Phantom 4 RTK vertical system settings case

[Kereplaz]

Hello everyone. I am trying to use Metashape with a Phantom 4 RTK drone to get survey accurate results in my country (LTU) but cant seem to get the Z coordinate right.

The RTK service here (LitPos) provides z axis height in "height above wgs84 ellipsoid" (meters) format. And the end result of the project should be in LKS94  (epsg 3346) coordinate system with vertical height above GRS 1980 ellipsoid (from 0 meters).

I can achieve good results that do correspond to reality and test GCP's from surveyors with another software solution. So I think it is a matter of good settings which I cannot find. Can anyone help?

When using the RTK drone I have checked the "load camera location accuracy" in preferences. I do enter the project reference system as LKS94 in the reference settings menus, but in the end I get wrong heights in the 3D results. Point cloud is about 20 meters above absolute elevation.

Any help would be appreciated. If I can provide more information or clarification if needed

[Jobbo90]

Hi Kereplaz,

Did you add GCP's to the project and apply that during your alignment steps? And did you apply optimize camera steps along the way?

Try the following procedures and see if it helps:
http://www.rslab.se/agisoft-photoscan-pro/

Regards!

[Kereplaz]

Hey, the point of using the RTK drone is not needing to have gcp in the project. And it has been tested to work with other softwares. So no, I did not add any GCPs. I did try optimizing, but that does not make a huge difference, because reconstruction is quite perfect right away.