I'm looking to find the source for our latest errors in XY-GNSS positions with multiple receivers. (elevations are OK!)
We work with the Flemish Flepos VRS system and recently we have some (3) spots spread all over the country where we can't no longer reproduce our results within 5 cm horizontal. Normally 90% is within 3cm, now that drifts to ?ñ 15 cm ... some in challenging positions (urban canyons - hence the multipath question) but our Trimble R6-2 reports decent accuracies and low RMS.
At first we thougt at a malfunction in the receiver but we get the same results while testing with 2 other units with other controllers (I don't believe the controllers/software (Trimble Access 2014) are the problem but I don't want to exlcude anything for the moment.
FlePOS is updating receivers/antennas to GAL+Beidou and there has been a problem with 1 location with wrong XY positions ... but I guess that was a fix error during 1 week in a small region where we didn't operate during that period so that can't be the source of the drifting results. But we will contact FlePOS.
One more thing is we have for some weeks now very unstable weather with local heavy thunder & lightning - but working with a VRS system that should not be the problem either.
How do we find the source of these errors?
thanks for your help,
Christof.
Here are a couple of things that come to mind.?ÿ
1. Check for firmware updates for your receivers
2. Try observing during clear skies. I have a hard time believing thunderstorms in the area would not have an effect on positioning, even VRS.
3. Try Post processing your data. This may lead you to the error source.?ÿ
We work with the Flemish Flepos VRS system and recently we have some (3) spots spread all over the country where we can't no longer reproduce our results within 5 cm horizontal.
Interference from the Walloon Walpos VRS system?
Could be one or more bad base coordinates. Or a CORS antenna that has moved. Although one would hope either of those problems would be readily detected.?ÿ