I’ve done a trial drone survey, with a DJI Mavic 3E, of an area local to me with 4no GCPs. Two of these GCP’s were later surveyed with a total station with the correct scale factor to give oc-ordinates in the correct co-ordinate system and accurate heights. These two GCPs were given weights of 50.000 and position accuracy of 10mm in all 3 axes, the other 2 GCPs were weighted 10.000 and accuracy of 50mm in all 3 axes (these 2 GCPs had been surveyed with GPS RTK only for 5 minutes)
I’ve imported the images and GCPs into Reality Scan 2.1.1, postioned the GCPs in the images, run an alignment and this returns slightly adjusted positions for all the GCPs. The first 2 surveyed with total station are adjusted by less than 1mm, the other 2 are adjusted by approx 15mm.
However when I export the point cloud, the height value on the adjusted GCPs appears to be slightly different to the height values of the point cloud, some are up to 30mm lower than the cloud and some are upto 30mm higher than the cloud.
I’ve tried changing prior pose settings on the images (unknown, position, position and orientation & locked) however none of these seem to make the point cloud height values match the adjusted GCP height values.
Am I missing something to make the point cloud match the adjusted GCP ? Any assistance would be appreciated
Point cloud heights in white / adjusted GCP value in green below - distance between point cloud points approx 65mm
