gpsrinex(1) GPSD Documentation gpsrinex(1)
NAME
gpsrinex - Read data from gpsd, convert to RINEX, and save to a file.
SYNOPSIS
gpsrinex [OPTIONS] [server[:port[:device]]]
gpsrinex -h
gpsrinex -V
DESCRIPTION
gpsrinex is a tool to connect to gpsd and output the received raw
measurements as a RINEX observation file. This is useful for sending
raw measurements (pseudorange and carrierphase) from gpsd to a Precise
Point Positioning (PPP) program or service.
gpsrinex does not require root privileges, but may be run as root.
Some of the examples in this file may not work when run under sudo. It
can be run concurrently with other tools connecting to a local or
remote gpsd without causing problems.
gpsrinex needs the GNSS receiver to be sending raw measurements to
gpsd. Only a few GNSS have this capability. In addition, the gpsd
driver for that GNSS must support raw mode. Currently only the u-blox
driver has this support. Only a few u-blox 8, 9, and 10, receivers
implement the required UBX-RXM-RAWX message. The NEO-M8T is known to
work, but requires configuration with ubxtool.
Before using ubxtool be sure to set the UBXOPTS environment variable
with the correct protocol version for your u-blox receiver. If your
protocol version is 32.00, you would do this:
export UBXOPTS="-P 32.00"
RINEX has its own definitions and abbreviations. Be sure to consult
their documentation. An observation file (.obs) contains data sets,
called epochs, that contain the pseudorange and carrierphase for each
satellite seen.
gpsrinex by default will acquire 20 epochs spaced apart by 30 seconds.
That will take 10 minutes to complete. Most users consider the 30
second interval to be optimal. Many PPP programs require at least 1 or
2 hours data, but no more than 24 or 48 hours of data. Most users
consider 4 to 6 hours of data as a minimum for good accuracy.
Additional hours will not yield much improvement.
The output will consist of one RINEX observation file that is ready to
be read by your PPP program. The default filename will be in the form:
gpsrinexYYYYjjjHHMMSS.obs. You can override this filename with the -f
option.
Optionally a server, TCP/IP port number and remote device can be given.
If omitted, gpsrinex connects to localhost on the default port (2947)
and watches all devices opened by gpsd.
OPTIONS
-?, -h, --help
Print a usage message and exit.
-D LVL, -debug LVL
Set debug level to LVL.
-f OUTFILE, --fileout OUTFILE
save RINEX into FILE.
-F INFILE, --filein INFILE
Read GPS JSON from file, not from a live gpsd.
-g CODES, --gnss CODES
Only output a GNSS system if the RINEX code is in CODES. C =
BeiDou, E = Galileo G = GPS, I = IRNSS, J = QZSS, R = GLONASS, S =
SBAS.
-i SECS, --interval SECS
wait [interval] seconds between epochs. The interval can be
specified to the millisecond. OPUS accepts intervals of 1, 2, 3, 5,
10, 15 or,30 seconds. OPUS then reduces the data to 30 second
intervals. Default is 30.000.
-n COUNT, --count COUNT
Causes COUNT epochs to be output. OPUS requires a minimum af 15
minutes, and a maximum of 48 hours, of data.
-V, --version
makes gpsrinex print its version and exit.
The following options set strings that are placed in the generated
RINEX 3 obs file. They do not change how gpsrinex computes anything.
--agency AGENCY
The name of the agency creating the current file.
--ant_num NUMBER
The antenna serial number.
--ant_type TYPE
The antenna type.
--comment CMT
Free form comment.
--marker_name NAME
The marker name.
--marker_type TYPE
The marker type
--observer OBSERVER
The name of the observer (you).
--rec_num NUM
The receiver serial number.
--rec_type TYPE
The receiver type.
--rec_vers VERS
The receiver version.
The following options set floating point numbers that are placed in the
generated RINEX obs file. They do not change how gpsrinex computes
anything.
--ant_e EASTING
The antenna easting from marker in meters.
--ant_h HEIGHT
The antenna height from marker in meters.
--ant_n NORTHING
The antenna northing from marker in meters.
ARGUMENTS
By default, clients collect data from the local gpsd daemon running on
localhost, using the default GPSD port 2947. The optional argument to
any client may override this behavior: [server[:port[:device]]]
For further explanation, and examples, see the ARGUMENTS section in the
gps(1) man page
EXAMPLES
Example 1:
Create a 4 hour .obs file. With a running gpsd accessible on the
localhost do all of the following, in order. Order matters.
The raw measurement messages are long. Be sure your serial port speed
is high enough:
gpsctl -s 115200
Disable all NMEA messages, and enable binary messages:
ubxtool -d NMEA
ubxtool -e BINARY
The NEO-M8N will only reliably output raw measurements when only the
GPS and QZSS constellations are enabled. If your PPP service can use
GLONASS, then enable that as well. Be sure to disable, before enable,
so as not to momentarily have too many constellations selected.
ubxtool, as recommended by u-blox, enables the QZSS constellation in
tandem with GPS. Disable all constellations, except GPS (and QZSS):
ubxtool -d BEIDOU
ubxtool -d GALILEO
ubxtool -d GLONASS
ubxtool -d SBAS
ubxtool -e GPS
Verify the constellations enabled:
ubxtool -p CFG-GNSS
Enable the good stuff, the raw measurement messages:
ubxtool -e RAWX
Verify raw data messages are being sent:
ubxtool | fgrep RAWX
You should see this output:
UBX-RXM-RAWX:
UBX-RXM-RAWX:
Collect 4 hours of samples at 30 second intervals, save the RINEX
observations in the file today.obs:
gpsrinex -i 30 -n 480 -f today.obs
Wait 4 hours. Enjoy a meal, or do some exercise. When gpsrinex
finishes, upload the file today.obs to your favorite PPP service.
Example 2:
Collect raw measurement data from a remote gpsd. Then process it later
with gpsrinex and gpsprof.
Ensure the receiver is configured properly, as shown in Example 1.
Grab 4 hours of raw live data from remote gpsd at 10.168.1.2:
gpspipe -x 14400 -R 10.168.1.2 > 4h-raw.ubx
When gpspipe is complete, the file 4h-raw.ubx will contain 4 hours of
raw UBX binary message. Convert that raw data in gpsd JSON with
gpsdecode:
gpsdecode < 4h-raw.ubx > 4h-raw.json
The file 4h-raw.json will now contain the data encoded as gpsd JSON.
Use gpsrinex to read that file and create a RINEX file:
gpsrinex -F 4h-raw.json
The RINEX file will be in the current directory with the file name
like: gpsrinexYYYYjjjHHMMSS.obs. See strftime(1) for how the date
formatting works
You can now use the JSON file to generate a polar plot of the used
satellites:
gpsprof -f polarused -T jpeg -r < 4h-raw.json > 4h-raw.plot
gnuplot < 4h-raw.plot > 4h-raw.png
Use the image viewer of your choice to view your skyview in 4h-raw.png
RETURN VALUES
0
on success.
1
on failure
SEE ALSO
One service known to work with gbsrinex output is at:
<https://webapp.geod.nrcan.gc.ca/geod/tools-outils/ppp.php>
OPUS requires 2 frequency observation files.
<https://www.ngs.noaa.gov/OPUS/>
The curious can find the RINEX 3.04 format described here:
<ftp://igs.org/pub/data/format/rinex304.pdf>
RINEX 4.02 is here:
<https://files.igs.org/pub/data/format/rinex_4.02.pdf>
gpsd(8), gps(1), gpsprof(1), gpsfake(1). ubxtool(1), gpsd_json(5),
strftime(1)
RESOURCES
Project web site: <https://gpsd.io/>
COPYING
This file is Copyright by the GPSD project
SPDX-License-Identifier: BSD-2-clause
AUTHOR
Gary E. Miller
GPSD, Version 3.27.1 2025-11-22 gpsrinex(1)
gpsd 3.27.1 - Generated Tue Dec 23 09:19:00 CST 2025