As a result a total of 105 trees out of 113 (correctness of 93 %) trees could be detected correctly. Eight trees could not be detected. The main reason for that is a situation where low trees are located next to dominant ones and therefore stay rather small. Although planted at the same time these trees show height differences of up to 8 meters in relation to the dominant neighbouring trees. An other reason for undetected trees can be a skew growth of a tree, the crown ends up being right next to an other one and can not be separated anymore.