Correction of distorted high definition DEM generated by photogrametry using Global Mapper

hristijan_anch

Hi,

I have generated a DEM (0.1 m) using photogrametry software with 47 reference points bought from the official state Cadaster agency. Unfortunately the DEM was not correct. I`ve used the Global Mapper rectification tool for the horizontal alignment to an ortho-photo of the area and the result was fantastic. But still, the elevation data is corrupted. Using the GM combine/compare tool, there is -36 m result in the western edge, and +18 on the eastern compared to the elevation grid generated on the 20 m point grid. I tried comparing to other DEM produced by satellite surveys but the differences are relatively the same.

Is there a way to do a DEM elevation correction to the values of other correct DEM or point clouds?

I was thinking on searching for the elevation differences using Subtraction (Difference) - Signed function, then generation something like a mirror over ideal horizontal axis of the combined elevation grid, and then adding these mirrored new values to the 5m, 10m, 20m, 30m resolution DEM using Addition function.
I tried the Addition function using the Combined elevation grid on some of the satellite images but I get the new Combined elevation grid with the bad resolution of the satellite images, not from the 0.1 m resolution of the model.

The high definition DEM is needed for monitoring activities of a protected area.

Thank you very much.