The presented UAV error analysis used the same test bed for evaluation
of its measurement error. The UAV flew at multiple different
heights. In the earlier experiments the camera attached to the UAV
took 99 photos at 30 m height at a ground resolution of 0.7 cm per
pixel and 49 photos at 50 m at a ground resolution of 1.2 cm per pixel.
The point cloud resulting from the images at 30 m height was selected
because it had initially a higher ground resolution. Later experiments
showed, however, that a flying altitude of 50 m is preferred over
lower flying heights due to the fact that individually taken photos
have more overlap with each other.