COMPARISON OF TERRESTRIAL BASED LIDAR WITH UAV PHOTOGRAMMETRY WHEN SURVEYING ROADS IN YAKUTIA

Abstract

Currently, cartography and remote sensing are rapidly developing in connection with the emergence of various modern technologies. GNSS technologies made it possible to determine the location of an object in space with an accuracy of the rst centimeters, unmanned aerial vehicles (UAVs) made it possible to obtain aerial photographs of the area at different times and signi cantly reduced the time spent on eld research, LiDAR made it possible to survey the area with an accuracy of millimeters. In order to monitor geocryological processes on highways, in the summer of 2021, we surveyed areas with a terrestrial based LiDAR (TBL) Trimble TX8 and with UAV a DJI Phantom 4 Adv RTK/PPK. On the investigated sections on the roadbed, subsidence was observed, which form an undulating surface on the road. The reason for the formation of such a surface was the thawing of underground ice and the formation of the formation of subsidence microrelief - byllars. These subsidence landforms have a distinct polygonal pattern. A comparative analysis was carried out in terms of time consumption and shooting accuracy. As the analysis showed, at all stages, the surveying from the TBL took twice as much time. Despite the large time costs, the most important and huge advantage of the TBL over the UAV was the high acquisition accuracy, close to the real values of the relief. Depending on the goals and objectives, these survey methods can be used both individually and in combination, where they perfectly complement each other. At this stage of the study, we received primary data on the surface for the annual monitoring of the roadway subsidence.