Acucuracy evaluation of orthophoto maps obtained by UAV systems

Unmanned Aerial Vehicles (UAV), which is one of the most important gains of the developing technology, was firstly used for military purposes. After a while later, UAV became an important part of our daily life. In addition to the ability to produce three-dimensional spatial information with the UAV, it also provides less labor, time and cost advantage compared to conventional measurement methods which are playing an important role in the spread of UAV usage. UAV systems, whose usage are becoming widespread and diverse day by day, are in a continuous development to meet the high accuracy requirements, especially for surveying activities. For this reason, UAV hardware and software features are also constantly developing. It is thought that examining the benefits provided by the use of GNSS technology that is the one of surveying equipments in UAVs, is important in terms of engineering projects and the choice of measurement devices to be used in these projects. In this thesis study, firstly, the accuracy comparisons of the data sets based on the UAV with GNSS-RTK and the UAV without this feature were studied. Accuracy analysis of the data sets processed by Pix4D Mapper and Agisoft FotoScan photogrammetry software were also utilized. As a result of analysis, it was seen that the horizontal and vertical accuracy values obtained for the UAV data with GNSS-RTK were better than the horizontal and vertical accuracy values obtained for other UAV data. When the software were evaluated among themselves, it was seen that the horizontal and vertical accuracy of the data sets obtained with Pix4D Mapper software was better. While Agisoft FotoScan software gives better results in horizontal position accuracy of data sets based on UAV without GNSS-RTK, Pix4D Mapper software gives better results in vertical position accuracy of those.