Baseline Too High

Our configuration has been working in fix. However, a lot of the time the baseline will start out really high and will take several minutes to come down to the correct baseline, at which point the solution will be at fix. Is there anything we can change to make this happen faster? Is this normal? Is it also possible that heat could be affecting the performance of the GPS (it is around 100 degrees Fahrenheit where I am)?

Could it be a problem that the base and the rover were too close together? They were about 3 meters away from each other and at different heights, although each has a circular groundplane.

Thank you.

Also, we’ve been having problems getting anything other than average single for the base coordinates. How do we get average float or average fix? And what does it mean to do this for the rover?

We’ve been using a coordinate accumulation time of 2 minutes. Is this reasonable, or would you suggest to do it longer?

Hi Jennifer,
For your baseline, it should still be accurate at 3M, I had a similar problem, I reduced the air transfer rate from 18 - 9 and it seemed to fix it but I am certain this was definitely the cause.
As for you base coordinates you won’t get average Float or Average Fix unless you have additional correction from a nearby CORS ( Continually Operating Reference System ) or VRS ( Virtual Reference System). When setting up the base I
use average single over 30 mins. This should be pretty accurate but not absolute but the Rover should still be highly accurate relative to the base station.
As for the temperature , Reach RS have an operating temp rangeof -20C (-4F) to +60C (140F) so this shouldnt be an issue
I am just a beginner myself so don’t take my word as final but this is my understanding of it so far. Hope yhishelp

1 Like

…but i am NOT certain this was definitely the cause.

@Jennifer set the positioning mode to kinematic and continuous in rtk settings, i hope this might help getting the baseline to its actual value faster. when it would look like it has stabilized, you can change the settings to static and fix and hold again.

Secondly, you surely need to do better than 2 mins for base station coordinates. Averaging in single mode isnt very accurate if you want absolute coordinates at rover end, you must need your base to connect with a CORS or place it on a point of known coordinates and input those manually.

As stated above, base cant do better then average singel solution without any other correction applyed, but should average a position to about couple of meters. I use base in static or singel mode and if you watch status when it gets a fairly stable position, this should also be the same at the rover end (grey bars), when sending correction to rover.

Also keep an eye on the age of differential and make sure you have read this about messages and speed (a bit down on the page)
https://docs.emlid.com/reachrs/common/reachview/base-mode/

This topic was automatically closed after 100 days. New replies are no longer allowed.