Ellipsoidal height variation for the same point

Hello Emlid community,
on 31_3_23 we took reading for the 3 different points by keeping Rover at their respective point. For each point reading ,time duration was around five minutes.
After an hour interval we did repeat the same process by taking the readings of three points & keeping base at the same place. It was seen that there is change in ellipsoidal height & distance between Base & Rover is around 6.5 to 7.5 km.
Below is the image attached for the results i got. It would be helpful to me if anyone from the emlid community would provide the reason behind this error we got in ellipsoidal height.

In my opinion, considering the chip’s vertical accuracy is 14mm+1ppm, 20-22mm is the absolute best you should expect. 26 to 49mm vertical over a 7km baseline is not bad at all, and depends on several factors that we most probably won’t be able to identify.


Thank you for your reply…

Hi Yash,

Welcome to our forum!

I agree with Gabriel’s assumption about instrumental accuracy considering your baseline. In fact, the resulting precision depends on many factors such as satellites’ geometry, environmental conditions, a baseline, and so on.

For instance, if you collect the same points at different time intervals during the day, the accuracy may change slightly. This occurs because the satellite constellation used for the calculation changes.

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