COHERENCE ANALYSIS OF DSMS GENERATED BY MULTISPECTRAL RTK AND RGB NON-RTK UAVS' SIMULTANEOUS DATA

Abstract

In the last decades, unmanned aerial vehicles (UAV) became one of the most demanded remote sensing technologies with the advantage of rapidly and periodically achievable low cost, high resolution, and highly accurate data. Day by day, the technological level of UAVs is improved by the integration of novel instruments. Major novel instruments are multispectral (MS) cameras and real-time kinematic global navigation satellite system (RTK GNSS) receivers. While MS cameras enable much better land cover classification performance, RTK GNSS receivers offer centimeter-level UAV positioning accuracy without needing ground control points (GCP) and facilitate the fieldwork before the flights. In this study, the coherence of digital surface models (DSM) generated by MS RTK and RGB non-RTK UAVs' simultaneous data was investigated with model-based comparison analysis in a vegetation-dominant study area. During the analysis, GCP-supported and higher resolution non- RTK UAV DSM is appointed as the reference model. The results demonstrated that the horizontal coherence of the DSMs is around +/- 1 cm and the vertical coherence is around +/- 70 cm as standard deviation. The causes of vertical accuracy loss in MS RTK DSM are interpolation effect due to lower resolution point cloud and difficult high vegetation land cover, and the limited positioning potential of RTK GNSS.