PPK for base station

Hi all,

I have started to run out of ides to sort this problem, so thought I would let the community have a crack.

Dual reach modules undertaking survey on both land and sea. Base station in exact same location for both survey (back to back days) over unknown point - the roof of a building with clear skyview.
Trying to determine position of base station using NZ equivalent of a CORS data set, which I think have a freq of 30s.
I use the .17o files form the station with a wildcard identify in the base field of RTKPOST ("*.17o")

Once a solid fix on base is made I can PPK the rover data.

Base raw data is quite long, so had to crop based on time to prevent memory allocation error.

I ran RTKPOST ver.2.4.3 Emlid b27 with recommended settings, and then a range of different Elevation Mask Values, Forward and Combined solution types etc. etc.

Ultimately, I ended up with a very big range in base elevation (several m!!) from the different settings/results.
I’m also getting float values in there, which considering the base is not moving at all in anyway, I have a really good, close reference station, and the time series is a good length, I would have thought I could get all fixes and accuracy of at least <10 mm in the vertical.

Anyway, would be stoked if someone could have a crack; or at least provide some input.
Have tried to upload a zip file but no good, so available from here:


Persistence pays off a little.
I settled on a configuration, combined solution was really working a lot better.
Below is a plot of the sample points for elev, lat and long for 3 different elevation masks. You can see that 40 degrees started to cut data off, as did 25. My basic interpretation is that 35 degrees is the best bask as the data is the most consistent looking… any how, moving on to PPK of rover now with new location for base = the mean values for lat/lon/elev of the 35 degree mask PPK of the base station

Here is from my pre run with 15degree mask. A bit high AOD
Z=24.646 RMS 0.0091.

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