I missed the part in that journal article explaining why they lost control of their drone.
I missed it because the paper isn't about drones crashing at all.
It's about the difficulty shooting high quality images through sun glare on the water's...
I think another piece of information missing is whether or not the camera flipped down for the landing; I believe the camera, in addition to the VPS, is used for precision landing.
I believe it was the plain, solid, dirt area that was the problem with no strong identifying marks to show how the align the drone for landing. It arrived overhead like it was supposed to do but the area was not identifiable as unique.
My...
It's important to identify the problem. Is the RTM that failed or precision landing that failed. In the case of the OP I believe that RTH functioned properly; it was precision landing that failed as the landing area was not well identified...
I always liked RTH; it's a great feature. But, you need to make sure your take off point and area within about a 50-foot diameter circle have very clear and distinguishing marking. A clear area without such marking will complicate the landing...