Position from OGRP and RTCM data

How to calculate a position taking observations from Goose and navigation data from Reference Receiver

Overview:

RTKLIB

• check out RTKLIB according to chapter 'Build RTKLIB with OGRP support on SBC',
  • make sure the executables 'convbin' and 'rnx2rtkp' are available then

Generate ogrp data (here observations) where RTCM data (here navigation data) exist already

• Run ogre_console on the goose and save the output
  taskset -c 1 ogre_console --gps-l1 --cold-start > goose_test.ogrp
  use the command options/parameters as necessary, e.g. more signals,
  see ogre_console --help

• Stop application(s) after test time has passed

  • Goose: stop application by '^c'

• If compatible RTCM3 data do not exist, they can be generated by a reference receiver, e.g. Septentrio

• 'compatible' means in terms of 'for the relevant time span'

Convert output to Rinex V3.03:

• Move the result files to some dir 'evaluation', from where you can easily access the rtklib apps
  • assume the filename of the RTCM data is data.rtcm
• Convert ogrp by rtklib tool convbin:
  ~/rtklib/build/convbin -r ogrp -v 3.03 goose_test.ogrp
  watch that files goose_test.obs, goose_test.nav exist
• Convert rtcm by rtklib tool convbin:
  ~/rtklib/build/convbin -r rtcm3 -v 3.03 data.rtcm
  watch that files data.obs, data.nav exist
• Notice that conversion of reference receiver output may be available in its SW already, other filenames might be generated

Calculate position

Now from the goose_test.obs and data.nav a position can be calculated:

• inform about possible options: rnx2rtkp --help
• ~/rtklib/build/rnx2rtkp data.nav goose_test.obs -p 0 -sys G -t
• if no success, check the timestamps in both files, they must overlap
• or add traces by option, see
  rnx2rtkp --help
-x level debug trace level (0:off) [0]