Postprocessing GPS & GLONASS with logs from ReachView v0.0.4

Reach Module / M+ / M2 RTK / PPK configuration
1

Can anyone share a simple command line workflow for RTKLIB? I tried with the new GPS & GLONASS setting, but RTKLIB seems to want to separate the GPS and GLONASS .pos files rather than combine them for me.

I see that ReachView can output a solution using both constellations, so there must be a way.

2

Hello!

You can’t post-process the solution log, as the data was already processed and this is basically the result.
Instead, you need use the raw data logs. We are currently working on automatic log conversion from raw receiver formats to RINEX and a post-processing tutorial.

However, here are some tips for now. Once you download the raw logs, you need to do two things:

  1. Convert ubx and rtcm3 logs to RINEX. This is achieved with RTKLIB’s convbin. A sample command would be something like ./convbin -r ubx /path/to/rov_XXXXXXXX.log or ./convbib -r rtcm3 /path/to/ref_XXXXXXXX.log for the base log. Take note off all the result files, like .obs, .nav and more.
  2. Post-process the logs with RTKLIB’s rnx2rtkp. Something like ./rnx2rtkp -c -o out.pos rinex_file1 rinex_file2 rinex_file3.... will generate forward/backward combined solution to the logs for better positioning results and put them in the out.pos file.

More info in RTKLIB docs.

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3

efedorov, thank you for those hints. For the others starting out, these were some things that were not apparent to me:

-RTKLIB thinks the raw ublox log files should have the suffix “.ubx” One can rename the .log files to .ubx or explicitly specify the format like so:
with convbin, use “-r ubx” in the command line
with rtkconv, open the dropdown menu and select the “ublox” format

-post-process both forward and backward solutions as efedorov suggested like so:
with rnx2rtkp, use “-c” in the command line
with rtkpost, in settings, open the dropdown menu and select “combined”

-in my application, I do not move the rover, or if I do move it, I stop the rover before and re-start it after, therefore I use the “static” setting instead of “kinematic” like so:
with rnx2rtkp, use “-p 3” in the command line
with rtkpost, in settings, open the dropdown menu and select “static”

What made my results instantly better was processing with combined forward and backward solutions. Before that, I had run many tests without getting a “fix,” only “float.” Now I am happy that I get a “fix” almost every time.

Back to GPS & GLONASS though:
Is there a way for RTKLIB to post-process GPS & GLONASS (& SBAS) together for a solution? If yes, please give an example. If no, is this something that happens in the ublox chip?

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