Accuracy Assessment of the ICESat-2/ATL06 Product in the Qilian Mountains Based on CORS and UAV Data

Abstract

Ice, Cloud and Land Elevation Satellite-2/Advanced Topographic Laser Altimeter System 06 (ICESat-2/ATL06) data can be widely used for various applications, such as monitoring changes in glacier thickness. In this article, we use field surveys based on continuously operating reference system (CORS) and unmanned aerial vehicles (UAVs) to verify the elevation accuracy of the ATL06 product. A total of 208 ATL06 footprints were selected for an accuracy assessment by obtaining 348 CORS global positioning system (GPS) measurements and deriving a digital elevation model (DEMs) from 2683 UAV images in four experimental areas with different terrain and landform types in the Qilian Mountains, China. The experiments show that ATL06 data have very high vertical accuracy and horizontal positioning accuracy; the average root-mean-square error (RMSE) yielded by CORS is 0.0846 m, and the corresponding RMSE yielded by the UAV data is 0.1517 m. Furthermore, the positioning accuracy was also affected by the terrain slope.