Legacy GPS
I have found myself with a Sokkia Radian IS … a nifty little unit.
Problem is, the date is compromised(2020(?( rollover). I can record data, and I have used Sokkia Planning to make a Rinex. But I do not remember how to change the Rinex file to work with OPUS. The previous rollover seemed to be simple … maybe it involved an ephemeris file(?). I also hoped to find firmware on the Topcon site, but I don’t think there is a firmware upgrade.
I also see that OPUS requires 30 second epochs, and I se no way to decimate my readings to 30 seconds, or even 60 seconds.
I wonder if anyone still uses the Sokkia Radian RS
Any help would be appreciated
Thanks, John
- 6 Replies
I wrote software to clean up RINEX files, fix the rollover date, I can’t remember if it decimates, it might.
If you are careful, you can use a plaintext editor (I use notepad++) to fix the dates. The format of the RINEX files is very specific so you need to be careful. I had to take some time to learn about the RINEX file format.
OPUS will decimate the data, unless the file exceeds the OPUS maximum size limit. Uploading large undecimated files to OPUS does slow down your upload and consume excess resources on the (free!) OPUS servers, so I try to be a good citizen and decimate before I upload. There are a number of free tools out there to decimate, some only work on older RINEX formats.
OPUS will take care of the decimation issue itself. It simply only uses the 30 second epochs no matter what you submit. There is no need for you to worry about that.
There is if the file is too large — OPUS will reject it. This can happen with 1-second RINEX files.
Little bit more info on RepairRinex, it removes observations that would cause the RINEX file to be rejected, eg, it removes satellites with incomplete observations and updates the number of satellite’s, it does this based on AUSPOS’ priority list, I’ve found it works well for OPUS also.
Also if the duration is longer than 24 hours, it removes partial days, which are rejected by Auspos.
12. AUSPOS uses a priority list for the observations included in the RINEX file. This priority list translates to the below:
For RINEX version 2:
L1 frequency carrier phase: L1
L2 frequency carrier phase: L2
L1 frequency pseudo-range: P1 C1
L2 frequency pseudo-range: P2 C2
- For each RINEX file, please ensure that there is at least one observation type for each of the two frequencies and for both carrier-phase and pseudo-range measurements.
- For a RINEX v2 file, if BOTH C1 and P1 (C2 and P2) code measurements exist, P1 (P2) is given priority to be processed. In this case, please ensure all GPS satellites contain P1 (P2) measurements.
- For a RINEX v2 file, if only C1 (C2) code measurements exist, please ensure all GPS satellites contain C1 (C2) measurements.
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This reply was modified 4 days, 13 hours ago by pfirmst. Reason: formatting
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