International Symposium on Applied Geoinformatics (ISAG-2019), İstanbul, Türkiye, 7 - 09 Kasım 2019, ss.1-6
Nowadays, one of the most popular measuring platforms, increasingly applied in many applications is Unmanned Aerial Vehicles (UAVs) that can carry a variety of payloads, are automatically or the remote control system operated with the existing power system. UAVs provide high resolution data with photogrammetric flight plans realized with various sensors. Therefore, UAV have begun to be used as alternatives with the advantages of low cost, time, high spatial and temporal resolution images in data production. In addition, UAVs allow data to be obtained where physical access is difficult or impossible, so the UAV can be used in many different industries and studies; such as agriculture, forestry, energy, mining, construction, archaeology, architecture and security. The data produced by UAVs, which is orthophotos, DSM, point clouds, is an alternative to classical measurement methods that provide high accuracy data production with high geometric accuracy. In this study, it was aimed to compare the spatial and volumetric accuracy of a small size object extracted from the orthophotos, the Digital Surface Models (DSM) and point cloud data generated as a result of UAV flight plans at different altitudes. As UAV flight altitude, 10m, 40, 70m and 100m flight altitudes were determined and UAV flights were performed and images were obtained. In the study, ground control points (GCP) were acquired by RTK-GPS (Real-Time Kinematic) and integrated into the system for producing high-accuracy data. When the comparison among the data produced for different altitudes and the actual values was done, it is observed that there is deformation on the shapes of the objects as the flight altitude increases. It is also seen that the surface lengths and the area values obtained in two dimensions are closer, i.e have small differences. In addition, the accuracy of volumetric values obtained from the three-dimensional DSM and point cloud data decreases as the UAV flight altitude increases.