ICESat-2 for evaluating space-borne and national digital elevation models across forest and non-forest landscapes in Kastamonu, Türkiye

Abstract

Technological advancements have revolutionized the production of Global digital elevation models (DEMs). Today, there is an ever-increasing availability of global DEMs for scientific applications. The 12 m TanDEM-X, 30 m TanDEM-X Edited, 30 m Copernicus, and 30 m FABDEM global DEMs, along with the 5 m Turkish national DEM were compared in this study. While the global DEMs result from interferometric synthetic aperture radar, the Turkish DEM is produced by stereo-photogrammetry. The assessment was conducted in forested and non-forested settings. The validation was done using the Ice, Cloud and Land Elevation Satellite-2 (ICESat-2) LiDAR. Generally, FABDEM emerged as the most reliable DEM, achieving the best performance in three settings (whole area RMSE: 2.93 m; forest RMSE: 3.98 m; >70 % canopy closure RMSE: 4.31 m). In contrast, the Turkish national DEM outperformed the other DEMs in two settings (non-forest RMSE: 1.54 m; <70 % canopy closure RMSE: 2.83 m). Global DEMs with improved accuracies may soon replace authoritative national DEMs for various applications.