Changes between Version 1 and Version 2 of gps


Ignore:
Timestamp:
10/21/2017 10:56:42 PM (6 months ago)
Author:
Chris Lang
Comment:

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  • gps

    v1 v2  
    3333 * https://en.wikipedia.org/wiki/GLONASS
    3434
     35[=#beidou]
     36== BeiDou Navigation Satellite System (China) ==
     37The BeiDou Navigation Satellite System covers China and is planned to begin serving global customers upon its completion in 2020.
     38
     39[=#galileo]
     40== Galileo Navigation Satellite System (EU) ==
     41Galileo is the GNSS that is currently being created by the European Union (EU) and the European GNSS Agency (GSA). The system became operational in October 2011 and as of Dec 2016 the system has 18 of 30 satellites in orbit and is expected to reach full operational capability in 2019 with the complete 30-satellite system (24 operational and 6 active spares) expected by 2020.
     42
     43Reference:
     44 * https://en.wikipedia.org/wiki/Galileo_(satellite_navigation)
    3545
    3646[=#sbas]
     
    6070 * tighter integration
    6171
    62 Refer to the individual product manuals for details of connection such as:
     72Refer to the details below as well as the individual product manuals for details of connection such as:
    6373 * data serial port
    6474 * PPS GPIO
     
    8393== Hardware Devices Used ==
    8494
     95[=#zoem8q]
     96=== '''u-blox ZOE-M8G''' (GW63xx) ===
     97References:
     98- [http://dev.gateworks.com/datasheets/u-blox/ZOE-M8_DataSheet_(UBX-16008094).pdf ZOE-M8 Datasheet (UBX-16008094)]
     99- [http://dev.gateworks.com/datasheets/u-blox/u-blox8-M8_ReceiverDescrProtSpec_(UBX-13003221)_Public.pdf u-blox M8 Receiver Protocol Specification]
     100
     101Features:
     102 * 72-channel u-blox M8 concurrent position receiver engine supporting multiple concurrent Global Navigation Satellite System's (GNSS):
     103  - [#gps GPS]: L1C/A (1575.42MHz)
     104  - [#glonass GLONASS]: L1OF (1602MHz)
     105  - [#beidou BeiDou]: B1l
     106  - [#galileo Galileo]: E1B/C
     107  - [#qzss QZSS]: L1C/A (1575.42MHz)
     108  - [#sbas SBAS]: WAAS/EGNOS/MSAS: L1C/A (1575.42MHz)
     109 * [#dgps Differential GPS] (DGPS): [#rtcm RTCM] 10402.3:
     110 * Navigation Update Rate: 10Hz (GPS&GLONASS) or 18Hz (GPS) 
     111 * Accuracy:
     112  - Velocity: 0.05m/s
     113  - Heading: 0.3degrees
     114  - Horiz position: Autonomous 2.5m / SBAS 2.0m
     115  - PPS: 30ns RMS, 99% 60ns
     116 * Sensitivity:
     117  - Tracking & Navigation: -167dBm (GPS&GLONASS) -166dBm (GPS) -166dBm (GLONASS) -160dBm (BeiDou) -159dBm (Galileo)
     118  - Re-acquisition: -159dBm
     119  - Cold start: -147dBm
     120 * Acquisition:
     121  - Cold start Time-to-First-Fix (TTFF): 27s (GPS&GLONASS) or 30s (GPS only)
     122  - Hot start Time-to-First-Fix (TTFF): 1s
     123 * [#pps PPS]:
     124  - 30ns accuracy, configurable via UBX-CFG-TP5 with rate 0.25Hz to 10Mhz, high or low polarity, 0 to 2^32^ ms pulse width (see [http://dev.gateworks.com/datasheets/u-blox/u-blox8-M8_ReceiverDescrProtSpec_(UBX-13003221)_Public.pdf u-blox M8 Receiver Description including Protocol Specification] Chapter 18)
     125  - Default is 1Hz rising edge 100ms length
     126  - Note that for best PPS accuracy it is recommended to disable the SBAS subsystem
     127 * Communication:
     128  - 9600 baud, 8bit no parity, 1 stop bit, no flow control supporting multiple protocols:
     129   - [#nmea0183 NMEA]: Input / Output ASCII 0183 version 4.0 (configurable for 2.3 or 4.1)
     130   - [#ubx UBX]: Input / Output binary u-blox proprietary (see [wiki:gps#ubx ubx] below)
     131   - [#rtcm RTCM]: Input, messages 1,2,3,9
     132 * Active Antenna: 15dB to 50dB recommended
     133 * Power Consumption (not including active antenna power consumption):
     134  - ~40mA@1.8V 72mW (Continuous)
     135  - ~12.5mA@1.8V 22.5mW (PSM, 1Hz)
     136
     137Power-on Defaults:
     138 * 9600 baud, 8 data bits, no parity, 1 stop bit:
     139 * GPS & GLONASS enabled
     140 * SBAS enabled
     141 * output: NMEA: GGA, GLL, GSA, GSV, RMC, VTG, TXT messages
     142 * input: UBX, NMEA, RTCM
     143 * PPS: 100ms active high pulse at 1Hz
     144
     145Note that the GPS is not connected to an RTC, battery backup, or external flash on Gateworks designs (which disallows for permanent configuration storage and firmware upgrade)
     146
     147The ZOE-M8 GPS has the following improvements over the EVA-M8:
     148 - Has built in SAW and LNA for passive antenna support whereas the EVA-M8 can't support passive antenna
     149 - Uses an internal TCXO (temperature compensated) oscillator to provide improved accuracy over the EVA-M8 which uses a crystal
     150 - Smaller footprint (4.5mm x 4.5mm x 1.0mm) device vs (7mm x 7mm x 1.1mm)
     151 - Supports Galileo and BeiDou. EVA-8M only supports GPS GLONASS
     152 - Improved sensitivity (-167dBm vs -164dBm)
     153 - Faster acquisition time (26s vs 33s)
     154
     155
    85156[=#evam8m]
    86157=== '''u-blox EVA-M8M-0''' (GW553x) ===
    87 References
     158References:
    88159- [http://dev.gateworks.com/datasheets/u-blox/EVA-M8M-FW3_Datasheet.pdf EVA-M8M Datasheet]
    89160- [http://dev.gateworks.com/datasheets/u-blox/u-blox8-M8_ReceiverDescrProtSpec_(UBX-13003221)_Public.pdf u-blox M8 Receiver Protocol Specification]
     
    110181  - Hot start Time-to-First-Fix (TTFF): 1s
    111182 * [#pps PPS]:
    112   - configurable rate: 0.25Hz to 10Mhz
    113   - configurable polarity
    114   - configurable pulse-width: 2^32^ micro-seconds or duty-cycle
     183  - 30ns accuracy, configurable via UBX-CFG-TP5 with rate 0.25Hz to 10Mhz, high or low polarity, 0 to 2^32^ ms pulse width (see [http://dev.gateworks.com/datasheets/u-blox/u-blox8-M8_ReceiverDescrProtSpec_(UBX-13003221)_Public.pdf u-blox M8 Receiver Description including Protocol Specification] Chapter 18)
    115184  - Note that for best PPS accuracy it is recommended to disable the SBAS subsystem
    116185 * Communication:
     
    135204Note that the EVA-M8M is not connected to an RTC, battery backup, or external flash on Gateworks designs (which disallows for permanent configuration storage and firmware upgrade)
    136205
    137 
    138206[=#ubx]
    139207==== u-blox Receiver Protocol (UBX) ====
    140 UBX is a u-blox proprietary binary communication protocol used in their GNSS engines.
    141 
    142 Reference:
    143  * [https://www.u-blox.com/sites/default/files/products/documents/u-blox8-M8_ReceiverDescrProtSpec_(UBX-13003221)_Public.pdf M8 Receiver protocol: UBX-13003221]
     208UBX (u-blox Receiver Protocol) is a u-blox proprietary binary communication protocol used in their GNSS engines described in detail in [https://www.u-blox.com/sites/default/files/products/documents/u-blox8-M8_ReceiverDescrProtSpec_(UBX-13003221)_Public.pdf M8 Receiver protocol: UBX-13003221]
    144209
    145210
     
    181246  * [#nmea0183 NMEA 0183] v3.01, configurable 1 to 255 seconds between messages, supports: GGA, GLL, GSA, GSV, RMC, VTG, ZDA messages
    182247  * [#osp OSP™] (SiRF BINARY™) proprietary protocol
    183  * [#pps PPS]: rising edge 1Hz 4.2us (requires 5+ satellites)
     248 * [#pps PPS]:
     249  * ±1us accuracy, rising edge 1Hz 200ms width active-high when there are 5+ satellites used in a fix (not configurable)
    184250 * Internal LNA Gain:
    185251  * High Gain Mode '''(default)''' intended for use with passive antennas
     
    358424  * TSIP (Trimble Standard Interface Protocol)
    359425  * TAIP (Trimble ASCII Interface Protocol)
    360  * [#pps PPS]: rising edge
     426 * [#pps PPS]:
     427  * ±25ns 1 sigma accuracy, configurable pulse width between 61ns and 998ms and configurable delay between 61ns and 998ms (see [http://dev.gateworks.com/datasheets/trimble/CONDOR_UG_2C_75263-00.pdf PMTK_API_SET_OUTPUT_CTL (PMTK324)])
     428  * need to increase the PPS pulse width from the default 4.2us for pps-gpio to detect:
     429{{{#!bash
     430echo -n -e "\$PMTK324,0,0,1,0,1639344*24\r\n" > /dev/ttyS2 # 100ms pulse width on fix
     431}}}
     432  * if you want to also assert PPS when GPS position is not yet fixed:
     433{{{#!bash
     434echo -n -e "\$PMTK324,0,0,1,1,1639344*25\r\n" > /dev/ttyS2 # 100ms pulse width no fix
     435}}}
    361436
    362437Power-on Default configuration:
    363438 * 9600 baud
    364439 * output NMEA {{{RMC}}}, {{{GGA}}}, {{{GSV}}}, and {{{GSA}}} messages 1 time for every position fix (1Hz)
    365 
     440 * PPS: 4.2us active-high with no GPS fix required ('''see above for details on increasing pulse-width if you want to use PPS''')
    366441
    367442==== NMEA Configuration ====
     
    417492  * TAIP (Trimble ASCII Interface Protocol)
    418493 * [#pps PPS]:
    419   * rising edge 1Hz 61ns
    420   * requires fix interval set to 1000ms or less - see datasheet for details
     494  * ±350ns accuracy, 1Hz, configurable edge, configurable width between 100us and 500ms, configurable delay, and configurable fix type
     495  * Configuration is done via TSIP packets (Trimble Standard Interface Protocol) or NMEA PTNLSPS message see ​Trimble_CopernicusII_reference_manual for details:
     496{{{#!bash
     497echo -n -e "\$PTNLSPS,1,1000000,1,0*73\r\n" > /dev/ttygps # 100ms pulse width no fix
     498echo -n -e "\$PTNLSPS,2,1000000,1,0*70\r\n" > /dev/ttygps # 100ms pulse width fix required
     499echo -n -e "\$PTNLQPS\r\n" > /dev/ttygps # query
     500echo -n -e "\$PTNLSRT,F\r\n" > /dev/ttygps # factory reset (erase customer config, almanac, ephemeris, and last pos)
     501}}}
    421502
    422503Power-on Default configuration:
    423504 * 4800 baud
    424505 * output NMEA {{{GGA}}}, {{{VTG}}} messages 1 time for every position fix (1Hz)
     506 * 1Hz, rising edge, 4.2uS duration
    425507
    426508[=#antenna]