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

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

       gpsd(8), gps(1), gpsprof(1), gpsfake(1). ubxtool(1), gpsd_json(5)

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