.
Figure 3.1: Combined Differential/RTK Base Station and Remote Operation Ashtech remote receivers (both Differential and RTK) operate with any base station that generates the industry standard RTCM messages. Base Data Latency Both Differential and RTK operation are better the lower the latency of the BaseRemote data link. To minimize latency set the baud rate of the radios as high as possible, and use radios that are optimized for low latency GPS operation, such as the Ashtech SSRadio.
In the case of CPD with RTCM 18 & 19 or 20 & 21, if the message is partially received, for enough satellites to compute a position, the age increments, but a position solution is still derived, and continues to be output even if MAX AGE is reached. Differential Accuracy vs. Base Data Latency Figure 2 shows the growth of position error with increasing latency for DGPS. Differential and RTK Figure 3.2: DGPS Accuracy RTK Accuracy and Update Rates vs.
Fast RTK In this mode the remote receiver’s update rate is selectable up to 10Hz, and is independent of the rate at which it receives type 18, 19, 20, 21, or DBN messages. Use the command $PASHS,NME,PER to control the update rate. The latency of position is less than 50 milliseconds. Typical accuracy (1σ horizontal) in centimeters is equal to the base-remote data latency in seconds, for data latency of up to 10 seconds.
initialization. This carrier phase initialization is only necessary following power-on, or after the receiver has lost lock on the satellites (e.g. after passing under a bridge). The receiver performs carrier phase initialization automatically. The receiver does not have to be stationary while initializing. Once the receiver is initialized it will provide centimeter-level accuracy, while moving, in real time.
c. Fixed solution, formal reliability = 99% (default) d. Fixed solution, formal reliability = 99.9% The command $PASHS,CPD,AFP controls the ambiguity fix parameter. The four choices of formal reliability for fixed solution are provided to allow you to trade off speed with reliability. The AFP setting controls the internal thresholds of the receiver so that the expected statistical reliability of getting correctly fixed integers is 90%, 95%, 99%, or 99.9% respectively.
Mask Angles At the remote station the position elevation mask is always controlled by $PASHS,PEM, whether the receiver is in Differential mode or RTK mode. Auto Differential Mode When a user operates a rover receiver in differential mode (either code phase or carrier phase), a failure at the base station or in the data link causes the rover receiver to cease outputting differentially corrected positions.
corrections are automatically processed by the receiver. For diagnostic purposes, the RTCM messages can be output in an ASCII format on the rover side via the MSG command (See “MSG: Base Station Message” on page 166). On initial power-up or after use of the $PASHS,RST reset to defaults command, the receiver default automatic differential mode is OFF, and the default is 60 seconds for the maximum age of an RTCM differential correction above which it will not be used.
The receiver uses the six-of-eight format (data bits a1 through a 6 of an eight-bit byte) for communication between the reference station and user equipment. When the receiver is used as remote equipment and the RTCM and RTK remote options are enabled, it can accept any type of RTCM message. However it decodes types 1, 2, 3, 6, 9, 16, 18, 19, 20, 21, and 22 uses only types 1, 2, and 9 for differential corrections and types 3, 18, 19, 20, 21, and 22 for RTK corrections.
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4 Understanding RTK/CPD This chapter provides CPD operation in more detail by describing CPD solution monitoring, solution output and storage, trouble shooting and performance optimization. RTCM reference station setup is also described briefly. The front panel setup does not provide access to CPD rover mode, which must be configured by using serial commands (CPD base can be set via the front panel for the Z-Surveyor and Z-Fx).
In ASCII $PASHR,CBN message, a “1” in the third digit of the solution type field indicates the ambiguities are fixed. $PASHR,CBN,212501.00,????,08,001.2,3722.3784261,N,12159.8417992,W,00005.0847,00.011,00.011,00.012,-00.000,+00.000,-00.000,221001,+000.000,000.001,+000.001, 00.000,00.000,00.000*6C In a CBN message, the solution RMS values represent one-sigma solution accuracy. A fixed ambiguity solution should have all three RMS values < 0.03 meters, with PDOP < 4.0.
Other solution messages are also available for query, and not to output periodically like CBN messages. These messages are UBN and OBN. The UBN message gives CPD position, velocity, and statistical information in binary format. The OBN message gives CPD vector and site information in binary format.
5. Wait for more than two seconds, and then enter the next command to log the solution to the OBN file: 6. Verify the site name in the vector solution. If it does not match, query again. 7. You can move the GPS antenna to the next site. $PASHQ,OBN Solution Storage The CPD solution can be stored in receiver memory in Ranger mode 2 or Ranger mode 4. If your receiver has a PC data card, you can store the raw measurements and the solution information into the receiver’s PC data card.
Troubleshooting The following problems are sometimes encountered by users new to the receiver. If your system isn’t working properly, please refer to this list. If you need further assistance, please call a customer service representative. Table 4.1: Troubleshooting Tips Symptom PC cannot communicate with receiver Action • • • • receiver not in RTK Rover mode • • • Base beeps • Verify that the receiver is in CPD base mode or in CPD rover mode.
Table 4.1: Troubleshooting Tips (continued) Symptom No CPD solution Action • • • CPD solution is intermittent and the Rover beeps • • • Cannot get fixed CPD solution • • • CPD solutions are not being stored in the Rover • • • • Cannot get the CPD solution • output in real-time • 56 Verify that there are at least four common satellites between the base and the rover, using $PASHQ,CPD,INF command.
System Performance Optimization CPD Solution Parameters Table 4.2 lists the commands which are provided for optimizing the CPD operations. Table 4.
If the ambiguities are fixed incorrectly, the satellite geometry must change appreciably before the ambiguities will again fix correctly. For a static rover, this will happen within approximately 10 minutes, or when a new satellite is acquired. Figure 4.1: Ambiguity Fix Test Results Dynamics: $PASHS,CPD,DYN Select the dynamics for the fastest acceleration you expect to be moving. If the dynamics are not set properly, the CPD solution will be less accurate.
Fast CPD: $PASHS,CPD,FST Fast CPD off achieves the ultimate in GPS accuracy. With Fast CPD off, subcentimeter position solution accuracy can be obtained with fixed integer ambiguities. However, it suffers from solution delay. This delay is caused by measurement and radio link delays. The measurement delay is about 1 second. Typical radio data link delays are about 1 second also. DLf and Tf are not shown in $PASHR,CPD message when Fast CPD is off.
Initialization: $PASHS,CPD,RST If you wish to reset the carrier phase cycle ambiguities that have been found, send $PASHS,CPD,RST command. Note that your position accuracy will temporarily degrade and you should wait until the ambiguities are fixed again before expecting centimeter accuracy.
Table 4.3: Default RTCM message schedules Message Type Interval (seconds) 1 1 2 0 (off) 3 60 (1 minute) 6 ON 16 Off 18/19 1 20/21 1 22 60 (one minute) For CPD (RTK) application only, you can turn on type 3 and/or 22 and type 18/19 or 20/21 only. For RTCM code differential only, you can turn on type 1 to be continuous and turn off all other message.
62 Z-Family Techncial Reference Manual
5 Coordinate Transformation This chapter describes the coordinate transformation features of your receiver. Background GPS determines the three-dimensional positions of surveyed points based on the WGS84 datum. These coordinates are either presented as geocentric cartesian coordinates (X,Y,Z) values or geodetic coordinates (latitude, longitude, ellipsoidal height). There are circumstances where it would be desirable to have positions represented in a different reference frame or format, i.e.
Table 5.1: User Coordinate Transformation Functionalities (continued) Transformation Description Datum to Grid Data projected from a geodetic system, associated with WGS-84 or a user defined datum and a specified grid system.
The generic formula used to translate and rotate from coordinate system 1 to coordinate system 2 is as follows: x y z 2 1 ε rz – ε ry x ∆x –6 = ∆y + ( 1 + m ×10 ) – ε rz 1 ε rx y ∆z ε ry – ε rx 1 z 1 where εrx = εx expressed in radians, similarly for εry and εrz. Example: Define local datum as the WGS-72 datum $PASHS,UDD, 0,6378135.0, 298.26,0,0,4.5,0,0,-0.554,0.23 $PASHS,DTM,UDD This implements the transformations listed in Table 5.2 and below. Table 5.
Internally, the receiver implements the transformation from WGS-84 to WGS-72. Figure 5.1 demonstrates the change in the coordinate systems. Figure 5.1: Rotation and Translation Between Coordinate Systems At this time, the receiver is computing geodetic coordinates in the system defined. All coordinates output by the receiver will now be in this new system. Do not forget to issue the $PASHS,DTM,UDD command after defining the transformation parameters with the $PASHS,UDD command.
Datum to Grid This transformation is used to generate coordinates in an rectangular system, based on the user’s location and mapping requirements or local standard. The user may select any projection along with any base datum for output. CAUTION Some projections and combinations of datums and projections are invalid, even if mathematically possible. The previous section described how to set up the receiver to compute geodetic coordinates (Latitude and Longitude) in the datum that you desire.
Projection Types The following graphics represent the different types of projections available for you receiver. Figure 5.2: Mercator Figure 5.
Figure 5.4: Oblique Mercator Coordinate Figure 5.
Figure 5.6: Lambert Conformal Conic Elevation Modeling In addition to the ability to compute and output geodetic and cartesian coordinates in different systems, the receiver can compute and output elevations in different systems. By default, the receiver computes and outputs ellipsoidal heights. In some messages, the geoid separation is included, computed from the internal global model, relative to WGS-84. To set the receiver to compute and output orthometric heights, use the $PASHS,HGT,GEO command.
6 Command/Response Formats This chapter details the formats and content of the serial port commands through which the receiver is controlled and monitored. These serial port commands set receiver parameters and request data and receiver status information. Use the RCS (or REMOTE.exe) software or any other standard serial communication software to send and receive messages.
The parameter type is indicated by the symbol that is a part of the syntax. The format of these parameters are as follows: Table 6.1: Command Parameter Symbols Symbol Parameter Type d Numeric integer f Numeric real c 1 character ASCII s character string m mixed parameter (integer and real) for lat/lon or time h hexadecimal digit Example 3 2.45 N OFF 3729.
Receiver Commands Receiver commands change or display various receiver operating parameters such as recording interval, antenna position, and PDOP mask. Commands may be sent through any available serial port. Set Commands The general structure of the set commands is: $PASHS,s,c where s is a 3 character command identifier, and c is one or more data parameters that will be sent to the receiver.
The format of the response message may either be in a comma deliminated format or in a free form table format, depending upon the query command, Note that not every set command has a corresponding query command. The most useful query command to check the general status of most receiver parameters is: $PASHQ,PAR Table 6.2 on page 74 lists the receiver commands alphabetically by function, and then alphabetically within each function.
Table 6.
Table 6.2: Receiver Commands Table (continued) Function Survey Command $PASHS,ANA $PASHS,ANH $PASHS,ANR $PASHS,ANT $PASHQ,ANT $PASHS,MST Tiltmeter Description Page 77 77 77 78 79 $PASHS,SIT Antenna height after survey Antenna height before survey Antenna reduction setting Set antenna offsets Query antenna offset parameters Set minimum number of satellites for kinematic survey.
ALT: Set Ellipsoid Height $PASHS,ALT,f Sets the ellipsoidal height of the antenna, where f = ±99999.999 meters. The receiver uses this data in the position calculation for 2-D position computation, and when in differential base mode. Examples: Set the ellipsoidal height of the antenna to 100.25 meters. $PASHS,ALT,100.25 Set the ellipsoidal height of the antenna to -30.1m. $PASHS,ALT,-30.1 ANA: Post-Survey Antenna Height $PASHS,ANA,f Sets the antenna height after survey, where f is from 0.
When turned off, the parameters entered via $PASHS,ANT are ignored and the position is the position of the phase center of the antenna. This implies that the base position entered should also be the one of the phase center of the base antenna. Table 6.4: ANR Message Structure Parameter Description s Reduction Mode Range ON => Antenna Reduction on ALL position messages for Autonomous, Code Differential, and RTK.
Table 6.5: Antenna Offsets Settings (continued) Parameter Description Range Unit m1 horizontal azimuth: measured from reference point to antenna phase center, with respect to the WGS84 north (dddmm.mm) 35959.99 Degrees decimal minutes f4 horizontal distance: measured from reference point to point below (above) antenna phase center. 999.9999 Meter Example: Set antenna offsets. $PASHS,ANT,1.678,0.1737,0.
BEEP: Beeper Set-up $PASHS,BEEP,s This command enables or disables the audible Beeper, where s is ON or OFF. If the beeper is disabled, it will not sound when a warning is generated. The beeper is ON by default in Z-Surveyor and FX and OFF by default in Z-Sensor. Z-Eurocard doesn’t have a beeper. The status is saved on battery back memory if $PASHS,SAV,Y has been issued afterwards. Example: Disable the beeper.
Table 6.7 on page 81 describes the parameters in the response message. Table 6.7: CLM Message Structure Parameter Significance d1 size of the data card in kilobytes *cc checksum CTS: Port Protocol Setting $PASHS,CTS,c,s This command enables or disables the RTS/CTS (handshaking) protocol for the specified port, where c is the port and s is ON or OFF. If the port is not specified (i.e., if c is not included in the command), the protocol is enabled or disabled for the port to which the command was sent.
monitor (handheld or PC). When a port is in daisy chain mode, it can only interpret the OFF command; all other characters are redirected. The OFF command discontinues the daisy chain mode. Redirection can also be bi-directional (i.e. A to B and B to A at the same time), but a 2nd command is necessary to set the other direction. Table 6.8: DSY Parameter Table Parameter Description Range c1 Source Port A...D c2 Destination Port A...D Example: Redirects A to B. Can issue from any port.
Example: Sets the epoch counter to 20. $PASHS,EPG,20 FIL,C: Close a File $PASHS,FIL,C Closes the current file in the receiver. Example: Closes the current file in the receiver. $PASHS,FIL,C FIL,D: Delete a File $PASHS,FIL,D,d Delete data file(s) from the receiver, where d is the file index number, and ranges from 0 - 99. If d is 999 then all files are deleted and the PC card is reformatted.
Example: Fix altitude to always use the entered altitude. $PASHS,FIX,1 FLS: Receiver File Information $PASHQ,FLS,d This command requests file information from the memory card, where d is the beginning file index number and can range from 0 - 99. The file index number is a sequence number where the first file has a file index = 0, the second file has a file index = 1, and continuing through to the 100th file which has a file index number of 99. The output displays files in blocks of up to 10 files.
Response: $PASHR,FLS,d1,d2,d3,n(s4,m5,d6) *cc Table 6.10: FLS Message Structure Parameter Description d1 Free memory in receiver PCMCIA card in Kbytes. d2 Total number of files currently in the receiver. d3 Number of files that match the query parameter and are displayed in the response. s4 File 4 character site name.
HDP: HDOP Mask $PASHS,HDP,d Set the value of the HDOP mask, where d is a number between 0 and 99 (default =4). Example: Set the HDOP mask to 6. $PASHS,HDP,6 INF: Set Session Information $PASHS,INF,c1,s2,s3,s4,s5,s6,f7,d8,d9,d10,d11 Sets a variety of session information parameters. Table 6.
$PASHR,INF The response message is in the form: $PASHR,INF,f1,d2,d3,d4,c5,d6,d7,s8,c9,s10,s11,s12,s13,s14,f15,d16, d17,d18,d19,f20,d21,d22,d23,d24 *cc Where Table 6.13 on page 87 outlines the response format. Table 6.13: INF Message Structure Return Parameters Description Range Data recording interval in seconds 0.
Table 6.13: INF Message Structure (continued) Return Parameters Description Range d24 Barometric pressure after data collection (millibars) *cc Checksum 0 - 9999 INI: Receiver Initialization $PASHS,INI,d1,d2,d3,d4,d5,c6 The INI command resets the receiver memory, sets the serial port baud rate to the specified rates, and/or sends the modem initialization string through the specified port. Table 6.
Table 6.16: Reset Memory Codes Reset Memory Code Action 0 No memory reset 1 Reset internal memory/battery back-up memory 2 Reset/reformat PCMCIA card 3 Reset internal memory and PCMCIA card The Reset Memory Codes 0 and 2 behave like a power cycle. Any parameters not saved with the $PASHS,SAV command are lost. Code 1 and 3 will reset all parameters to default as well as the ephemeris and almanac (i.e., creates a cold start).
Where Table 6.17 outlines the response structure. Table 6.17: ION Message Structure Type Size (Bytes) float 4 α float 4 α1 float 4 α 2. Ionspheric parameter (sec. per semicircle) float 4 α 3. Ionspheric parameter (sec. per semicircle) float 4 β 0. Ionspheric parameter (seconds) float 4 β 1. Ionspheric parameter (sec. per semicircle) float 4 β 2. Ionspheric parameter (sec. per semicircle) float 4 β 3. Ionspheric parameter (sec. per semicircle) double 8 A1.
user to select the tracking loop parameters based on the application. The receiver uses default values until another setting is selected. The user settings are saved in batterybacked memory if the $PASHS,SAV,Y command is issued afterwards and are used until a new setting is selected, or the memory is cleared. The default is 1, 2, 3. Table 6.18: LPS Message Structure Parameter Description Range d1 3rd order loop ratio 00 - 10 0- 2nd order only 1 - ratio of 0.1 (low acceleration) ..................
MDM: Set Modem Parameters $PASHS,MDM,s1,c2,d3,d4,CFG,s5,MOD,s6,NAM,s7,D2C,s8,C2D,s9 Table 6.
Example: To send all parameters for user modem. $PASHS,MDM,ON,B,4,6,CFG,ATS111=255S45=255S51=252S58=250 =1&D2&C1X12E0Q0&W\r\n,MOD,AT&F1\r\n,NAM,US-ROBOTICS, D2C,+++AT, C2D,ATO\r\n To send only mode and data to command escape string and default baud rates. $PASHS,MDM,ON,B,4,MOD,AT&F1\r\n,D2C,+++AT $PASHQ,MDM,c Query current modem parameter settings, where c is the output port and is not required to direct the response message to the current communication port.
MDM,INI: Initialize Modem Communication $PASHS,MDM,INI The $PASHS,MDM,INI command establishes communication between the modem and the receiver. This command must be run to initiate modem communication after modem parameters have been set using the $PASHS,MDM command.
Example: set *9900XY to the MET CMD field. $PASHS,MET,CMD,C,9900XY MET,INIT: Meteorological Meters Initialization $PASHS,MET,INIT,c,s Set meteorological meters initialization string. Table 6.23: MET,INIT Message Structure Parameter Description Range c Serial port connected to meteorological meters A-D s initialization string of meteorological meters excluding the starting ’*’ sign limited to 20 alphanumeric characters Example: set *9900ID to the INIT STRING_MET field.
alarm will only disappear if the user acknowledges it (press any key), not if enough satellites are tracked again. Example: Set minimum number of satellites to 5. $PASHS,MST,5 Table 6.25: MST Parameter Table Parameter d Description Range Min. number of satellites required for a kinematic survey.
OUT, TLT: Start Tiltmeter Process $PASHS,OUT,c,TLT,s Start/stop the processing of the tiltmeters. It first initializes the meters and then regularly queries them at the interval requested, where c is the port the tiltmeters is connected to and s is ON or OFF. Table 6.27: OUT,TLT Message Structure Parameters Example: Description Range c Serial port connected to the tiltmeter A-D s enable /disable the tiltmeters processing ON / OFF Start tiltmeter on port B.
Table 6.28 lists all of the above fields in alphabetic order. The description of the field is given along with the set command to modify them. Table 6.28: PAR Parameter Table Return Parameters 98 Description/Related Command Range Unit ALT Altitude of antenna $PASHS,POS or $PASHS,ALT ±0-99999.
Table 6.28: PAR Parameter Table (continued) Return Parameters Description/Related Command Range Unit PRTA, PRTB, PRTC, PRTD Output to port A/B/C/D $PASHS,NME ‘ON’, ‘OFF’ n/a PRT Port sending or receiving differential corrections $PASHS,RTC A-D n/a SAV Save parameters in the battery-backed-up memory. $PASHS,SAV Y/N n/a SVS Satellites which the receiver will attempt to acquire $PASHS,SVS Y/N n/a UNH Use unhealthy satellites for position computation.
PHE: Photogrammetry Edge (Event Marker Edge) $PASHS,PHE,c Sets the photogrammetry time tag to either the rising or falling edge of the pulse. The Event Marker receiver option (E) must be installed for this command to work. Table 6.29: PHE Parameter Table Setting parameter c Description Range direction of photogrammetry edge ‘R’ - rising (default) ‘F’ - falling Example: Set the photogrammetry edge to the falling edge.
PJT: Log Project Data $PASHS,PJT,c1s2s3s4s5s6 This command allows you to enter project data related to the station occupation. This information will appear in the S-file and in the $PASHQ,INF query. Table 6.
PMD: Position Mode $PASHS,PMD,d Set position mode for minimum number of SVs required to compute a position fix, where d = 0, 1, 2, or 3. The default is 0. Table 6.32: PMD Parameter Table Parameter Description d=0 minimum of 4 SVs needed (e.g.
POW: Battery Parameters $PASHS,POW,d1,d2,f3 The POW command allows you to enter parameters associated with the external battery. The query and response will use those parameters to compute the approximate amount of available time left on the battery. Table 6.34: POW Parameter Table Parameter Description Range d1 battery capacity in mAh 500 - 10000 d2 battery capacity in percent (percent charged) 0-100 f3 battery voltage 10.0 - 28.
PPO: Point Positioning $PASHS,PPO,c Enable/disable point positioning mode, where c is either Y (enable) or N (disable). Point positioning is an averaging algorithm that will improve the stand alone accuracy of a static point after about 4 hours. Table 6.
$PASHQ,PPS,c Query PPS parameter where c is the output port. Note that c is not required to direct the response message to the current communication port. Example: Query PPS parameters to port A. $PASHQ,PPS,A $PASHR,PPS The response is in the form: $PASHR,PPS,d1,f2,c3*cc where Table 6.38 outlines the structure: Table 6.38: PPS Response Structure Parameter Description d1 Period. Range from 0 to 60.0 f2 Offset, Range from -999.9999 to +999.
Table 6.40: Baud Rate Codes Code Baud Rate Code Baud Rate 0 300 5 9600 1 600 6 19200 2 1200 7 38400 3 2400 8 56800 4 4800 9 115200 PWR: Sleep Mode $PASHS,PWR,off Direct the receiver to immediately go into sleep mode. Once a receiver is in sleep mode, any character issued through any port will restore normal operation. Example: Put receiver into sleep mode $PASHS,PWR,OFF This command doesn’t apply to Z-Eurocard since the power supply is external to the board.
the same or another PCMCIA card is inserted into the receiver, the receiver will automatically restart data recording. The Restart command is necessary to restart data recording only if the Stop command is used, but the PCMCIA card is not actually removed. See $PASHQ,RAW command for a list of the various states this parameter can take internally. Table 6.
Table 6.42: RID Message Structure Return Parameters Description Range s3 nav firmware version 4 char string s4 Receiver options Refer to Table 1.2 on page 2. s5 boot version 4 char string *cc checksum in hex Example: Response: $PASHR,RID,UZ,30,UC00,-UE-MF-3J-,0A13*43 RNG: Data Type $PASHS,RNG,d Sets data recording mode where d is the desired data type. Table 6.
Example: Reset receiver parameters $PASHS,RST CAUTION Ensure that 110 millisecond delay occurs before a new set command is issued. RTR: Real-Time Error $PASHR,RTR This is an unsolicited response message that the receiver will send when a runtime error occurs. The response is an unsigned hex long word bitmap with the following bit assignments indicating the position computation didn’t converge. The message is in the form: $PASHR,RTR,h*cc Table 6.
the current day for session programming to operate. Use the $PASHS,SES,SET to program individual sessions. Table 6.45: SES,PAR Message Structure Setting parameter Description Range c1 Session in use Y = Yes N = No S = Sleep Mode Y or N or S d2 Session reference day 0-366 d3 Session offset (mm:ss) 0-59 This command and all the other session programming commands applies only to Z-Surveyor and Z-FX receiver.
Example: Set a session starting at 0100 that will run for 2 hours. $PASHS,SES,SET,A,Y,010000,030000,10.0,10,3,0 If sleep mode is enabled, the receiver will automatically power on 2 minute prior to session time to ensure all available satellites are tracked by the time recording starts. This command applies only to the Z-surveyor and Z-FX receivers. $PASHQ,SES,c Query session programming parameters, where c is the optional output serial port.
Table 6.47: SES Message Structure Return Parameters Description Range 7th Column Session minimum SVs 1-9 8th Column Session data type 0, 2, or 4 INUSE Session use Y or N or S REF Session reference day 0-366 OFFSET Session time offset (minutes, seconds) mm:ss TODAY Date of the year 0-366 This command applies only to the Z-surveyor and Z-FX receivers SID: Serial Number $PASHQ,SID,c Query receiver serial number and firmware timestamp, where c is the optional output port.
SPD: Serial Port Baud Rate $PASHS,SPD,c1,d2 Set the baud rate of the receiver serial port c1, where c1 is port A, B, C, or D and d2 is a number between 0 and 9 specifying the baud rate as shown in Table 6.48 on page 113. Default is 9600 baud. Table 6.
The return message is a free form format. A typical response is: TIME: 03:24:24 UTC LOCKED: 23 22 17 06 30 10 26 CA S/N 50 46 54 53 43 43 44 P1 S/N 48 00 52 51 36 00 00 P2 S/N 44 00 48 47 38 00 00 Table 6.
TLT : Tiltmeter Set-up $PASHQ, TLT,c Query tiltmeter setup, where c is the optional output port and is not required to direct the response to the current port.
Example: set *9900ID to the INIT STRING_ TLT field. $PASHS,TLT,INIT,A,9900ID TLT,INTVL: Tiltmeter Interval $PASHS, TLT,INTVL,c,d Set the interval for the query of the tiltmeters. Table 6.
TST:Output RTK Latency $PASHS,TST,d Enable/Disable the output of the RTK (fast CPD) latency as decimal part of the age of correction in the GGA message. There is no query to check this setting since it is visible in the GGA message (age of correction is an integer number when disabled). This setting will revert back to default at power on unless saved in battery-backed memory through the $PASHS,SAV,Y command (issued after setting the desired mode). Table 6.
Example: Set VDOP to 6 $PASHS,VDP,6 WAK: Warning Acknowledgment $PASHS,WAK This command acknowledges a warning condition (status displayed by WARN will go from CURRENT to PENDING) and will stop the receiver beep that accompanies a warning (if the beep is set to ON). WARN: Warning Messages $PASHQ,WARN,c This queries the receiver for any warning messages, where c is the optional output port.
Table 6.56 contains the possible warnings the receiver may issue. Table 6.56: Receiver Warning Messages Warning Definition Action Int. Battery Error : SMBus The SMBus controller (for the internal battery communication) is not working Remove battery and reinsert it. If problem persists, insert a different battery. If problem still persists, contact customer support. Int. Battery Error : Access Can’t access the internal battery Remove battery and reinsert it.
Table 6.56: Receiver Warning Messages (continued) Warning 120 Definition Action †Data Card Error : Access Can’t read or write to the PC card Power cycle the receiver. If problem persists, replace the PC card. †Data Card Error : Update Can’t update the FAT (file access table) Power cycle the receiver. If problem persists, replace the PC card. †Data Card Error : Create Can’t create the files for new session so we can’t record data Power cycle the receiver. If problem persists, replace the PC card.
Table 6.56: Receiver Warning Messages (continued) Warning Definition Action The position entered Enter correct base position. in the base receiver for RTCM code operation is not correct (too far from computed position) †‡Not Enough Satellites Tracking less than the minimum number of satellites required for kinematic survey The kinematic survey must be reinitialized on last point.
Table 6.56: Receiver Warning Messages (continued) Warning Definition Action High Receiver Temperature Inside receiver temperature > 80 deg Celsius: the receiver will turn off automatically at 82 deg Celsius (this message might be seen when the external ambient temperature is >55 degrees Celsius Cover the receiver from the sun. Increase air flow around receiver.
Raw Data Commands The raw data commands cover all query and set commands related to measurement, ephemeris, and almanac data. Set Commands There is only one set command that controls the continuous output of all raw data messages; the $PASHS,OUT command. The $PASHS,OUT command allows you to enable or disable the output of one or more raw data messages simultaneously as well as change the format (ASCII or Binary) of the messages types where the format is an option.
Query Commands The query commands will output a single raw data message type once. The general format of the query commands is: $PASHQ,s,c where s is the 3 character string that denotes the raw data message type, and c is the serial port to which the message will be output. The serial port field is optional. If the query is sent with the port field left empty, then the response will be sent to the current port. If the port field contains a valid port (A-D), then the response will be output to that port.
Table 6.59 on page 125 list all the raw data commands. A complete description of each command can be found following the table. Table 6.
Table 6.60 outlines the response structure. Table 6.60: CBN Message Structure (ASCII Format) Parameter 126 Description Range m1 Receiver time UTC (hhmmss.ss) 0 - 235959.99 s2 Four character site identification d3 Number of satellites used in position computation. 0 -12 f4 PDOP 0 - 999.9 m5 Latitude in degrees and decimal minutes ddmm.mmmmmmm 0 - 90.0 c6 Latitude direction ‘N’/’S’ m7 Longitude in degrees and decimal minutes ddmm.mmmmmmm 0 - 180° 0 - 59.
Below is a description of solution type flag: Table 6.
Table 6.62: CBN Message Structure (Binary Format) (continued) Data Type Symbol Range char Num_Svs 0 - 12 unsigned short PDOP 0 - 100 double Lat_N sign deg frac. double Lon_E deg frac. double EH float Resolution Compress Num. Bits Description 4 Number of satellites used in CPD position computation 0.1 10 PDOP ± 0-90° 0-1 e-9 deg (e-4 m) 1 7 30 Rover position latitude north 0-360° 0-1 e-9 deg (e-4 m) 9 30 Rover position longitude east sign 1 data: -1km - 100km 0.
Table 6.62: CBN Message Structure (Binary Format) (continued) Data Type Symbol Range Resolution Compress Num. Bits Description float Vel_E sign ± data 1000 m/s 0.001 m/s 1 20 Velocity of East direction float Vel_N sign ± data 1000 m/s 0.001 m/s 1 20 Velocity of North direction float Vel_U sign data 0.001 m/s 1 19 Velocity of Upper direction float Sigma_VE 0 -16.0 m/s 0.001 m/s 14 Standard Deviation of East Velocity float Sigma_VN 0 - 16.0 m/s 0.
Table 6.
Table 6.64: RPC Message Structure Parameter Type num. of bytes data length unsigned short 2 packed data unsigned char[] data length ChkSum unsigned short 2 Description number of bytes in part see below Accumulative unsigned short summation of the , after before Parameter: Table 6.65: RPC Packed Parameter Descriptions Data Type Symbol Range 0 - 604800000 Resolution Compress Num.
Table 6.65: RPC Packed Parameter Descriptions (continued) Data Type Symbol Range Resolution Compress Num. Bits Description long PH_I 1 28 Integer part of the carrier phase measurement in cycles double PH_F 15.0e-4 11 Fractional part of the carrier phase measurement in units of 5e-4 cycles. Multiply this number by 5e-4 to get fractional carrier phase in cycles. Whole carrier phase measurement = PH_I + PH_F*5.
Example: Query for raw ephemeris for all available satellites. $PASHQ,EPB Query ephemeris data for PRN 25. $PASHQ,EPB,25 $PASHR,EPB The response is the broadcast ephemeris data. See the ICD-GPS-200 for definition of the Parameters. Each subframe word is right-justified in a 32-bit long integer. The response is in the form: $PASHR,EPB,d, This message only exists in a binary format, if ASCII format is requested (default) only the header will be sent ($PASHR,EPB).
Table 6.
Where Table 6.68 on page 135 outlines the measurement structure. The checksum is computed after the MPC header, and includes the last comma. Table 6.68: MPC Measurement Structure (Binary Format) Type Size Contents unsigned short 2 sequence tag (unit: 50 ms) modulo 30 minutes unsigned char 1 number of remaining struct to be sent for current epoch. unsigned char 1 satellite PRN number. unsigned char 1 satellite elevation angle (degree).
The MBN response message in ASCII is in the form: $PASHR,MPC,d1,d2,d3,d4,d5,d6,d7,d8,d9,d10,d11,f12,f13,f14,f15, d16,d17,d18,d19,d20,d21,f22,f23,f24,f25,d26,d27,d28,d29,d30,d31, f32,f33,f34,f35,d36,ccc Table 6.69 on page 136 provides details on the individual Parameters: Table 6.69: MPC Message Structure (ASCII Format) Parameter Significance Units d1 Sequence tag. This is the time tag used to associate all structures with one epoch. It is in units of 50 ms and modulo 30 minutes.
Table 6.69: MPC Message Structure (ASCII Format) (continued) Parameter Significance d19 5 for backward compatibility d20 Signal to noise indicator d21 spare f22 Units Range 5 dB Hz 30-60 Full carrier phase cycles 0-999999999.999 f23 Code transmit time ms 0-99.9999999 f24 Doppler measurement 10 (-4) Hz ±99999.99999 f25 Range smoothing correction. Raw range minus smoothed range meters 0-99.99 d26 Range smoothing quality 0-200 PL2 Code Data Block d27 Warning flag (seeTable 6.
Table 6.70: Warning Flag Settings Description of parameter d7 Bits Index 1 2 Combination of bit 1 and bit 2 0 0 1 0 1 0 same as 22 in good/bad flag same as 24 in good/bad flag same as 23 in good/bad flag 3 carrier phase questionable 4 code phase (range) questionable 5 range not precise (code phase loop not settled) 6 Z tracking mode 7 possible cycle slip 8 loss of lock since last epoch Table 6.
To disable raw data output, send the $PASHS,OUT, command without any data format strings. Table 6.72: OUT Message Structure Parameter c1 s2, s3 f4 Description Range serial port A- D raw data type string, may have one or more delimited by commas MBN, PBN, SNV, CBN, DBN, EPB, SAL ASCII or binary format ASC or BIN Examples: Enable MBN, PBN, and SNV message in binary format on port C.
Table 6.73: PBN Message Structure (ASCII Format) (continued) Parameters Description Range m5 Latitude in degrees and decimal minutes (ddmm.mmmmmm) Positive north. ±90 m6 Longitude in degrees and decimal minutes (dddmm.mmmmmm) Positive east. ±180 f7 Altitude (meters) ±99999.999 f8 Velocity in ECEF-X (m/sec). ±999.99 f9 Velocity in ECEF-Y (m/sec). ±999.99 f10 Velocity in ECEF-Z (m/sec). ±999.99 d11 Number of satellites used for position computation.
Table 6.74: PBN Message Structure (Binary Format) (continued) Parameter Bytes Significance float navtdot 4 Clock drift unsigned short pdop 2 PDOP unsigned short chksum 2 checksum Total bytes 56 Units m/sec RAW: Query Raw Data Parameter $PASHQ,RAW This query will display the settings of all parameters related to raw data. Example: $PASHQ,RAW Return Message: RCI:020.0 MSV:03 ELM:10 REC:Y MST:0 ANH:00.0000 ANA:00.
Table 6.75: RAW Message Structure (continued) Return Parameters Description REC Data recording to PCMCIA card ‘Y’ = Yes ‘N’ = No (does not close file) ‘E’ = Error (recording is Y but can’t write to PC card at this point) ‘S’ = Stop recording (closes file) ‘F’ = Bad FAT ‘D’ = Download in progress MST Minimum satellites required for kinematic survey 0, 4 - 9 N/A 0 ANH Antenna height 0.0000 to 64.0000 meter 0.0 ANA Antenna height after survey 0.0000 to 64.0000 meter 0.
$PASHR,ALM The response is a binary message in the form:. $PASHR,ALM,(almanac structure) This message only exists in binary format. If ASCII format is requested (default), only the header will be sent ($PASHR, ALM). The almanac structure is defined in Table 6.76. Table 6.76: ALM Message Structure Type Size short 2 (Satellite PRN -1) short 2 Health. see ICD-200 for description float 4 e. Eccentricity long 4 toe. Reference time for orbit (sec) float 4 I0.
SNV: Ephemeris Data $PASHQ,SNV,c Request ephemeris data from receiver, where c is either the optional output serial or the specific PRN number. If either the port is specified, or if this field is left blank, the ephemeris structures for all available SVs will be output. Example: Send out SNAV data for all available SVs to the current port.
Table 6.77: SNV Message Structure (continued) Type Size long 4 toe. Reference time for orbit (sec). float 4 Cic. Harmonic correction term (radians). float 4 Crc. Harmonic correction term (meters). float 4 Cis. Harmonic correction term (radians). float 4 Crs. Harmonic correction term (meters). float 4 Cuc. Harmonic correction term (radians). float 4 Cus. Harmonic correction term (radians). double 8 (OMEGA)0. Lon of Asc. node (semi-circles). double 8 ω double 8 I0.
NMEA Message Commands The NMEA message commands control all query and set commands related to NMEA format messages and miscellaneous messages in a NMEA style format. All standard NMEA message are a string of ASCII characters delimited by commas, in compliance with NMEA 0183 Standards version 2.1. All non-standard messages are a string of ASCII characters delimited by commas in the Ashtech proprietary format. Any combination of these messages can be output through different ports at the same time.
Query Commands The general structure of the NMEA query commands is: $PASHQ,s,c where s is one of the 3 character NMEA strings and c is the serial port to which response message should be sent (A, B, C or D). The serial port field is optional. If a port is not included, the receiver will send the response to the current port. Unlike the set commands, the query command will initiate a single response message.
Table 6.
$GPALM There will be one response message for each satellite in the GPS constellation. The response to the set or query command is in the form: $GPALM,d1,d2,d3,d4,h5,h6,h7,h8,h9,h10,h11,h12,h13,h14, h15*cc Table 6.79: ALM Response Message Parameters Description Range d1 Total number of messages 01 -32 d2 Number of this message 01 -32 d3 Satellite PRN number 01 - 32 d4 GPS week 4 digits h5 SV health (In ASCII Hex) 2 bytes h6 e. Eccentricity (In ASCII Hex) 4 bytes h7 toe.
Example: Query: $PASHQ,ALM Response: $GPALM,26,01,01,0899,00,1E8C,24,080B,FD49,A10D58,EB4562,BFE F85,227A5B,011,000*0B Table 6.
$PASHQ,DAL,c Query decimal almanac where c is the optional output serial port. Example: $PASHQ,DAL $PASHR,DAL There will be one response message for each satellite in the GPS constellation. The response message is in the form: $GPDAL,d1,d2,f3,d4,f5,f6,f7,f8,f9,f10,f11,f12,d13*cc Table 6.81: DAL Message Structure Parameters Description Range d1 Satellite PRN number 1 - 32 d2 Satellite health 0 - 255 f3 e. Eccentricity ±9.
Example: Query: $PASHQ,DAL Response: $PASHR,DAL,01,00,3.7240982E03,061440,3.0392534E01,-2.5465852E-09,5.1536646E03,1.6172159E-01,-5.0029719E01,2.7568674E-01,1.6212463E-05,0.0000000E00,0899*51 Table 6.82: Typical DAL Message Item $PASHR,DAL Significance Header 01 Satellite PRN Number 00 Satellite Health 3.7240982E03 061440 Eccentricity Reference Time for orbit 3.0392534E-01 Inclination angle -2.5465852E-09 Rate of right ascension 5.1536646E03 Square root of semi-major axis -1.
Example: Send GDC message to the current port. $PASHQ,GDC $PASHR,GDC This message outputs the current position in the Grid Coordinate system selected by the user. The response message is in the form: $PASHR,GDC,m1,s2,f3,f4,d5,d6,f7,f8,M,f9,M,d10,s11,s12*cc Table 6.83: GDC Message Structure Parameters Description Range UTC of position in hours, minutes, and decimal seconds (hhmmss.ss) 0—235959.
Example: $PASHR,GDC,015151.00,EMER,588757.623,4136720.056,2,04,03.8,00 012.123,M,-031.711,M,14,1010,W84*2A Table 6.84: Typical GDC Response Message Item Significance 015151.00 UTM time EMER Equatorial Mercator map projection 588757.623 User Grid easting coordinate (x) 4136720.056 User Grid northing coordinate (y) 2 RTCM differential position 04 Number of SVs used to compute position 03.8 HDOP 00012.123 Altitude of position M Altitude units (M=meters) -031.
Example: $PASHQ,GGA $GPGGA The response message is in the form: $GPGGA,m1,m2,c3,m4,c5,d6,d7,f8,f9,M,f10,M,f11,d12*cc Table 6.85: GGA Message Structure Parameters Description Range Current UTC time of position fix in hours, minutes, and seconds (hhmmss.ss) 00-235959.90 m2 Latitude component of position in degrees and decimal minutes (ddmm.mmmmmm) 0-90 c3 Direction of latitude N= North, S= South N/S m4 Longitudinal component of position in degrees and decimal minutes (dddmm.
Example: Query: $PASHQ,GGA Response: $GPGGA,015454.00,3723.285132,N,12202.238512,W,2,04,03.8,00012.1 23,M,-032.121,M,014,0000*75 Table 6.86: Typical GGA Message Item Significance $GPGGA Header 015454.00 UTC time 3723.285132 N 12202.238512 Latitude (ddmm.mmmmmm) North Latitude Longitude (dddmm.mmmmmm) W West longitude 2 RTCM differential position 04 Number of satellites used in position 03.8 00012.123 M -032.
$PASHQ,GLL,c Query where c is the optional output serial port. Example: $PASHQ,GLL $GPGLL The response message is in the form: Format: $GPGLL,m1,c2,m3,c4,m5,c6*cc Table 6.87: GLL Message Structure Parameters Description Range m1 Position latitude in degrees and decimal minutes (ddmm.mmmmmm) 0 - 90° c2 Direction of latitude N = North, S = South N/S m3 Position longitude in degrees and decimal minutes (dddmm.
Table 6.88: Typical GLL Message (continued) Item Significance 202556.00 UTC time of position A Status valid *12 checksum GRS: Satellite Range Residuals $PASHS,NME,GRS,c,s This command enables/disables the NMEA satellite range residual response message to port c, where c is A, B, C, or D, and s is ON or OFF. If only four SVs are used in the position solution, residuals are not computed and GRS outputs zeroes in the residual fields. With 3 or less SVs, the message is not output.
Table 6.89: GRS Message Structure (continued) Parameters Description f3 Range residuals for satellite used in position computation. The order of the residuals matches the order of the satellites in the GSV message. *cc checksum Range ± 999.999 The range residuals are re-computed after the GGA position is computed, therefore the mode is always 1. Example: Query: $PASHQ,GRS Response: $GPGRS,203227.50,1,-007.916,051.921,-048.804,-026.612, -002.717,021.150*63 Table 6.
Example: Enable GSA message on port B $PASHS,NME,GSA,B,ON $PASHQ,GSA,c Query DOP and active satellites where c is the optional output serial port. Example: Query GSA message to the current ports. $PASHQ,GSA $GPGSA The response message is in the form: $GPGSA,c1,d1,d2,d3,d4,d5,d6,d7,d8,d9,d10,d11,d12,d13,f1, f2,f3*cc Table 6.
Table 6.92: Typical GSA Message Item Significance empty field Satellite in channel 3 04 Satellite in channel 4 27 Satellite in channel 5 26 Satellite in channel 6 07 Satellite in channel 7 empty field Satellite in channel 8 empty field Satellite in channel 9 empty field Satellite in channel 10 empty field Satellite in channel 11 09 Satellite in channel 12 3.2 PDOP 1.4 HDOP 2.
where n is equal to the number of locked satellites. Table 6.93: GSN Message Structure Field Significance Range d1 Number of SVs locked 0 - 12 d2 PRN number 1 - 32 f3 Signal Strength in DB Hz 30.0 - 60.0 d4 999 to end the message or RTCM age of corrections (if available) 999 *cc Checksum Example: Query: $PASHQ,GSN Response: $GPGSN,04,02,46.5,04,48.4,07,50.8,09,51.2,999*7C Table 6.94 on page 162 describes each item in a typical GSN message. Table 6.
GSV: Satellites in View Message $PASHS,NME,GSV,c,s This command enables/disables the satellites-in-view message to send out of serial port, where c is port A, B, C, or D, and s is ON or OFF. Example: Output GSV message on port A $PASHS,NME,GSV,A,ON $PASHQ,GSV,c Query satellites in view where c is the optional output serial port. Example: Query the GSV message on port A. $PASHQ,GSV,A $GPGSV The response message is in the form: $GPGSV,d1,d2,d3,n(d4,d5,d6,f7)*cc Where n is maximum 4.
where each item is as described in Table 6.96 on page 164. Table 6.96: Typical GSV Message Item Significance 2 Total number of messages 1..3 1 message number 1..3 8 number of SVs in view 1..12 16 PRN of first satellite 1..32 23 elevation of first satellite 0..90 293 azimuth of first satellite 0...359 50.3 signal-to-noise of first satellite 19 PRN of second satellite 63 elevation of second satellite 050 azimuth of second satellite 52.
$PASHQ,GXP,c Query horizontal position where c is the optional output serial port. Example: $PASHQ,GXP,A $GPGXP The response message is in the form: $GPGXP,m1,m2,c3,m4,c5*cc Table 6.97: GXP Message Structure Parameters Description Range m1 UTC of fix in hours, minutes and seconds (hhmmss.ss) 00-235959.90 m2 Latitude in degrees and decimal minutes (ddmm.mmmmmm) 0 - 90.00 c3 Direction of latitude N = North, S = South N/S m4 Longitude in degrees and decimal minutes (dddmm.
Table 6.98: Typical GXP Message (continued) Item W *7A Significance West Longitude checksum MSG: Base Station Message $PASHS,NME,MSG,c,s This command enables/disables the message containing RTCM reference (base) station message types 1, 2, 3, 6, and 16, 18, 19 where c is the output port, A, B, C, or D, and s is ON or OFF. Unless the unit is sending or receiving differential corrections, this command is ignored.
Message type 18 format: $GPMSG,d1,d2,f3,d4,d5,d6,m7,n(d8,d9,d10,d11,d12,d13,d14,d15)*cc Message type 19 format: $GPMSG,d1,d2,f3,d4,d5,d6,m7,n(d8,d9,d10,d11,d12,d13,d14,f15)*cc Message type 20 format: $GPMSG,d1,d2,f3,d4,d5,d6,m7,n(d8,d9,d10,d11,d12,d13,d14,d15)*cc Message type 21 format: $GPMSG,d1,d2,f3,d4,d5,d6,m7,n(d8,d9,d10,d11,d12,d13,d14,f15)*cc Common part of message 1,2,3,6,16,18,19,20 and 21. Table 6.
Table 6.100: Remainder of Type 1 Parameters Description Range d12 Issue of data ephemeris (IODE) *cc checksum 0-999 Remaining message for type 2 Table 6.101: Remainder of Type 2 Message Parameters Description Range d8 User differential range error (UDRE) 0-9 d9 Satellite PRN Number 1-32 f10 Delta Pseudo range correction (Delta PRC) in meters ±99.99 f11 Delta Range rate correction (Delta RRC) in meters/sec ±9.
Remaining for Message type 18/20 (RTK carrier phase corrections) size for type 18/20: total number of svs for L1 and L2 frequency +2*(10 byte freq+GNSS) + 3 byte chksum + 2 byte Table 6.104: Remainder of Type 18 and 20 Messages Parameters Range Description d8 L1 or L2 frequency 00...01 d9 GPS time of measurement 0..599999 [usec] d10 half/full L2 wavelength indicator 0 - full, 1 - half d11 CA code /P code indicator 0 - CA, 1 -P d12 SV prn 1..32 d13 data quality 0..
Remaining message for type 19 (uncorrected pseudorange measurements) and 21 (RTK pseudorange correction). size for type 19 /21: total number of svs for L1 and L2 frequency + 2*(13 byte Freq+sm+GNSS) + 3 byte chksum + 2 byte Table 6.105: Remainder of Type 19 and 21 Messages Parameters Description Range d8 L1 or L2 frequency 00...01 d9 Smoothing interval 00 - 0..1 min 01 - 1..5 min 10 - 5..15 min 11 - indefinite d10 GPS time of measurement 0..
PER: Set NMEA Send Interval $PASHS,NME,PER,f Set send interval of the NMEA response messages in seconds, where f is a value between 0.1 and 999. Values between 0.1 and 1 can be set at 0.1 second increments. Values between 1 and 999 can be set at 1 second intervals. Value 0.7 is not available. Example: Output NMEA messages every 5 seconds. $PASHS,NME,PER,5 If the fast data option (F) is installed, then PER can be set to 0.1 (10 Hz). If the fast data option is not installed, then PER can be set to 0.
Table 6.106: POS Message Structure (continued) Parameters Description Range m3 Current UTC time of position fix (hhmmss.ss) 00-235959.90 m4 Latitude component of position in degrees and decimal minutes (ddmm.mmmmmm) 0 - 90 c5 Latitude sector, N = North, S = South N/S m6 Longitude component of position in degrees and decimal minutes (dddmm.mmmmmm) 0 - 180 c7 Longitude sector E = East, W = West W/E f8 Altitude above whatever datum has been selected in meters.
Table 6.107 on page 173 describes each item in a typical POS message. Table 6.107: Typical POS Message Item $PASHR,POS Significance Header 0 Raw Position 06 Number of SVs used in position fix 214619.50 3722.385158 N 121159.833768 UTC time of position fix Latitude North Latitude Longitude W West Longitude 00043.110 Altitude (meters) empty field reserved 331.0 Course over ground (degrees) 000.7 Speed over ground (knots) 000.0 Vertical velocity (dm/sec) 02.7 PDOP 01.2 HDOP 02.
Example: Enable PTT message on port A $PASHS,NME,PTT,A,ON $PASHQ,PTT,c Query the time tag of the next PPS pulse, where c is the optional output port. If c is not specified, the reply is sent to the port on which the query was made. The response will be sent out once, right after the next PPS pulse is generated, and contains the GPS time at which the PPS pulse was sent, including the offset if an offset was set when the PPS pulse was enabled.
$PASHQ,RMC,c Query recommended minumum GPS/transit message, where c is the optional output port. $GPRMC The return message is in the form: $GPRMC,m1,c2,m3,c4,m5,c6,f7,f8,d9,f10,c11*cc Table 3.6 outlines the response structure. Table 6.110: RMC Message Structure Parameter Description Range m1 UTC time of the position fix (hhmmss.ss) 000000.00 - 235959.90 c2 Status A = Data Valid V = Navigation Receiver Warning m3 Latitude (ddmm.mmmmmm) 0000.000000 8959.
Table 6.111: RMC Response Structure Parameter 213357.20 A 3722.410857 N 12159.773686 W Description UTC time of the position fix (hhmmss.ss) Valid position Latitude ddmm.mmmmmm North Latitude Longitude dddmm.mmmmmm West Longitude 000.3 Speed over ground, knots 102.4 Course Over Ground, degrees True 290498 15.
where n = number of satellites used to compute a position Table 6.112: RRE Message Structure Parameters Description Range Units d1 Number of satellites used to compute position 3 - 12 n/a d2 Satellite number (PRN Number) 1 - 32 n/a f3 Range residual ± 999.9 meter f4 RMS Horizontal position error 0 - 9999.9 meter f5 RMS Vertical position error 0 - 9999.9 meter *cc Checksum Example: Query: $PASHQ,RRE Response: $GPRRE,04,23,8.4,28,-9.2,11,-2.2,17,3.2,34.4,49.
SAT: Satellite Status $PASHS,NME,SAT,c,s This command enables/disables the satellite status message to port c, where c is A, B, C, or D, and s is ON or OFF. Example: Enable SAT message on port B $PASHS,NME,SAT,B,ON $PASHQ,SAT,c Query satellite status where c is the optional output serial port. Example: Send SAT message to port D $PASHQ,SAT,D $PASHR,SAT The response message is in the form: $PASHR,SAT,d1,n(d2,d3,d4,f5,c)*cc where n = the number of SVs tracked. Table 6.
Table 6.115 on page 179 describes each item in a typical SAT response message. Table 6.115: Typical SAT Message Item $PASHR,SAT Significance Header 04 Number of SVs locked 03 PRN number of the first SV 103 Azimuth of the first SV in degrees 56 Elevation of the first SV in degrees 50.5 Signal strength of the first SV U SV used in position computation 23 PRN number of the second SV 225 Azimuth of the second SV in degrees 61 Elevation of the second SV in degrees 52.
when the pulse was received. This message is not output unless an event pulse is being input through the appropriate pin of port B and the event marker option (E) is available in the receiver. This message is therefore independent of the NMEA period (can be output faster or slower than the NMEA period depending on the period of the event). Example: Enable TTT message on port A $PASHS,NME,TTT,A,ON There is no query command for TTT.
$PASHR,UTM The response message is in the form: $PSHR,UTM,m1,m2,f3,f4,d5,d6,f7,f8,M,f9,M,d10,s11*cc Table 6.117: UTM Message Structure Parameters Description Range m1 UTC of position in hours, minutes, and decimal seconds (hhmmss.ss) 0 - 235959.90 m2 Zone number for coordinates Zone letter for coordinates (N = north, S = south) 1-60, 99 ‘N’, ‘S’ f3 East UTM coordinate (meters) ±9999999.999 f4 North UTM coordinate (meters) ±9999999.999 d5 Position indicator.
Example: Query: $PASHQ,UTM Response: $PASHR,UTM,015454.00,10S,588757.623,4136720.056,2,04,03.8,0001 2.123,M,-031.711,M,014,1010*3A Table 6.118: Typical UTM Response Message Item Significance 015454.00 UTC time 10S UTM zone 588757.623 UTM easting coordinate 4136720.056 UTM northing coordinate 2 RTCM code differential position 04 Number of SVs used to compute position 03.8 HDOP 00012.123 altitude M -031.
Example: Send VTG message to port C $PASHQ,VTG,C $GPVTG The response message is in the form: $GPVTG,f1,T,f2,M,f3,N,f4,K*cc Table 6.119: VTG Message Structure Parameters Description f1 COG (Course Over Ground) true north T COG orientation (T = true north) f2 COG magnetic north M COG orientation (M = magnetic north) f3 SOG (Speed Over Ground) N SOG units (N = knots) f4 SOG (Speed Over Ground) K SOG units (K = Km/hr) *cc Range 0 - 359.99 T 0 - 359.99 M 0 - 999.99 N 0 - 999.
Table 6.120: Typical VTG Message (continued) Item 001.61 K *46 Significance Speed over ground (SOG) in km/hr SOG units (K=km/hr) checksum XDR: Transducer Measurements $PASHS,NME,XDR,c,s Enable/disable the transducer measurements message, where c is the output port, and s is ON or OFF.
Table 6.121: XDR Message Structure Parameter Description Range c1 Transducer type A - Angular deplacement C - Temperature D - Linear displacement F - Frequency G - Generic H - Humidity I - current N - Force P - Pressure R - flow rate S - Switch or valve T - Tachometer U - Voltage V - Volume f2 Transducer value +/- x.
$PASHQ,ZDA,c Query time and date, where c is the optional output port and is not required to direct the response to the current port. Example: Send query of ZDA message on port A $PASHQ,ZDA,A $GPZDA The response message is in the form: $GPZDA,m1,d2,d3,d4,d5,d6*cc Table 6.122: ZDA Message Structure Parameter Description m1 UTC time (hhmmss.
RTCM Response Message Commands The RTCM commands allow you to control and monitor RTCM real-time differential operations. The RTCM commands are only available if the differential options are installed in the receiver. If the Base Station option (B) is installed, then only the base parameter and general parameter commands are accessible. If the Remote option (U) is installed, then only the remote parameter and general parameter commands are available.
Table 6.124 on page 188 lists the RTCM commands. Table 6.
Table 6.125 on page 189 describes the parameters. Table 6.125: RTC Response Parameters Return Parameters Description Range Default STATUS SYNC status that denotes sync to last received RTCM message between Base and Remote stations. (Remote only) Set to “ “ if no corrections received for “max age”. ‘*’ - in sync TYPE RTCM message type being sent (Base) or received (Remote). Type 9 applies only for remote.
Table 6.125: RTC Response Parameters (continued) Return Parameters Description Range Default QAF Sets the criteria to be applied when evaluating the quality of communication between Base and Remote. (Remote only) 0 - 999 100 SEQ Check for sequential received message number for the message to be accepted. (Remote only) N, Y N TYP RTCM message type that receiver will generate.
BAS: Enable Base Station $PASHS,RTC,BAS,c Set the receiver to operate as an RTCM differential base station, where c is the differential port and can be set to port A, B, C or D. Example: Set to differential base mode using port B $PASHS,RTC,BAS,B EOT: End of Transmission $PASHS,RTC,EOT,s Control which characters to transmit at the end of each RTCM message, where s is the end of message parameter. Default is ‘CRLF’. Table 6.
Example: Set maximum age to 30 seconds $PASHS,RTC,MAX,30 MSG: Define Message $PASHS,RTC,MSG,s Define RTCM type 16 message up to 90 characters long that will be sent from the base to the remote. $PASHS,RTC,MSG,s is used only at the base station and only if message type 16 is enabled. Example: Define RTCM message “This is a test message” $PASHS,RTC,MSG,This is a test message OFF: Disable RTCM $PASHS,RTC,OFF Disables base or remote differential mode.
Example: Set receiver as differential remote using port B $PASHS,RTC,REM,B SEQ: Check Sequence Number $PASHS,RTC,SEQ,c Checks sequence number of received messages and, if sequential, accept corrections; if not, don’t use correction, where c is Y (check) or N (do not check). Default is N. $PASHS,RTC,SEQ is used only in REMOTE mode. Valid only at beginning of differential operation. After two sequential RTCM corrections have been received, differential operation begins.
STH: Station Health $PASHS,RTC,STH,d Set the health of the base station, where d is any value between 0 and 7. $PASHS,RTC,STH is used only in BASE mode. Default is 0. Table 6.128 on page 194 defines the codes for the station health: Table 6.128: RTC,STH Health of Base Station Code Health Indication 7 Base station not working. 6 Base station transmission not monitored. 5 Specified by service provider/UDRE scale factor = 0.1 4 Specified by service provider/UDRE scale factor = 0.
TYP: Message Type $PASHS,RTC,TYP,d1,d2 Enables the type of message to be sent by the base station and the period at which it will be sent, where d1 is the type and d2 is the period. $PASHS,RTC,TYP is used only in BASE mode. Table 6.129 on page 195 lists the message types available and the period range setting. The default is type 1 set to 99, and type 6 is ON. Table 6.
CPD Commands The CPD commands allow you to control and monitor CPD (Carrier Phase Differential) operations. The commands are either general parameter or query commands, base set commands or rover set commands. The base set commands are only available if the CPD base option (K) is installed and the rover set commands are only available if the CPD Rover option (J) is installed in the receiver. In addition, using the base to output RTCM type 18/19 or 20/21 require the B option (RTCM Diff.
will output a CPD status message to the current port. The query: $PASHQ,CPD,C will output a CPD status message to port C. To use RTCM type 18/19 or 20/21, $PASHS,RTC commands are also used. (See “RTCM Response Message Commands” on page 187). Table 6.
CPD: RTK Status $PASHQ,CPD,c This is the general CPD query command where c is the optional serial port. Use this query to monitor CPD settings and status. Example: Query CPD parameters $PASHQ,CPD The response message is in free form format. A typical response appears as follows: STATUS: VERSION: PNAV_0A22 MODE:DISABLED BASE STAT: 00000 PRN: AGE: 0000ms RCVD CORD: 000 sec AMBIGUITY: N/A RCV INTVL: 01.0 sec Dlf: 00000ms Tf:00000 ms DLc:00000 ms Tc:00000 ms SETUP: DBEN PER:001.
Table 6.
Table 6.131: CPD Status Message Structure (continued) Parameter Description Range Default AUT Auto-differential mode. If Y, rover will output code differential position if available or stand-alone, if not, once the MAX AGE has been received.
Since this is only valid when using a base position entered at the rover, the user must first set $PASHS,CPD,UBP,O before entering $PASHS,CPD,ANT. Table 6.133: CPD,ANT Parameter Table Parameter Description Range Units f1 Antenna height (measured from the point to the antenna edge). (Survey mark to edge of antenna) 0 - 64.000 meter f2 Antenna radius (from antenna edge to antenna phase center) 0-9.9999 meter f3 Vertical offset (phase center to ground plane) 0 - 99.
DLK: Data Link Status $PASHQ,CPD,DLK,c This command queries the data link status message, where c is the optional output port. If the port is not specified, the message is output to the port from which this command was received Example: Query the data link status message to port A. $PASHQ,CPD,DLK,A $PASHR,CPD,DLK This response message is different for base and rover receiver.
Table 6.
Table 6.136: CPD,DLK Response Message Example - Rover Station Field 024 100.00 0405 + *44 Significance BPS message age Percentage of good DBEN message reception DBEN message age Data is in the communication port checksum From the Base station: $PASHR,CPD,DLK,BAS,02,05,02+,03+,10+,18+,19P,,PASH*12 Table 6.
Example: Set rover dynamics to aircraft dynamics $PASHS,CPD,DYN,4, Table 6.138: CPD,DYN Parameter Table Parameter d1 Description Dynamic. One of the following values: 0 -- Static (antenna on tripod) 1 -- Quasi-static (antenna on manual pole) 2 -- Walking (default) 3 -- Automobile 4 -- Aircraft 5 -- Ship ENT: Use Current Position $PASHS,CPD,ENT This command sets the current raw position as the BASE position.
FST: Fast CPD Mode $PASHS,CPD,FST,s Enables/disables fast CPD mode, where s is either ON or OFF. If this mode is set to ON, the rover receiver provides a fast CPD position solution. This command is relevant for ROVER receiver only. The default is ON. Example: Turn fast CPD OFF $PASHS,CPD,FST,OFF INF: CPD Information $PASHQ,CPD,INF,c This command queries the INF message where c is the optional output port. This message contains base and rover satellite status information.
Table 6.140: INF Message Structure (continued) Field Description Range d6 SVPRN for the Svs in the rover receiver 1-32 c7 Warning field description: + - no warnings C - warning in L1 measurements P - warning in L2 measurements - - warning in both measurements ‘+’ ‘-’ ‘C’ ‘P’ Units ...
Example: Set receiver to Base CPD mode $PASHS,CPD,MOD,BAS Table 6.141: CPD,MOD Parameter Table Parameter s Character String Description BAS ROV RBR RBB OFF CPD BASE mode CPD ROVER mode RVP (reverse vector processing) ROVER mode: outputs DBEN message only RVP BASE mode: it computes the RVP ROVER’s position Disable CPD mode $PASHQ,CPD,MOD,c Queries for the current CPD setting, where c is the optional output port. This message contains information about current CPD mode.
Table 6.142: CPD,MOD Message Structure (continued) Parameter Description Range d11 BPS transmission period or broadcast interval 0,10,30,100,300 s12 Which solution to output ‘CPD’, ‘RAW’, ‘RBP’ f13 Ambiguity fixing confidence level 99.0, 95.0, 99.0, 99.9 MTP: Multipath $PASHS,CPD,MTP,d1 This command sets the multipath parameter, where d1 is a code that describes the multi-path environment. This command is relevant for ROVER mode or RVP BASE mode only. Default is medium (2).
Table 6.144 on page 210 describes the binary structure of the OBEN message. Table 6.
Table 6.144: OBEN Message Structure (Binary Format) Type Baseline information Time Tag Units int Number of epochs available int Number of epochs used in solution int Number of satellites used for solution int Reference SV PRN number int PRNs of used satellites long L1 ambiguity int Number of epochs for each satellite float Standard deviation of L1 ambiguity cycles long L2 ambiguity 0.
Table 6.144: OBEN Message Structure (Binary Format) Type Description Units checksum Total Bytes 446 OUT: Solution Output $PASHS,CPD,OUT,d1 This command selects which position solution to output to the serial port and/or the data card. This command is relevant for ROVER mode or RVP BASE mode. The default is 1. Table 6.145: CPD,OUT Parameter Table Parameter Description d1 solution output selection: 0 - raw pseudo range solution (autonomous) 1 - CPD solution if available.
coordinates (if relevant) and antenna offset from reference point. This command is relevant for BASE mode or RVP ROVER mode. Table 6.146: CPD,PEB Parameter Table Parameter Description Units Default d1 Base coordinates broadcast interval. Only the following values are valid: 0, 10, 30, 60, 120, 300 (0 for no transmission).
Example: Set CPD update interval to 3 seconds. $PASHS,CPD,PER,3 POS: Set Base Position $PASHS,CPD,POS,m1,c2,m3,c4,f5 This command sets the base point position from the rover receiver. Table 6.149: CPD,POS Parameter Table Parameter Description Range m1 Latitude of base position in degrees and decimal minutes (ddmm.mmmmmmm). 0-8959.9999999 c2 Direction of latitude N = North, S = South ‘S’, ‘N’ m3 Longitude of base position in degrees and decimal minutes (dddmm.mmmmmmm) 0-17959.
PRT: Port Output Setting $PASHS,CPD,PRT,c This command sets the port to output DBEN and BPS messages, where c is the desired port. This is only relevant to BASE or RVP ROVER mode. Default port is B. Example: Output DBEN and BPS messages to port C. $PASHS,CPD,PRT,C RST: Reset CPD $PASHS,CPD,RST Reset the PNAV processing (Kalman filter reset). This command is relevant for ROVER mode or RVP BASE mode only.
UBP: Use Base Position $PASHS,CPD,UBP,d1 This command selects the base position to use in ROVER mode, where d1 indicates the desired base position. This command is relevant for ROVER mode only. Default is 1. Table 6.151: CPD,UBP Parameter Table Parameter d1 Description Base position to use: 0 = Use entered base position 1 = Use transmitted base position Range Default 0,1 1 Example: Use entered base station position.
User Coordinate Transformation (UCT) Commands The User Coordinate Transformation library includes user-defined transformation data (e.g., datums, grid systems, map projection parameters, etc.) and transformation functions. The user is able to: • • define and store one set of transformation parameters perform the transformation based on these parameters The UCT commands include: • • • Transformation Parameters Transformation Selection Coordinate Output Table 6.
DTM: Datum Selection $PASHS,DTM,s Select the geodetic datum used for position computation and measurements, where s is a 3 character string that defines a pre-defined datum or UDD (User Defined Datum). Parameters for user defined datum are entered with the $PASHS,UDD command (page 220). W84 is the default. For the list of available predefined datums, Appendix A, Reference Datums and Ellipsoids. Example: Select user defined datum for position computation.
FZN: Set UTM Zone to Fix $PASHS,FZN,d This command will set the UTM zone that will be held fixed, where d is the UTM zone and ranges from 1—60. this command is mostly used when the user is near a UTM boundary and outputing position in UTM coordinates and does not want the UTM coordinates to suddenly shift from one zone to another if the boundary is crossed. This command must be used with $PASHS,FUM. Example: Select UTM zone 10 to be fixed.
HGT: Height Model Selection $PASHS,HGT,s Select the height used in the position output messages, where s is a 3 character string: ELG: (default) output ellipsoidal heights in position messages. GEO: output orthometric heights in position messages using worldwide geoidal model. This does not affect the position output in the B-file or in the PBN message which are ECEF and always with respect to WGS84. To remain NMEA standard, the GGA message will always output geoidal height whatever the selection is.
Table 6.153: UDD Message Structure (continued) Param eter Description Range Units Default f3 Inverse Flattening in meters. 290.0000000301.0000000 meters 298.257223563 f4 Translation in x direction* ±1000.000 meters 0.00 f5 Translation in y direction* ±1000.000 meters 0.00 f6 Translation in z direction* ±1000.000 meters 0.00 f7 Rotation about x axis* + rotation is counter clockwise, and rotation is clockwise rotation, about the origin. ±10.000 sec 0.
The parameters description for each map projection type is as follows: Table 6.154: UDG Structure for Equatorial Mercator Field Description Range Units s1 Map projection type EMER n/a d2 Number of parameters for the selected projection 3 n/a f3 Longitude for the Central Meridian ±1800000.0000 dddmmss.ssss f4 False Northing ±10,000,000 meters f5 False Easting ±10,000,000 meters Table 6.
Table 6.157: UDG Structure for Stereographic (Polar and Oblique) Field Description Range Units s1 Map projection type STER n/a d2 Number of parameters for the selected projection 5 n/a f3 Latitude of the grid origin of the projection ±900000.0000 ddmmss.ssss f4 Longitude of the grid origin of the projection ±1800000.0000 ddmmss.ssss f5 Scale factor at center of projection 0.5-1.5 n/a f6 False Easting ±10,000,000 meters f7 False Northing ±10,000,000 meters Table 6.
Values are derived from tables which can be obtained from various sources, including NGS Publication 62-4 (1986 Reprint) which also includes discussion and definitions of applied formulas and parameters. Table 6.159: UDG Structure for Lambert Conic Conformal for SPC27 Description Range Name Map projection type.
f9 : ω = Φ - [1052.893882 - (4.483344 - 0.002352 * cos^2Φ) * cos^2 Φ] * sin Φ * cos Φ f11/f12/f13 : Ro = a * (1 - e^2) / (1 - e^2 *sin^2 Φo)^3/2 : radius of curvature in meridian plane at Φo No = a / (1-e^2 * sin^2 Φo)^1/2 : radius of curvature in prime vertical at Φo Table 6.
-1190000.0,352000.0,2000000,500000 Example: Set datum to grid transformation parameters. $PASHS,UDG,LC83,637 8240,297.323,121.4,18.9,0,0,0,1.5 $PASHQ,UDG,c Associated query command where c is the optional output port and is not required to direct the response message to the current communication port.
A Reference Reference Datums and Ellipsoids The following tables list geodetic datums and reference ellipsoid parameters. The translation values are in the format - From local to WGSG4. Table A.
Table A.1: Available Geodetic Datums (continued) Datum ID EUS A-2 Reference Ellipsoid Offset in meters (dX,dY,dZ Datum Description International 1924 -86, -98, -119 European 1979 (Austria, Finland, Netherlands, Norway, Spain, Sweden, Switzerland) FAH Clarke 1880 -346, Oman GAA International 1924 -133, -321, 50 Gandajika Base (Rep.
Reference Table A.
Table A.2: Reference Ellipsoids (continued) Ellipsoid A-4 a (metres) 1/f f Clarke 1866 6378206.4 294.9786982 0.00339007530409 Clarke 1880 6378249.145 293.465 0.00340756137870 Everest (india 1830) 6377276.345 300.8017 0.00332444929666 Everest (W.Malaysia&Singapore) 6377304.063 300.8017 0.00332444929666 Geodetic Reference System 1980 6378137.0 298.257222101 0.00335281068118 Helmert 1906 6378200.0 298.30 0.00335232986926 International 1924 6378388.0 297.00 0.
B Global Product Support If you have any problems or require further assistance, the Customer Support team can be reached through the following: telephone email Ashtech BBS system Internet Support • • • • Please refer to the documentation before contacting Customer Support. Many common problems are identified within the documentation and suggestions are offered for solving them.
If none of these suggestions solves the problem, contact the Customer Support team. To assist the Customer Support team, please ensure the following information is available: Table B.1: GPS/GIS Product Information Information Category Your actual numbers Receiver model Receiver serial # Software version # Software key serial # Firmware version # Options* A clear, concise description of the problem.
Corporate Web Page You can obtain data sheets, GPS information, application notes, and a variety of useful information from Ashtech’s Internet web page. In addition, you can access the BBS through the web site, and locate additional support areas such as frequently asked questions and training previews. The Internet address is: http://www.ashtech.
Supported Protocols B.2 lists the protocols supported by the Customer Support BBS. Table B.2: Protocols Protocol XMODEM Description Widely supported, uses 128-byte blocks. Good for moderately noisy lines. May cause file integrity problems by rounding. XMODEM-1k Uses 1024-byte blocks. Supposedly better for 2400 baud+. May cause file integrity problems by rounding. YMODEM Also known as YMODEM Batch, passes filename and size, eliminating rounding problems. Capable of multiple file transfer (batch).
Repair Centers In addition to repair centers in California and England, authorized distributors in 27 countries can assist you with your service needs. Ashtech Inc., Sunnyvale, California Voice: (408) 524-1680 or (800) 229-2400 Support fax: (408) 524-1500 Ashtech Europe Ltd.
B-6 Z-Family Technical Reference Manual
Index Symbols Index Index $GPALM, 149 $GPGGA, 155 $GPGLL, 157 $GPGRS, 158 $GPGSA, 160 $GPGSN, 161 $GPGSV, 163 $GPGXP, 165 $GPMSG, 166 $GPRMC, 175 $GPRRE, 176 $GPVTG, 183 $GPXDR, 184 $GPZDA, 186 $PASHQ,ALH, 76 $PASHQ,ALH,c, 76 $PASHQ,ALM, 148 $PASHQ,ANT, 79 $PASHQ,BEEP, 80 $PASHQ,CBN, 125 $PASHQ,CPD, 198 $PASHQ,CPD,ANT, 201 $PASHQ,CPD,DLK, 202 $PASHQ,CPD,INF, 206 $PASHQ,CPD,MOD, 208 $PASHQ,CPD,POS, 214 $PASHQ,CPD,STS, 215 $PASHQ,CTS, 80 $PASHQ,DAL, 151 $PASHQ,DBN, 130 $PASHQ,DTM, 218 $PASHQ,EPB, 132 $PASH
$PASHR,ALH, 76 $PASHR,ALM, 143 $PASHR,ANT, 79 $PASHR,BEEP, 80 $PASHR,CBN, 125 $PASHR,CLM, 80 $PASHR,CPD,ANT, 201 $PASHR,CPD,DLK, 202 $PASHR,CPD,INF, 206 $PASHR,CPD,MOD, 208 $PASHR,CPD,POS, 214 $PASHR,CPD,STS, 215 $PASHR,CTS, 81 $PASHR,DAL, 151 $PASHR,DTM, 218 $PASHR,EPB, 133 $PASHR,FLS, 84 $PASHR,INF, 87 $PASHR,ION, 89 $PASHR,LPS, 91 $PASHR,MDM, 93, 94 $PASHR,MPC, 134 $PASHR,OBN, 209 $PASHR,PBN, 139 $PASHR,PHE, 100 $PASHR,POS, 171 $PASHR,PPS, 105 $PASHR,PRT, 105 $PASHR,RID, 107 $PASHR,RPC, 130 $PASHR,RTR, 1
Index $PASHS,RTC,STH, 194 $PASHS,RTC,STI, 194 $PASHS,RTC,TYP, 195 $PASHS,SAV, 109, 112 $PASHS,SES, 109 $PASHS,SES,PAR, 109 $PASHS,SES,SET, 110 $PASHS,SIT, 112 $PASHS,SPD, 113 $PASHS,SVS, 114 $PASHS,TST, 117 $PASHS,UDD, 220 $PASHS,UNH, 117 $PASHS,USE, 117 $PASHS,VDP, 117 $PASHS,WAK, 118 Index $PASHS,NME,GRS, 158 $PASHS,NME,GSA, 159 $PASHS,NME,GSN, 161 $PASHS,NME,GSV, 163 $PASHS,NME,GXP, 164 $PASHS,NME,MSG, 166 $PASHS,NME,PER, 171 $PASHS,NME,POS, 99, 100 $PASHS,NME,RMC, 174 $PASHS,NME,RRE, 176 $PASHS,NME,SA
M data file naming, 8 output, 15 recording, 6 structure, 6 transferring, 16 types, 7 Default Parameters, 17 Differential correction, 47 GPS, 27 differential dase station, setup, 27 differential remote station, setup, 38 Disable differential mode, 192 DOP, 159 E Ellipsoidal height, 77 Enable Type of Message, 195 event marker, 12, 179 event marker message, 173 F fast RTK, 44 Fast RTK mode, 33 G GRS, 158 GSN, 161 GSV, 163 GXP, 164 H handshaking, 80, 81 I initialization, 5 integer ambiguity resolution, 44
S Index satellite in-view, 163 residual and position error, 176 status, 178 session programming, 10 setup combined differential and RTK base station, 29 differential base station, 27 differential remote station, 38 RTK base station, 28 RTK remote station, 39 shutter timing, 14 signal strength, 161 six-of-eight format, 49 SNR, 23 Surveys static, 119 synchronization, 16 synchronized RTK, 43 Synchronized RTK mode, 33 T time and date message, 184, 185 TTT, 173 U UTC time, 186 V velocity/course, 182 Z ZDA,
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