3D reconstruction 3D-model BIM GEOBIA GNSS RTK Technology: general issues UAV UAV images UAV photogrammetry accuracy accuracy assessment building maintenance construction planning convolutional neural network (CNN) correlation corridor mapping deep learning drone elevation forests generative adversarial network (GAN) ground control points (GCP) image overlap image-based reconstruction lidar monoscopic mapping multiscale classification multispectral imaging nutritional analysis optimal harvest time