Ubuntu Manpage: gpsrinex - Read data from gpsd convert to RINEX3 and save to a file.

Provided by: gpsd-clients_3.25-5ubuntu1_amd64

NAME

       gpsrinex - Read data from gpsd convert to RINEX3 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 3 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 and 9 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 3 observation file that is ready to be read by your PPP program. The
default filename will be in the form: gpsrinexYYYYDDDDHHMM.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.

-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.

--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 3 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 3 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, feed the data to gpsfake:

gpsfake -1 -P 3000 4h-raw.ubx

In another window, feed the data to gpsrinex. Use -n 10000000 so that all the data from the raw file is
used:

gpsrinex -i 30 -n 1000000 :3000

Repeat the process with gpsfake to send the data to gpsprof.

RETURN VALUES

       0
           on success.

       1
           on failure

RESOURCES

       Project web site: https://gpsd.io/

COPYING

       This file is Copyright 2013 by the GPSD project
       SPDX-License-Identifier: BSD-2-clause

AUTHOR

       Gary E. Miller

GPSD, Version 3.25                                 2023-01-10                                        GPSRINEX(1)