I did a drone survey on the beach zone in south Olso. After analyzing the dataset, I found the elevation of output DSM ranged from 39-40 m. It should be 0-1 m relative to sea level. The base receiver was Reach RS2, the rover receiver equipped on the drone was GNSS receiver housing for installation on DJI Matrice 210. See more info. from the following link (TOPODRONE DJI Enterprise PPK Upgrade Kit + Sony RX1R II 42Mp).
I enquired the supplier of Reach RS2 about this issue, they told me I should set the coordinate system of Reach RS2 as ETRS89+NN2000 height (EPSG: 4258+ EPSG: 5941). If I set the coordinate system as they told, in the pix4dmapper (Select Coordinate System), I can choose the coordinate system of EPSG4258 in the Known coordinate system-From EPSG. But I can not choose the NN2000 height in the vertical coordinate system. Could you tell me how I can choose my vertical coordinate system because only MSL, Geoid Height Above WGS 84 Ellipsoil, and Arbitrary available?
Or do you have other suggestions about my coordinate system setting? Appreciated it very much if you can give me any feedback.