pygnssutils

Current Status | Installation | gnssstreamer CLI | gnssserver CLI | gnssntripclient CLI | gnssmqttclient CLI | ubxsimulator | ubxsetrate CLI | ubxcompare CLI | RTK Demonstration | Troubleshooting | Graphical Client | Author & License

pygnssutils is an original series of Python GNSS utility classes and CLI tools built around the following core libraries from the same stable:

• pyubx2 - UBX parsing and generation library
• pynmeagps - NMEA parsing and generation library
• pyrtcm - RTCM3 parsing library
• pyspartn - SPARTN parsing library

Originally developed in support of the PyGPSClient GUI GNSS application, the utilities provided by pygnssutils can also be used in their own right:

1. GNSSStreamer class and its associated gnssstreamer (formerly gnssdump) CLI utility. This is essentially a configurable bidirectional input/output wrapper around the pyubx2.UBXReader class with flexible message formatting, filtering and output handling options for NMEA, UBX and RTCM3 protocols.
2. GNSSSocketServer class and its associated gnssserver CLI utility. This implements a TCP Socket Server for GNSS data streams which is also capable of being run as a simple NTRIP Server/Caster.
3. GNSSNTRIPClient class and its associated gnssntripclient CLI utility. This implements a simple NTRIP Client which receives RTCM3 or SPARTN correction data from an NTRIP Server and (optionally) sends this to a designated output stream.
4. GNSSMQTTClient class and its associated gnssmqttclient CLI utility. This implements a simple SPARTN IP (MQTT) Client which receives SPARTN correction data from an SPARTN IP location service and (optionally) sends this to a designated output stream.
5. ubxsimulator utility. This provides a basic simulation of a GNSS receiver serial stream by generating synthetic UBX or NMEA messages based on parameters defined in a json configuration file.
6. ubxsave CLI utility. This saves a complete set of configuration data from any Generation 9+ u-blox device (e.g. NEO-M9N or ZED-F9P) to a file. The file can then be reloaded to any compatible device using the ubxload utility.
7. ubxload CLI utility. This reads a file containing binary configuration data and loads it into any compatible Generation 9+ u-blox device (e.g. NEO-M9N or ZED-F9P).
8. ubxsetrate CLI utility. A simple utility which sets NMEA or UBX message rates on u-blox GNSS receivers.
9. ubxcompare CLI utility. Utility for comparing two or more u-blox config files in either text (*.txt) or binary (*.ubx) format. Output files from the ubxsave utility can be used as input files.

The pygnssutils homepage is located at https://github.com/semuconsulting/pygnssutils.

Current Status

Sphinx API Documentation in HTML format is available at https://www.semuconsulting.com/pygnssutils.

Contributions welcome - please refer to CONTRIBUTING.MD.

Bug reports and Feature requests - please use the templates provided. For general queries and advice, post a message to one of the pygnssutils Discussions channels.

---

Installation

pygnssutils is compatible with Python 3.9-3.13.

In the following, python3 & pip refer to the Python 3 executables. You may need to substitute python for python3, depending on your particular environment (on Windows it's generally python). It is strongly recommended that the Python 3 binaries (\Scripts or /bin) and site_packages directories are included in your PATH (most standard Python 3 installation packages will do this automatically if you select the 'Add to PATH' option during installation).

The recommended way to install the latest version of pygnssutils is with pip:

python3 -m pip install --upgrade pygnssutils

If required, pygnssutils can also be installed into a virtual environment, e.g.:

python3 -m pip install --user --upgrade virtualenv
python3 -m virtualenv env
source env/bin/activate (or env\Scripts\activate on Windows)
python3 -m pip install --upgrade pygnssutils
...
deactivate

For Conda users, pygnssutils is also available from conda forge:

conda install -c conda-forge pygnssutils

---

GNSSStreamer and gnssstreamer CLI (formerly gnssdump)

class pygnssutils.gnssstreamer.GNSSStreamer(**kwargs)

gnssstreamer (formerly gnssdump) is a command line utility for concurrent bidirectional communication with a GNSS datastream - typically a GNSS receiver. It supports NMEA, UBX, RTCM3, SPARTN, NTRIP and MQTT protocols.

• The CLI utility can acquire data from any one of the following sources:

  • port: serial port e.g. COM3 or /dev/ttyACM1 (can specify --baudrate and --timeout)
  • filename: fully qualified path to binary input file e.g. /logs/logfile.bin
  • socket: socket e.g. 192.168.0.72:50007 (port must be specified)
  • stream: any other instance of a stream class which implements a read(n) -> bytes method

• It offers a variety of data filtering options based on message protocol, identity and periodicity via the --protfilter and --msgfilter arguments e.g. --protfilter 2 --msgfilter NAV-PVT(10) will filter output to the UBX protocol and NAV-PVT message type and will limit NAV-PVT periodicity to 1 every 10 seconds.

• It can format the filtered data via the --format argument:

  • 1 = parsed as object (e.g. NMEAMessage, UBXMessage) (default)
  • 2 = raw binary
  • 4 = hexadecimal string
  • 8 = tabulated hexadecimal
  • 16 = parsed as string
  • 32 = JSON

  or any OR'd combination thereof - e.g. --format 9 outputs the parsed version of a UBX message alongside its tabular hexadecimal representation.

• It can output the formatted and filtered data to a variety of output channels via the --clioutput and --output arguments:

  • 0 = stdout (terminal) (default)
  • 1 = file
  • 2 = serial
  • 3 = TCP socket server
  • 4 = Python lambda expression (which could, for example, be used to format the output into a user-defined f-string).

• It can also support a variety of concurrent input data sources via the --cliinput and --input arguments:

  • 0 = none (default)
  • 1 = RTK NTRIP RTCM caster
  • 2 = RTK NTRIP SPARTN caster
  • 3 = RTK MQTT SPARTN source (see gnssmqttclient for MQTT client configuration details)
  • 4 = serial port
  • 5 = binary file.

  Data from these sources will be uploaded to the GNSS datastream provided this datastream supports write() operations. A principal use case for this input facility is to monitor a GNSS receiver's output while processing incoming RTK correction data via pygnssutil's in-built NTRIP or MQTT (SPARTN IP) clients or a RXM-PMP (SPARTN L-Band) serial stream. Alternatively, binary file input could, for example, contain a series of UBX CFG-* configuration commands to be applied to a u-blox receiver.

For help and full list of optional arguments, type:

gnssstreamer -h

Command line arguments can be stored in a configuration file and invoked using the -C or --config argument. The location of the configuration file can be set in environment variable GNSSSTREAMER_CONF.

gnssstreamer can be run as a systemd service on Linux servers - see Install gnssstreamer as service.

GNSSStreamer - the underlying Python class of gnssstreamer - is essentially a configurable input/output wrapper around the pyubx2.UBXReader class which can be used within Python scripts. It supports custom input and output handlers via user-defined callback functions.

Refer to the Sphinx API documentation for further details.

CLI Examples:

Assuming the Python 3 scripts (bin) directory is in your PATH, the CLI utility may be invoked from the shell thus:

1. Serial input from receiver with output passed to Python lambda expression:

gnssstreamer --port /dev/ttyACM1 --baudrate 9600 --timeout 5 --quitonerror 1 --protfilter 2 --msgfilter NAV-PVT --clioutput 4 --output "lambda msg: print(f'lat: {msg.lat}, lon: {msg.lon}')"

lat: 37.23345, lon: -115.81512
lat: 37.23347, lon: -115.81515
lat: 37.23343, lon: -115.81513

2. File input with output to terminal in parsed and tabulated hexadecimal formats:

(--clioutput 0 is the default, so this argument could be omitted):

gnssstreamer --filename pygpsdata.log --quitonerror 2 --format 9 --clioutput 0 --verbosity 2

2024-08-15 09:31:48.68 - INFO - pygnssutils.gnssstreamer - Parsing GNSS data stream from file: <_io.BufferedReader name='pygpsdata.log'>...

<UBX(NAV-STATUS, iTOW=09:47:37, gpsFix=3, gpsFixOk=1, diffSoln=0, wknSet=1, towSet=1, diffCorr=0, carrSolnValid=1, mapMatching=0, psmState=0, spoofDetState=1, carrSoln=0, ttff=33377, msss=1912382)>
000: b562 0103 1000 f80c da1b 03dd 0208 6182  | b'\xb5b\x01\x03\x10\x00\xf8\x0c\xda\x1b\x03\xdd\x02\x08a\x82' |
016: 0000 3e2e 1d00 633d                      | b'\x00\x00>.\x1d\x00c=' |

<UBX(NAV-DOP, iTOW=09:47:37, gDOP=1.55, pDOP=1.32, tDOP=0.8, vDOP=1.11, hDOP=0.72, nDOP=0.59, eDOP=0.42)>
000: b562 0104 1200 f80c da1b 9b00 8400 5000  | b'\xb5b\x01\x04\x12\x00\xf8\x0c\xda\x1b\x9b\x00\x84\x00P\x00' |
016: 6f00 4800 3b00 2a00 9b75                 | b'o\x00H\x00;\x00*\x00\x9bu' |

<UBX(NAV-TIMEGPS, iTOW=09:47:37, fTOW=422082, week=2216, leapS=18, towValid=1, weekValid=1, leapSValid=1, tAcc=10)>
000: b562 0120 1000 f80c da1b c270 0600 a808  | b'\xb5b\x01 \x10\x00\xf8\x0c\xda\x1b\xc2p\x06\x00\xa8\x08' |
016: 1207 0a00 0000 3566                      | b'\x12\x07\n\x00\x00\x005f' |

3. Socket input with output to terminal in JSON format:

gnssstreamer --socket 192.168.0.20:50010 --format 32 --msgfilter 1087 --verbosity 2

2024-08-15 09:31:48.68 - INFO - pygnssutils.gnssstreamer - Parsing GNSS data stream from: <socket.socket fd=3, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=0, laddr=('127.0.0.1', 57399), raddr=('127.0.0.1', 50010)>...

{"class": "<class 'pyrtcm.rtcmmessage.RTCMMessage'>", "identity": "1087", "payload": {"DF002": 1087, "DF003": 0, "GNSSEpoch": 738154640, "DF393": 1, "DF409": 0, "DF001_7": 0, "DF411": 0, "DF412": 0, "DF417": 0, "DF418": 0, "DF394": 1152921504606846976, "NSat": 1, "DF395": 1073741824, "NSig": 1, "DF396": 1, "DF405_01": 0.00050994, "DF406_01": 0.00194752, "DF407_01": 102, "DF420_01": 0, "DF408_01": 0, "DF404_01": 0.5118}},...]

4. Serial input with output to socket server using remote instances of gnssstreamer as socket clients:

gnssstreamer as socket server:

gnssstreamer --port /dev/tty.usbmodem101 --clioutput 3 --output 192.168.0.27:50011 --format 2 --verbosity 2

2024-08-15 09:00:04.769 - INFO - pygnssutils.gnssstreamer - Parsing GNSS data stream from: Serial<id=0x1016467a0, open=True>(port='/dev/tty.usbmodem101', baudrate=38400, bytesize=8, parity='N', stopbits=1, timeout=3, xonxoff=False, rtscts=False, dsrdtr=False)...
2024-08-15 09:00:09.952 - INFO - pygnssutils.socket_server - client ('192.168.0.58', 57964) has connected
2024-08-15 09:00:23.839 - INFO - pygnssutils.socket_server - client ('192.168.0.36', 57968) has connected
2024-08-15 09:00:34.29 - INFO - pygnssutils.socket_server - client ('192.168.0.36', 57968) has disconnected
2024-08-15 09:00:36.37 - INFO - pygnssutils.socket_server - client ('192.168.0.58', 57964) has disconnected
^C2024-08-15 09:00:35.196 - INFO - pygnssutils.gnssstreamer - Messages input:    {'NAV-DOP': 8, 'NAV-PVT': 31, 'NAV-SAT': 8}
2024-08-15 09:00:35.197 - INFO - pygnssutils.gnssstreamer - Messages filtered: {}
2024-08-15 09:00:35.197 - INFO - pygnssutils.gnssstreamer - Messages output:   {'NAV-DOP': 8, 'NAV-PVT': 31, 'NAV-SAT': 8}
2024-08-15 09:00:35.197 - INFO - pygnssutils.gnssstreamer - Streaming terminated, 47 messages processed with 0 errors.

gnssstreamer as socket client:

gnssstreamer -S 192.168.0.27:50011

<UBX(NAV-PVT, iTOW=07:56:45, year=2024, month=8, day=15, hour=7, min=56, second=45, validDate=1, validTime=1, fullyResolved=1, validMag=0, tAcc=27, nano=376074, fixType=3, gnssFixOk=1, diffSoln=0, psmState=0, headVehValid=0, carrSoln=0, confirmedAvai=1, confirmedDate=1, confirmedTime=1, numSV=30, lon=-115.81512, lat=37.23345, height=5278, hMSL=5264, hAcc=2840, vAcc=2527, velN=-5, velE=-7, velD=8, gSpeed=8, headMot=0.0, sAcc=223, headAcc=180.0, pDOP=0.91, invalidLlh=0, lastCorrectionAge=0, reserved0=1044570318, headVeh=0.0, magDec=0.0, magAcc=0.0)>
...

5. Serial input with concurrent NTRIP RTK input, outputting to Python lambda expression:

(in this example, gnssstreamer will pass NMEA GGA data back to the NTRIP caster every 10 seconds)

gnssstreamer --port /dev/tty.usbmodem101 --msgfilter "NAV-PVT" --cliinput 1 --input "http://rtk2go.com:2101/MYMOUNTPOINT" --rtkuser myusername --rtkpassword mypassword --rtkggaint 10 --clioutput 4 --output "lambda msg: print(f'lat: {msg.lat}, lon: {msg.lon}, hAcc: {msg.hAcc/1000} m, dgps {['NO RTK','RTK FLOAT','RTK FIXED'][msg.carrSoln]}, corr age {msg.lastCorrectionAge}')"

lat: 37.2306465, lon: -115.8102969, hAcc: 2.505 m, dgps NO RTK, corr age 0
lat: 37.2306464, lon: -115.8102969, hAcc: 2.502 m, dgps NO RTK, corr age 0
...
lat: 37.2306447, lon: -115.8102895, hAcc: 2.929 m, dgps NO RTK, corr age 3
lat: 37.2306462, lon: -115.8102946, hAcc: 1.373 m, dgps RTK FLOAT, corr age 3
lat: 37.2306465, lon: -115.8102957, hAcc: 1.022 m, dgps RTK FLOAT, corr age 3
...
lat: 37.2306502, lon: -115.8102974, hAcc: 0.68 m, dgps RTK FLOAT, corr age 3
lat: 37.2306763, lon: -115.8103495, hAcc: 0.016 m, dgps RTK FIXED, corr age 3
lat: 37.2306762, lon: -115.8103495, hAcc: 0.015 m, dgps RTK FIXED, corr age 3

6. Serial input with concurrent binary configuration file input:

(in this example the f9pconfig.ubx file contains a series of UBX CFG-MSG commands which disable NMEA messages and enable UBX messages)

gnssstreamer --port /dev/tty.usbmodem101 --cliinput 5 --input f9pconfig.ubx --verbosity 2

2024-09-05 07:39:33.886 - INFO - pygnssutils.gnssstreamer - Starting GNSS reader/writer using Serial<id=0x104cddb70, open=True>(port='/dev/tty.usbmodem101', baudrate=9600, bytesize=8, parity='N', stopbits=1, timeout=3, xonxoff=False, rtscts=False, dsrdtr=False)...
<NMEA(GNRMC, time=06:39:34, status=A, lat=37.2306246667, NS=N, lon=-115.8103376667, EW=W, spd=0.055, cog=, date=2024-09-05, mv=, mvEW=, posMode=A, navStatus=V)>
2024-09-05 07:39:34.32 - INFO - pygnssutils.gnssstreamer - Data input: b'\xb5b\x06\x01\x08\x00\xf0\n\x00\x00\x00\x00\x00\x00\ti'
...
2024-09-05 07:39:34.35 - INFO - pygnssutils.gnssstreamer - Data input: b'\xb5b\x06\x01\x08\x00\x01\x11\x00\x00\x00\x00\x00\x00!"'
<NMEA(GNGLL, lat=37.2306246667, NS=N, lon=-115.8103376667, EW=W, time=06:39:34, status=A, posMode=A)>
<UBX(ACK-ACK, clsID=CFG, msgID=CFG-MSG)>
<UBX(ACK-NAK, clsID=CFG, msgID=CFG-MSG)>
...
<UBX(ACK-ACK, clsID=CFG, msgID=CFG-MSG)>
<UBX(NAV-PVT, iTOW=06:39:35, year=2024, month=9, day=5, hour=6, min=39, second=35, validDate=1, validTime=1, fullyResolved=1, validMag=0, tAcc=32, nano=386888, fixType=3, gnssFixOk=1, diffSoln=0, psmState=0, headVehValid=0, carrSoln=0, confirmedAvai=1, confirmedDate=1, confirmedTime=1, numSV=10, lon=-115.8103373, lat=37.8106243, height=101139, hMSL=52655, hAcc=3317, vAcc=3070, velN=10, velE=20, velD=62, gSpeed=22, headMot=0.0, sAcc=300, headAcc=180.0, pDOP=1.89, invalidLlh=0, lastCorrectionAge=0, reserved0=1044570318, headVeh=0.0, magDec=0.0, magAcc=0.0)>
...
Messages input:    {'ACK-ACK': 46, 'ACK-NAK': 24, 'GAGSV': 1, 'GBGSV': 1, 'GLGSV': 3, 'GNGGA': 1, 'GNGLL': 1, 'GNGSA': 5, 'GNRMC': 1, 'GNVTG': 1, 'GPGSV': 3, 'GQGSV': 1, 'NAV-DOP': 1, 'NAV-PVT': 3, 'NAV-SAT': 1}
Messages filtered: {}
Messages output:   {'ACK-ACK': 46, 'ACK-NAK': 24, 'GAGSV': 1, 'GBGSV': 1, 'GLGSV': 3, 'GNGGA': 1, 'GNGLL': 1, 'GNGSA': 5, 'GNRMC': 1, 'GNVTG': 1, 'GPGSV': 3, 'GQGSV': 1, 'NAV-DOP': 1, 'NAV-PVT': 3, 'NAV-SAT': 1}
Streaming terminated, 93 messages processed with 0 errors.

Installing gnssstreamer as a systemd service on Linux

This example should work for most Linux distributions running systemd and python3>=3.8, including Raspberry Pi OS (substitute dnf for apt as necessary).

The example gnssstreamer.conf file will set up gnssstreamer as a multi-client TCP socket server accessible on hostip:50012 (check TCP port 50012 is allowed through any active firewall).

1. Install pygnssutils into a virtual environment as follows:

cd ~ # or a base directory of your choice
sudo apt install python3-virtualenv # if not already installed
python3 -m virtualenv pygnssutils
source pygnssutils/bin/activate
python3 -m pip install --upgrade pygnssutils
deactivate

2. Copy the example gnssstreamer.conf and gnssstreamer.service files to the host machine and edit them according to your preferred configuration. If installed as above, Environment=GNSSSTREAMER_CONF=/home/username/gnssstreamer.conf and ExecStart=/home/username/pygnssutils/bin/gnssstreamer.
3. Run the following shell commands and verify the status:

sudo cp gnssstreamer.service /etc/systemd/system
sudo systemctl daemon-reload
sudo systemctl enable gnssstreamer.service
sudo systemctl start gnssstreamer.service
systemctl status gnssstreamer.service # look for 'enabled' and 'active (running)'

GNSSSocketServer and gnssserver CLI

class pygnssutils.gnssserver.GNSSSocketServer(**kwargs)

GNSSSocketServer is essentially a wrapper around the GNSSStreamer and SocketServer classes (the latter based on the native Python ThreadingTCPServer framework) which uses queues to transport data between the two classes.

CLI Usage - Default Mode:

In its default configuration (ntripmode=0) gnssserver acts as an open, unauthenticated CLI TCP socket server, reading the binary data stream from a host-connected GNSS receiver and broadcasting the data to any local or remote TCP socket client capable of parsing binary GNSS data.

It supports most of gnssstreamer's formatting capabilities and could be configured to output a variety of non-binary formats (including, for example, JSON or hexadecimal), but the client software would need to be capable of parsing data in such formats.

Assuming the Python 3 scripts (bin) directory is in your PATH, the CLI utility may be invoked from the shell thus:

gnssserver --inport "/dev/tty.usbmodem101" --baudrate 115200 --hostip 192.168.0.27 --outport 50012 --verbosity 2

2024-08-15 09:12:25.443 - INFO - pygnssutils.gnssserver - Starting server (type CTRL-C to stop)...
2024-08-15 09:12:25.443 - INFO - pygnssutils.gnssserver - Starting input thread, reading from /dev/tty.usbmodem101...
2024-08-15 09:12:25.461 - INFO - pygnssutils.gnssstreamer - Parsing GNSS data stream from: Serial<id=0x103966e60, open=True>(port='/dev/tty.usbmodem101', baudrate=115200, bytesize=8, parity='N', stopbits=1, timeout=3, xonxoff=False, rtscts=False, dsrdtr=False)...
2024-08-15 09:12:25.949 - INFO - pygnssutils.gnssserver - Starting output thread, broadcasting on 192.168.0.27:50012...
2024-08-15 09:12:36.953 - INFO - pygnssutils.gnssserver - Client ('192.168.0.34', 58207) has connected. Total clients: 1
2024-08-15 09:12:43.35 - INFO - pygnssutils.gnssserver - Client ('192.168.0.34', 58207) has disconnected. Total clients: 0

gnssserver can be run as a daemon process (or even a service) but note that abrupt termination (i.e. without invoking the internal server.shutdown() method) may result in the designated TCP socket port being unavailable for a short period - this is operating system dependant.

Command line arguments can be stored in a configuration file and invoked using the -C or --config argument. The location of the configuration file can be set in environment variable GNSSSERVER_CONF.

For help and full list of optional arguments, type:

gnssserver -h

Refer to the Sphinx API documentation for further details.

CLI Usage - NTRIP Mode:

gnssserver can also be configured to act as a single-mountpoint NTRIP Server/Caster (ntripmode=1), broadcasting RTCM3 RTK correction data to any authenticated NTRIP client on the standard 2101 port using the mountpoint name pygnssutils (NB: to use with standard NTRIP clients, output format must be set to binary (2) - this is the default, so the argument can be omitted):

gnssserver --inport "/dev/tty.usbmodem14101" --hostip 192.168.0.27 --outport 2101 --ntripmode 1 --protfilter 4 --format 2 --ntripuser myuser --ntrippassword mypassword --verbosity 2

NOTE THAT this configuration is predicated on the host-connected receiver being an RTK-capable device (e.g. the u-blox ZED-F9P) operating in 'Base Station' mode (either 'SURVEY_IN' or 'FIXED') and outputting the requisite RTCM3 RTK correction messages (1005, 1077, 1087, 1097, 1127, 1230). NTRIP server login credentials are set via command line arguments or environment variables PYGPSCLIENT_USER and PYGPSCLIENT_PASSWORD.

Clients

gnssserver will work with any client capable of parsing binary GNSS data from a TCP socket. Suitable clients include, but are not limited to:

1. (in default mode) pygnssutils's gnssstreamer cli utility invoked thus:

gnssstreamer --socket hostip:outport

2. (in NTRIP mode) Any standard NTRIP client, including BKG's NTRIP client (BNC), ublox's legacy ucenter NTRIP client, or pygnssutil's gnssntripclient cli utility invoked thus:

gnssntripclient -S hostip -P 2101 -M pygnssutils --ntripuser myuser --ntrippassword mypassword --verbosity 2

3. The PyGPSClient GUI application.

---

GNSSNTRIPClient and gnssntripclient CLI

class pygnssutils.gnssntripclient.GNSSNTRIPClient(app=None, **kwargs)

The GNSSNTRIPClient class provides a basic NTRIP Client capability and forms the basis of a gnssntripclient CLI utility. It receives RTCM3 or SPARTN correction data from an NTRIP server and (optionally) sends this to a designated output stream. NTRIP server login credentials are set via command line arguments or environment variables PYGPSCLIENT_USER and PYGPSCLIENT_PASSWORD.

CLI Usage:

Assuming the Python 3 scripts (bin) directory is in your PATH, the CLI utility may be invoked from the shell thus:

To retrieve the sourcetable and determine the closest available mountpoint to the reference lat/lon, leave the mountpoint argument blank (the port defaults to 2101):

gnssntripclient --server rtk2go.com --port 2101 --https 0 --datatype RTCM --ntripversion 2.0 --ggainterval -1 --reflat 37.23 --reflon 115.81 --ntripuser myuser --ntrippassword mypassword --verbosity 2

2024-08-15 09:22:21.174 - INFO - pygnssutils.gnssntripclient - Closest mountpoint to reference location(37.23, 115.81) = MYBASE, 313.65 km.
2024-08-15 09:22:21.176 - INFO - pygnssutils.gnssntripclient - Complete sourcetable follows...
[['ACAKO', 'Kovin', 'RTCM 3.2', '1005(30),1074(1),1084(1),1094(1)', '2', 'GPS+GLO+GAL', 'SNIP', 'SRB', '44.75', '21.01', '1', '0', 'sNTRIP', 'none', 'B', 'N', '3200', ''], ['ACASU', 'Subotica', 'RTCM 3.2', '1005(30),1074(1),1084(1),1094(1)', '2', 'GPS+GLO+GAL', 'SNIP', 'SRB', '46.06', '19.52', '1', '0', 'sNTRIP', 'none', 'B', 'N', '3360', ''], ['ADS-SAH', 'Ciudad Real', 'RTCM 3.2', '1005(1),1074(1),1084(1),1094(1),1230(1)', '', 'GPS+GLO+GAL', 'SNIP', 'ESP', '39.05', '-4.06', '1', '0', 'sNTRIP', 'none', 'B', 'N', '0', ''], [['AGSSIAAP', 'Acheres', 'RTCM 3.0', '1004(1),1006(13),1012(1),1033(31)', '2', 'GPS+GLO', 'SNIP', 'FRA', '48.97', '2.17', '1', '0', 'sNTRIP', 'none', 'N', 'N', '2540', '']
...

To retrieve correction data from a designated mountpoint (this will send NMEA GGA position sentences to the server at intervals of 60 seconds, based on the supplied reference lat/lon):

gnssntripclient --server rtk2go.com --port 2101 --https 0 --mountpoint MYBASE --datatype RTCM --ggainterval 60 --reflat 37.23 --reflon 115.81 --ntripuser myuser --ntrippassword mypassword --verbosity 2

2024-08-15 09:24:34.872 - INFO - pygnssutils.gnssntripclient - Streaming RTCM data from rtk2go.com:2101/MYBASE ...
2024-08-15 09:24:35.897 - INFO - pygnssutils.gnssntripclient - RTCMMessage received: 1019
2024-08-15 09:24:35.898 - INFO - pygnssutils.gnssntripclient - RTCMMessage received: 1020
2024-08-15 09:24:35.898 - INFO - pygnssutils.gnssntripclient - RTCMMessage received: 1042
...

Command line arguments can be stored in a configuration file and invoked using the -C or --config argument. The location of the configuration file can be set in environment variable GNSSNTRIPCLIENT_CONF.

For help and full list of optional arguments, type:

gnssntripclient -h

Refer to the Sphinx API documentation for further details.

---

GNSSMQTTClient and gnssmqttclient CLI

class pygnssutils.gnssmqttclient.GNSSMQTTClient(app=None, **kwargs)

The GNSSMQTTClient class provides a basic SPARTN IP (MQTT) Client capability and forms the basis of a gnssmqttclient CLI utility. It receives RTK correction data from a SPARTN IP (MQTT) location service (e.g. the u-blox / Thingstream PointPerfect service) and (optionally) sends this to a designated output stream.

CLI Usage:

The clientid provided by the location service may be set as environment variable MQTTCLIENTID. If this environment variable is set and the TLS certificate (*.crt) and key (*.pem) files provided by the location service are placed in the user's HOME directory, the utility can use these as default settings and may be invoked without any arguments.

Assuming the Python 3 scripts (bin) directory is in your PATH, the CLI utility may be invoked from the shell thus (press CTRL-C to terminate):

gnssmqttclient --clientid yourclientid --server pp.services.u-blox.com --port 8883 --region eu --mode 0 --topic_ip 1 --topic_mga 1 --topic_key 1 --tlscrt '/Users/{your-user}/device-{your-clientid}-pp-cert.crt' --tlskey '/Users/{your-user}/device-{your-client-id}-pp-key.pem'} --spartndecode 0 --clioutput 0 --verbosity 2

2024-08-15 09:14:50.544 - INFO - pygnssutils.gnssmqttclient - Starting MQTT client with arguments {'server': 'pp.services.u-blox.com', 'port': 8883, 'clientid': 'your-client-id', 'region': 'eu', 'mode': 0, 'topic_ip': 1, 'topic_mga': 1, 'topic_key': 1, 'tlscrt': '/Users/myuser/device-your-client-id-pp-cert.crt', 'tlskey': '/Users/myuser/device-your-client-id-pp-key.pem', 'spartndecode': 0, 'output': None}.
2024-08-15 09:14:50.840 - INFO - pygnssutils.gnssmqttclient - RXM-SPARTN-KEY
2024-08-15 09:14:50.854 - INFO - pygnssutils.gnssmqttclient - MGA-INI-TIME-UTC
2024-08-15 09:14:50.858 - INFO - pygnssutils.gnssmqttclient - MGA-GPS-EPH
...

Command line arguments can be stored in a configuration file and invoked using the -C or --config argument. The location of the configuration file can be set in environment variable GNSSMQTTCLIENT_CONF.

For help and full list of optional arguments, type:

gnssmqttclient -h

Refer to the pyspartn documentation for further details on decrypting encrypted (eaf=1) SPARTN payloads.

---

ubxsimulator utility

EXPERIMENTAL

Provides a simple simulation of a GNSS serial stream by generating synthetic UBX or NMEA messages based on parameters defined in a json configuration file. Can simulate a motion vector based on a specified course over ground and speed. Location of configuration file can be set via environment variable UBXSIMULATOR.

Example usage:

ubxsimulator --simconfigfile "/home/myuser/ubxsimulator.json" --interval 1000 --timeout 3 --verbosity 3

from os import getenv
from pygnssutils import UBXSimulator, UBXSIMULATOR
from pyubx2 import UBXReader

with UBXSimulator(
    configfile=getenv(UBXSIMULATOR, "/home/myuser/ubxsimulator.json"),
    interval=1000,
    timeout=3,
) as stream:
    ubr = UBXReader(stream)
    for raw, parsed in ubr:
        print(parsed)

Generates mock acknowledgements (ACK-ACK) for valid incoming UBX commands and polls.

See sample ubxsimulator.json configuration file in the \examples folder, and the Sphinx API documentation.

NB: Principally intended for testing Python GNSS application functionality. There is currently no attempt to simulate real-world satellite geodetics, though this could be done using e.g. the Python skyfield library and the relevant satellite TLE (orbital elements) data. We may look into adding such functionality as and when time permits. Contributions welcome.

Command line arguments can be stored in a configuration file and invoked using the -C or --config argument. The location of the configuration file can be set in environment variable UBXSIMULATOR_CONF.

---

ubxsave CLI

GENERATION 9+ DEVICES ONLY (e.g. NEO-M9N or ZED-F9P)

class pygnssutils.ubxconfig.UBXSaver(file, stream, **kwargs)

CLI utility which saves Generation 9+ UBX device configuration data to a file. ubxsave polls configuration data via the device's serial port using a series of CFG-VALGET poll messages. It parses the responses to these polls, converts them to CFG-VALSET command messages and saves these to a binary file. This binary file can then be loaded into any compatible UBX device (e.g. via the ubxload utility) to restore the saved configuration.

The CFG-VALSET commands are stored as a single transaction. If one or more fails on reload, the entire set will be rejected.

NB: The utility relies on receiving a complete set of poll responses within a specified waittime. If the device is exceptionally busy or the transmit buffer is full, poll responses may be delayed or dropped altogether. If the utility reports errors, try increasing the waittime.

CLI Usage:

ubxsave --port /dev/ttyACM1 --baudrate 9600 --timeout 0.02 --outfile ubxconfig.ubx --verbosity 1

For help and full list of optional arguments, type:

ubxsave -h

---

ubxload CLI

GENERATION 9+ DEVICES ONLY (e.g. NEO-M9N or ZED-F9P)

class pygnssutils.ubxconfig.UBXLoader(file, stream, **kwargs)

CLI utility which loads UBX configuration (CFG-VALSET) data from a binary file (e.g. one created by the ubxsave utility) and loads it into the volatile memory (RAM) of a compatible Generation 9+ UBX device via its serial port. It then awaits acknowledgements to this data and reports any errors.

CLI Usage:

ubxload --port /dev/ttyACM1 --baudrate 9600 --timeout 0.05 --infile ubxconfig.ubx --verbosity 1

For help and full list of optional arguments, type:

ubxload -h

---

ubxsetrate CLI

class pygnssutils.ubxconfig.UBXSetRate(**kwargs)

A simple CLI utility to set NMEA or UBX message rates on u-blox receivers via a serial port.

CLI Usage:

Assuming the Python 3 scripts (bin) directory is in your PATH, the CLI utility may be invoked from the shell thus:

This example sets the UBX NAV-HPPOSLLH message rate to 1:

ubxsetrate --port /dev/ttyACM0 --baudrate 38400 --msgClass 0x01 --msgID 0x14 --rate 1

Opening serial port /dev/ttyACM0 @ 38400 baud...

Sending configuration message <UBX(CFG-MSG, msgClass=NAV, msgID=NAV-HPPOSLLH, rateDDC=1, rateUART1=1, rateUART2=1, rateUSB=1, rateSPI=1, reserved=0)>...

Configuration message sent.

Refer to pyubx2 documentation for available msgClass and msgID values. msgClass and msgID can be specified in either integer or hexadecimal formats.

Alternatively, the msgClass keyword can be set to one of the following group values (in which case the msgID keyword can be omitted):

• "allubx" - set rate for all available UBX NAV messages
• "minubx" - set rate for a minimum set of UBX NAV messages (NAV-PVT, NAV-SAT)
• "allnmea" - set rate for all available NMEA messages
• "minnmea" - set rate for a minimum set of NMEA messages (GGA, GSA, GSV, RMC, VTG)

For help and full list of optional arguments, type:

ubxsetrate -h

---

ubxcompare CLI

class pygnssutils.ubxcompare.UBXCompare(infiles, form, diffsonly)

A simple CLI utility for comparing the contents of two or more u-blox configuration files. Files can be in text (*.txt) format (as used by u-center or ArduSimple) or binary (*.ubx) format (as used by PyGPSClient or ubxsave).

e.g.

ubxcompare --infiles "simpleRTK2B_FW132_Rover_1Hz-00.txt, simpleRTK2B_FW132_Rover_10Hz-00.txt" --format 0 --diffsonly 1

24 configuration commands processed in simpleRTK2B_FW132_Rover_1Hz-00.txt

24 configuration commands processed in simpleRTK2B_FW132_Rover_10Hz-00.txt

2 files processed, list of differences in config keys and their values follows:

CFG_MSGOUT_NMEA_ID_GSA_UART1 (DIFFS!): {1: '1', 2: '0'}
CFG_MSGOUT_NMEA_ID_GSA_UART2 (DIFFS!): {1: '1', 2: '0'}
CFG_MSGOUT_NMEA_ID_GSV_UART1 (DIFFS!): {1: '1', 2: '0'}
CFG_MSGOUT_NMEA_ID_GSV_UART2 (DIFFS!): {1: '1', 2: '0'}
CFG_RATE_MEAS (DIFFS!): {1: '1000', 2: '100'}

Total config keys: 1475. Total differences: 5.

For help and full list of optional arguments, type:

ubxcompare -h

---

NTRIP RTK demonstration using gnssserver and gnssntripclient

Assuming your host is connected to an RTK-capable receiver (e.g. ZED-F9P) operating in Base Station mode (see configuring base station), you can run gnssserver as a local NTRIP caster and gnssntripclient as a remote NTRIP client. You may have to amend your firewall settings to make the caster available outside your local LAN. This configuration is only recommended for personal testing and diagnostic purposes and not for production use.

NTRIP Caster - gnssserver

gnssserver --inport /dev/ttyACM1 --baudrate 38400 --format 2 --protfilter 4 --hostip 192.168.0.27 --outport 2101 --ntripmode 1 --ntripversion 2.0 --ntripuser youruser --ntrippassword yourpassword --verbosity 2

2024-08-23 10:12:00.239 - INFO - pygnssutils.gnssserver - Starting server (type CTRL-C to stop)...
2024-08-23 10:12:00.239 - INFO - pygnssutils.gnssserver - Starting input thread, reading from /dev/ttyACM1...
2024-08-23 10:12:00.256 - INFO - pygnssutils.gnssstreamer - Parsing GNSS data stream from: Serial<id=0x1016039d0, open=True>(port='/dev/ttyACM1', baudrate=38400, bytesize=8, parity='N', stopbits=1, timeout=3, xonxoff=False, rtscts=False, dsrdtr=False)...
2024-08-23 10:12:00.744 - INFO - pygnssutils.gnssserver - Starting output thread, broadcasting on 192.168.0.27:2101...
2024-08-23 10:12:45.7 - INFO - pygnssutils.gnssserver - Client ('192.168.0.54', 60783) has connected. Total clients: 1
2024-08-23 10:12:48.10 - INFO - pygnssutils.gnssserver - Client ('192.168.0.54', 60783) has disconnected. Total clients: 0
...etc.
^C2024-08-23 10:14:12.834 - INFO - pygnssutils.gnssserver - Stopping server...
2024-08-23 10:14:12.835 - INFO - pygnssutils.gnssstreamer - Messages input:    {'1005': 132, '1077': 132, '1087': 132, '1097': 132, '1127': 132, '1230': 132, '4072': 132, 'NAV-DOP': 132, 'NAV-PVT': 132, 'NAV-SAT': 33, 'NAV-SVIN': 132}
2024-08-23 10:14:12.835 - INFO - pygnssutils.gnssstreamer - Messages filtered: {'NAV-DOP': 132, 'NAV-PVT': 132, 'NAV-SAT': 33, 'NAV-SVIN': 132}
2024-08-23 10:14:12.835 - INFO - pygnssutils.gnssstreamer - Messages output:   {'1005': 132, '1077': 132, '1087': 132, '1097': 132, '1127': 132, '1230': 132, '4072': 132}
2024-08-23 10:14:12.835 - INFO - pygnssutils.gnssstreamer - Streaming terminated, 924 messages processed with 0 errors.
2024-08-23 10:14:13.204 - INFO - pygnssutils.gnssserver - Server shutdown.

NTRIP Client - gnssntripclient

gnssntripclient --server 192.168.0.27 --port 2101 --https 0 --mountpoint pygnssutils --ntripversion 2.0 --ntripuser youruser --ntrippassword yourpassword --verbosity 2

2024-08-23 10:12:45.8 - INFO - pygnssutils.gnssntripclient - Streaming rtcm data from 192.168.0.27:2101/pygnssutils ...
2024-08-23 10:12:45.8 - INFO - pygnssutils.gnssntripclient - Message received: 1097
2024-08-23 10:12:45.9 - INFO - pygnssutils.gnssntripclient - Message received: 1127
2024-08-23 10:12:45.9 - INFO - pygnssutils.gnssntripclient - Message received: 1230
2024-08-23 10:12:45.47 - INFO - pygnssutils.gnssntripclient - Message received: 1005
2024-08-23 10:12:46.8 - INFO - pygnssutils.gnssntripclient - Message received: 4072
2024-08-23 10:12:46.12 - INFO - pygnssutils.gnssntripclient - Message received: 1077
2024-08-23 10:12:46.13 - INFO - pygnssutils.gnssntripclient - Message received: 1087
2024-08-23 10:12:46.13 - INFO - pygnssutils.gnssntripclient - Message received: 1097
2024-08-23 10:12:46.13 - INFO - pygnssutils.gnssntripclient - Message received: 1127
...etc.
^C2024-08-23 10:12:47.480 - INFO - pygnssutils.gnssntripclient - Disconnected

---

Troubleshooting

1. SPARTNTypeError or SPARTNParseError when parsing encrypted messages with 16-bit gnssTimetags (timeTagtype=0), e.g. GAD or some OCB messages:

   pyspartn.exceptions.SPARTNTypeError: Error processing attribute 'group' in message type SPARTN-1X-GAD
   

   This is almost certainly due to an invalid decryption key and/or basedate. Remember that keys are only valid for a 4 week period, and basedates are valid for no more than half a day. Note also that different GNSS constellations use different UTC datums e.g. GLONASS timestamps are based on UTC+3. Check with your SPARTN service provider for the latest decryption key(s), and check the original creation date of your SPARTN datasource.

2. SSL: CERTIFICATE_VERIFY_FAILED error when attempting to connect to SPARTN MQTT service using gnssmqttclient on MacOS:

   [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:1000)
   

   This is because gnssmqttclient is unable to locate the RootCA certificate for the MQTT Broker. This can normally be resolved as follows:

   • Install the latest version of certifi: python3 -m pip install --upgrade certifi
   • Run the following command from the terminal (substituting your Python path and version as required): /Applications/Python\ 3.12/Install\ Certificates.command

3. Unable to install cryptography library required by pyspartn on 32-bit Linux platforms:

   Building wheel for cryptography (PEP 517): started
   Building wheel for cryptography (PEP 517): finished with status 'error'
   

   Refer to cryptography installation README.md.

---

Graphical Client

A python/tkinter graphical GPS client which utilises the pygnssutils library and supports NMEA, UBX, RTCM3 and NTRIP protocols is available at:

https://github.com/semuconsulting/PyGPSClient

---

Author & License Information

[email protected]

pygnssutils is maintained entirely by unpaid volunteers. It receives no funding from advertising or corporate sponsorship. If you find the utility useful, please consider sponsoring the project with the price of a coffee...