I have been trying to use the Mavic Pro for quantity survey for the last little while. (6 months).
For the last few years, we have used the Phantom 3 with great success. To this end I thought the Mavic Pro would be just as good, but a lot easier to carry around.
But all of the survey's I have done with the Mavic Pro have greatly exaggerated heights of piles, buildings and vehicles. Initially I thought this was an issue with the survey on the ground, however, I have now had a few sites flown at the exact same time by a different drone, and I am seeing nothing unusual in that survey.
https://puu.sh/B1Mo3/8be8e1e008.jpghttps://puu.sh/B1MBz/8c065367c4.pngAs you can see in these screen shots, the vehicles in the point cloud look extremely tall. In fact my own vehicle is shown to be 4.3m tall. when in reality, it is 2.4m
I get the same result for each pile as well. The peaks are nearly double the height of the real thing.
This specific survey I used 6 GCP's, the entire area was only 170m x 130m. The GCP's were surveyed using an RTK setup with an accuracy less than 3cm.
https://puu.sh/B1MI2/eb785938aa.jpghttps://puu.sh/B1MKw/b1bdc9aabd.png I used a 90% forward and 80% sideways overlap for the flights. There is also lots of area outside the survey zone that was flown.
https://puu.sh/B1MPz/2d7461baa5.png