RTK Fix good for 1-2 hours, but very unstable over longer durations

Hi @all,

I am just now getting the time to play with my Reach Kit. I have the base installed on the roof of my house, and the rover antenna set up in the garden (statically), not a 100% clear view of the horizon, but “realistic” conditions for a ground vehicle in my yard. That is, there is a bush and a smallish tree nearby.

I had the setup running for several hours, and at first (after some minutes acquiring a fix), it worked perfectly. The first minutes saw a very small drift in the range of few centimeters. It steadily, but very slowly, continued drifting towards the south east, which got much worse when it went from Fix to Float.

Screenshots of the experiment can be seen at https://imgur.com/a/bg5h9.

Does this sound or look like something to be expected, or is something wrong in my setup, and the position of a static rover should stay basically glued fix relative to the base station?

I am using ReachView v2.5.3-r0, with a small hack that gives me relative XYZ positions on the rover, as they are more readable to me.

If any other information is required, please let me know.

Thank you,

Hi @ploedoff,

Raw, position and correction logs are the only way to analyze what happened. Could you please upload them?

Thanks for getting back to me.

I see. I have been disabled logs on the base station, which was a mistake. Having read up on the matter a bit, it seems I should also first make sure my base position is correct. I am therefore going to get some local RINEX data and measure my house’s position.

I will then repeat my measurements and make sure I get all logs. This may take some days, as it’s a hobby project and subject to priority precedence :wink:

In the mean time, what are theoretically the right settings? Base in static mode makes sense, but what about the rover? It will be on a slow moving vehicle in the end, so I’m thinking Kinematic mode? I left message selection and frequency on default, but GPS AR mode is another mistery for me for now. The theoretical concepts are mostly clear, but I have no intuition or practical experience yet.


You were correct leaving all settings on default :slight_smile: It is the best choice when starting to get to know the equipment.

For rover Kinematic will definitely be the way to go. Make sure to lift the receiver above the ground level, there is a reason why surveyors wear them on poles. Make groundplanes for antennas as per our docs.

Start tests from good conditions and make them worse as you gain experience.