[teqc] Unexpected behavior when using -tbin with multi-day Trimble 5700 or R7 data
N.Palmer at gns.cri.nz
Tue Dec 18 12:56:59 MST 2018
After I noticed the differences I ran teqc with the simplest set of parameters I could with the same set of dat files. I used the current 2018Dec12 version of teqc and also the immediately previous version. The commands I used were along the lines of;
> teqc -tbin 1d A7R5 +obs + *.dat
> teqc A7R5 70181010.dat > A7R51010.18o
(for each day)
In the past I have used two different methods for logging daily files in 5700 receivers and I think this is likely the difference you are seeing.
One method is to create a powerup file on the receiver which starts logging initially and then create a logging session which stops logging just before midnight UT then restarts a new session at midnight. This is likely the type of files you have used.
The second method that I am currently using only has a single powerup file on the receiver which starts the receiver logging and then logs continuously but splits the raw data into 24 hour files. So there is no loss of lock over the UT boundary.
I will send a link in a separate email to a sample of this second type of data if you are interested in trying this.
Neville Palmer I Geodetic Surveyor
GNS Science I Te Pū Ao
From: Lou Estey <lou at unavco.org>
Sent: Wednesday, 19 December 2018 07:15
To: Neville Palmer <n.palmer at gns.cri.nz>
Cc: teqc at unavco.org
Subject: Re: [teqc] Unexpected behavior when using -tbin with multi-day Trimble 5700 or R7 data
Digging around I found in my sample stash a multi-day Trimble .dat file from a receiver which did not have clock steering. Thus, the same millisecond receiver clock resets are present as in your .dat file.
Using the 2018Dec12 version of teqc, I created daily RINEX obs using the '-tbin' option and created a multi-day RINEX obs without '-tbin' using the normal `teqc -tr d *.dat > t.obs`.
I then compared the L1 and L2 values at the beginning and end of each daily RINEX file to those values at the same epochs in the multi-day RINEX file. All the L1 and L2 values exactly match. In other words, I don't see what you report. (This wasn't repeated for an earlier version of teqc because there's nothing I can think of in at least several years that would change this result.) In other words, there is no reset of the receiver clock drift from file to file when using '-tbin'. Thus one could splice together all of the files created with '-tbin' and end up with epoch and observables exactly the same as translating the .dat into a single RINEX file.
I'm wondering if, besides the '-tbin' option, exactly the same version of teqc and the same options were used (or not used) when you and your colleague created the RINEX that you were commenting on. Could you check on this?
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