From aerial photographs and different unmanned aerial vehicle images, measurement of land topography, analysis of results and comparison (The study of Haymana Yeşilyurt village)

Unmanned aerial vehicle have been widely used in photogrammetric studies with the development of platform and sensor technology in recent years. The photogrammetric result products produced by the classical aerial photogrammetry work steps can be obtained from images taken with UAVs, especially in areas of a certain size. In this study, automatic matching of photogrammetric images obtained by different platforms belonging to the same area and comparison of measurements by producing dense point cloud is aimed. For this purpose, the aerial photographs obtained by the classical method and the images taken by the rotary wing and fixed wing UAV platforms were used in the application stage. Pix4D and Agisoft software are widely used to process photogrammetric images from UAVs and other platforms. The basic working principle of these software is image matching and dense point cloud based on SfM algorithm. With the aforementioned software, images of fixed and rotary wing UAV platforms were processed and orthophoto was produced with digital surface model and the results were compared. At the same time, aerial photographs taken using classical photogrammetric techniques were processed with the same software and elevation data were compared. Yeşilyurt Village of Haymana District of Ankara Province was chosen as the study area. Geodetic coordinates of measurements obtained from UAV images and aerial photographs were performed in two ways by using GCP and camera positions during flight. GCPs, which are also used in indirect geodesic coordinating, were measured with GNSS receiver using TUSAGA active. GPS measurements taken from the field were used as reference data in the study and direct and indirect geodetic transformation and location and elevation information were analyzed. As a result; It has been evaluated that survey data obtained by classical aerial methods can be obtained by using images obtained from UAVs with high resolution, low cost, fast processing steps and sufficient position accuracy. Furthermore, the results obtained by processing the images obtained from different UAV platforms in Agisoft and Pix4D software accuracy were found to be close to each other.