Accuracy Assessment of TanDEM-X 90 m Digital Elevation Model In East of Malaysia Using GNSS/Levelling

摘要

The main objective of this study is to assess the accuracy of various Global Digital Elevation Model (GDEM) from different open sources data. All the GDEMs were evaluated using GNSS Ground Control Point (GCP) and leveling height from mean sea level (H_msl) at 45 benchmarks around Sabah and Sarawak. The overall vertical accuracy shows the TerraSAR-X add-on for Digital Elevation Measurements (TanDEM-X 90m) DEM consistent well with the Mean Sea Level height with Root mean Square Error (RMSE) of Shutter Radar Topographic Mission (SRTM), TanDEM-X 90m, ALOS World 3D - 30m (AW3D30) and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is ±4.721m, ±3.140m, ±4.207 and ±9.412m, respectively. However, the vertical accuracy for AW3D30 is found better than TanDEM-X 90m with RMSE of ±3.831m, followed by TanDEM-X 90m DEM, SRTM and ASTER when the evaluation is made with orthometric height derived from GNSS GCPs. In overall, TanDEM-X and AW3D30 can be considered the best GDEM for scientific studies in East of Malaysia (Sabah and Sarawak).