Georeferencing X Y (AND Z) with GCPs in QGIS

Question

I have GCPs recorded to centimeter precision in lat, long, and elevation.

I want to georeference my UAV-photogrammetry-generated GeoTIFF and DEM with these GCPs (since the GPS on my UAV is only accurate to 5 meters).

I have only found tutorials describing how to use the "Georeferencer" in QGIS to georeference a GeoTIFF in XY with GCPs via their lat/long coordinates.

As this will definitely benefit the horizontal accuracy of my model by correcting any global horizontal warping of the GeoTIFF, it seems the elevation data from my GCPs will be unused.

• Is there a way to also incorporate the elevation data from the GCPs?

  I imagine my DEM would benefit from the elevation data of a dozen properly placed GCPs (in the peaks and valleys).

• Is there an algorithm in QGIS to effectively "warp" or "stretch" the DEM in the "3D space"?

  I imagine that the DEM could do a "best fit" and connect through the elevation points of the GCP coordinates while smoothly interpolating the curvature in-between based on the original DEM data?

Answer 1

I haven't found a solution directly in QGIS but with AgiSoft is possible to implement the solution which you are looking for!