Discussion:
Pseudorange and carrier phase data in L1 only RINEX files
(too old to reply)
Mark Sims
2018-07-04 04:14:23 UTC
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I tried to do a test of sending three RINEX files to CSRS-PPP:
1) carrier phase + pseudorange
2) pseudorange only
3) carrier phase only

Oddly, file 3 was rejected as not having any usable observation data. Files 1 and 2 produced identical output. It looks like CSRS-PPP does not process carrier phase measurements for L1 only receivers! I had previously determined that they do not use doppler or signal strength measurements.

BTW, this was a 24 hour file from an M8T tracking GPS and GLONASS with 5 second intervals. The lat/lon/alt error ellipses were: 182/166/441 mm. So the Acutime GG is not as bad as I originally thought...
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Magnus Danielson
2018-07-04 04:37:23 UTC
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Hi,
Post by Mark Sims
1) carrier phase + pseudorange
2) pseudorange only
3) carrier phase only
Do you mean code phase pseudorange and carrier phase pseudorange?

Pseudorange is just range-measure with some noise and biases in it.
If you use only code phase to build pseudorange, then you end up with
code phase pseudorange. If you then extend it properly with carrier
phase data, you get carrier phase pseudorange. You can also cheat a
little and do a carrier phase smoothed code phase pseudorange.
Post by Mark Sims
Oddly, file 3 was rejected as not having any usable observation data. Files 1 and 2 produced identical output. It looks like CSRS-PPP does not process carrier phase measurements for L1 only receivers! I had previously determined that they do not use doppler or signal strength measurements.
Ah. Bummer. Could another service be of assistance?
Post by Mark Sims
BTW, this was a 24 hour file from an M8T tracking GPS and GLONASS with 5 second intervals. The lat/lon/alt error ellipses were: 182/166/441 mm. So the Acutime GG is not as bad as I originally thought...
Interesting.

Why do you reduce report-rate?

Cheers,
Magnus

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Anders Wallin
2018-07-04 06:22:14 UTC
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FWIW I have done some comparisons between the nrcan gpspp-code (behind the
csrs service), ESA gLab, and rtklib. There are mostly undocumented scripts
over here:
https://github.com/aewallin/ppp-tools
My tests were with dual-frequency RINEXes - haven't tried single-frequency
at all.

better and automated services for PPP time-transfer is on the to-do list,
but the list is long ;)

Anders
Post by Mark Sims
1) carrier phase + pseudorange
2) pseudorange only
3) carrier phase only
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