NAME

gpscsv - dump the JSON output from gpsd as CSV

SYNOPSIS

gpscsv [OPTIONS] [host[:port[:device]]]

gpscsv -h

gpscsv -V

DESCRIPTION

gpscsv is a simple Python program for reading gpsd JSON data streams and outputting them in Comma Separated Values (CSV) format. It takes input from a specified gpsd and reports to standard output. The program runs until the gpsd dies, "-n COUNT" messages are processed, "-x SECONDS" have passed, or it is interrupted by ^C or other means.

gpscsv can only collect data that your gpsd is already sending. Use gpspipe to see what JSON message classes it is sending.

One good use of gpscsv is to create CSV files for use with the gnuplot program.

gpscsv does not need root, but will run fine as root.

OPTIONS

The program accepts the following options:

-?, -h, --help

Show help information and exit.

-c MCLASS, --class MCLASS

Select the JSON class messages of type MCLASS. Overrides the default class of TPV. See the Classes section below for more information.

--cvt-isotime

Convert fields named "time" from ISO time to UNIX time.

-D LVL, --debug LVL

Set debug level to LVL. Default 0. Higher arguments than 0 produce more debug output.

--device DEVICE

The DEVICE on the gpsd to connect to. Defaults to all.

-f FIELDS, -fields FIELDS

The FIELDS from the JSON message to dump to the output. Set FIELD to empty ('') for all initially seen fields. Default varies by CLASS.

--file FILE

Read JSON from FILE instead of from gpsd.

--header HEADER

Set header style to HEADER. 0 for no header, 1 output fields as header, 2 send fields as a comment ('#'). Defaults to 1.

--host HOST

Connect to the gpsd on HOST. Defaults to localhost.

-n COUNT, --count COUNT

Exit after outputting COUNT records. Set COUNT to 0 to disable. Default is 0

--port PORT

Use PORT to connect to gpsd. Defaults to 2947.

--separator SEPARATOR

Use SEPARATOR as the field separator. Default separator is a comma (',').

-V, --version

Show gpscsv version, and exit.

-x SECONDS, --seconds SECONDS

Exit after SECONDS number of seconds have passed. Set SECONDS to 0 to disable. Default is 0

All the above individual options may be specified multiple times, but t only the last one off each will be used.

Classes

Some of the gpsd JSON message classes include sub-classes. gpscsv allows direct access to them using a meta-class (MCLASS).

MCLASS Class Description

ALMANAC

SUBFRAME

ALMANAC from SUBFRAME JSON

HEALTH

SUBFRAME

HEALTH from SUBFRAME JSON

HEALTH2

SUBFRAME

HEALTH2 from SUBFRAME JSON

IONO

SUBFRAME

IONO from SUBFRAME JSON

NMCT

SUBFRAME

NMCT from SUBFRAME JSON

SUBFRAME1

SUBFRAME

SUBFRAME1 (Ephemeris 1) from SUBFRAME JSON

SUBFRAME2

SUBFRAME

SUBFRAME2 (Ephemeris 2) from SUBFRAME JSON

SUBFRAME3

SUBFRAME

SUBFRAME3 (Ephemeris 3) from SUBFRAME JSON

SAT

SKY

Individual satellites from SKY

SKY

SKY

The basic parts of SKY JSON

TPV

TPV

The basic parts of TPV JSON

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

Some basic standalone examples:

Grab three cycles of TPV data:

$ gpscsv -c TPV -n 3
time,lat,lon,altHAE
2021-07-28T22:38:37.000Z,44.0688638,-121.3140643,1108.223
2021-07-26T22:38:37.000Z,44.068863833,-121.314064333,1108.3
2021-07-28T22:38:38.000Z,44.0688637,-121.314065,1108.363

Grab one set of satellite data:

$ gpscsv -c SAT -n 1
time,gnssid,svid,PRN,az,el,ss,used,health
2021-07-28T22:37:46.000Z,0,8,8,311.0,28.0,33.0,True,1
2021-07-28T22:37:46.000Z,0,10,10,290.0,74.0,50.0,True,1
2021-07-28T22:37:46.000Z,0,15,15,45.0,18.0,31.0,False,1
2021-07-28T22:37:46.000Z,0,16,16,244.0,7.0,23.0,True,1
2021-07-28T22:37:46.000Z,0,18,18,109.0,43.0,37.0,True,1
2021-07-28T22:37:46.000Z,0,23,23,49.0,62.0,38.0,True,1
2021-07-28T22:37:46.000Z,0,24,24,87.0,16.0,28.0,True,1
2021-07-28T22:37:46.000Z,0,27,27,280.0,52.0,42.0,True,1
2021-07-28T22:37:46.000Z,0,32,32,188.0,32.0,42.0,True,1
2021-07-28T22:37:46.000Z,5,3,195,305.0,6.0,13.0,False,1
2021-07-28T22:37:46.000Z,6,2,66,38.0,8.0,21.0,False,1
2021-07-28T22:37:46.000Z,6,3,67,34.0,60.0,32.0,True,1
2021-07-28T22:37:46.000Z,6,4,68,226.0,63.0,34.0,True,1
2021-07-28T22:37:46.000Z,6,5,69,220.0,12.0,32.0,True,1
2021-07-28T22:37:46.000Z,6,11,75,-999,4.0,0.0,False,2
2021-07-28T22:37:46.000Z,6,12,76,47.0,0.0,0.0,False,1
2021-07-28T22:37:46.000Z,6,17,81,142.0,8.0,31.0,True,1
2021-07-28T22:37:46.000Z,6,18,82,138.0,57.0,40.0,True,1
2021-07-28T22:37:46.000Z,6,19,83,333.0,70.0,29.0,True,1
2021-07-28T22:37:46.000Z,6,20,84,323.0,10.0,0.0,False,1

Plot Examples

Some plot examples, do them in exact order shown:

Grab 100 samples of time,lat,lon,altHAE:

  $ gpscsv -n 100 --cvt-isotime  > tpv.dat

Grab 100 samples of time,epx,epy,epv,eph,sep

  $ gpscsv -n 100 --cvt-isotime -f time,epx,epy,epv,eph,sep > ep.dat

Grab 100 samples of time,xdop,ydop,vdop,tdop,hdop,gdop,pdop

  $ gpscsv -n 100 --cvt-isotime -c SKY  > sky.dat

Grab 100 samples of time,nSat,uSat

  $ gpscsv -n 100 --cvt-isotime -c SKY -f time,nSat,uSat  > sat.dat

Viewing CSV data with gnuplot

Start gnuplot in interactive mode:

  $ gnuplot

Some gnuplot housekeeping:

  # this are csv files
  gnuplot> set datafile separator ','
  # use the first line as title
  gnuplot> set key autotitle columnhead
  # X axis is UNIT time in seconds.
  gnuplot> set xdata time
  gnuplot> set timefmt "%s"

Now to plot time vs latitude, using tpv.dat from above:

  gnuplot> plot 'tpv.dat' using 1:2

Then to plot longitude and altHAE, in separate plots:

  gnuplot> plot 'tpv.dat' using 1:3
  gnuplot> plot 'tpv.dat' using 1:4

Put both latitude and longitude on one plot:

  gnuplot> set y2tics
  gnuplot> plot 'tpv.dat' using 1:2, '' using 1:3 axes x1y2

Plot epx, epy, epv, eph, and sep in one plot, using ep.dat from above:

  gnuplot> plot 'ep.dat' using 1:2, '' using 1:3, \
           '' using 1:4, '' using 1:5, '' using 1:6

Plot all the DOPs on one plot, from sky.dat above:

  gnuplot> plot 'sky.dat' using 1:2, '' using 1:3, '' using 1:4, \
           '' using 1:5, '' using 1:6, '' using 1:7, '' using 1:8

Plot nSat and uSat together:

  gnuplot> plot 'sat.dat' using 1:2, '' using 1:3

Lat/lon scatter plot:

  # x is no longer time
  gnuplot> set xdata
  gnuplot> plot 'tpv.dat' using 3:2 title 'fix'

RETURN VALUES

0

on success.

1

on failure

SEE ALSO

gpspipe(1), gpsd_json(5), gpsd(8), gnuplot(1)

RESOURCES

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

COPYING

This file is Copyright 2020 by the GPSD project
SPDX-License-Identifier: BSD-2-clause