Seemingly inaccurate measurements RS+ with NTRIP

Hi, I am testing my NTRIP service and I have placed my Emlid RS+ in a static location. The signal is ok, good enough to see at least 12 satellites with corrections. It takes quite a while to get a ‘fix’, sometimes 20 minutes or more. Once I do I average for about 5 minutes. I then switch everything off (not touching the Emlid because I don’t want to disturb it) and then reset everything with the exact same settings, wait for ‘fix’, then average for another 5 minutes. Here are the results of the base coordinates from two separate measurements:

Lat: 37.8336833872
Long: -122.216224507
height: 139.096m

37.8336861049
-122.216226474
138.595m

…I am under the impression that these measurements are significantly off when I convert their differences into inches: Lat. 11.9”, Long. 6.8”, height 19.7” Any ideas why my repeat measurements are off this much? Perhaps I can average more? I believe my conversions are correct, but I am new to this so perhaps I’m making a mistake. Thank you for any input.

P.S. my base reference station is about 3km away. It is GPS/GLONASS multi-frequency.

You are averaging without fix for 5 minutes, you will get a difference without averaging with a correction source.

If you have a connection to NTRIP and are fixed while averaging for 5 minutes the difference will be minimal.

Can you post your raw-files?

I think one of these two files is incorrect because there is no common time between them.

Hi @jherbranson,

Thanks for the detailed info and sorry for the delay!

The long time of Fix obtaining in such a case might have resulted from two reasons:

Also, please make sure that RS+ is updated to the last stable firmware. It contains a lot of important improvements that enhanced overall stability with solution obtaining.

The difference in results seems rather unusual. To understand all of the aspects, please share the following information with us:

  • raw data log
  • base correction log
  • position log

The raw data log will help us to check the observational data quality. The base correction log will allow us to see whether the corrections from the base are received without any interruptions. To check the RTK solution during the whole survey, it’d be useful for us to analyze the position log.

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