Accuracy validation and bias assessment for various multi-sensor open-source DEMs in part of the Karakoram region

ABSTRACT

The present study evaluate horizontal and vertical accuracy of seven open-source digital elevation models (DEMs) having moderate-to-high resolutions viz. 30 m Shuttle Radar Topography Mission (SRTM1), Advanced Spaceborne Thermal Emission and Reflection Radiometer Global DEM (ASTER GDEM), Advanced Land Observing Satellite World 3D (AW3D30), and Cartosat DEM (CartoDEM), 90 m TerraSAR-X add-on for Digital Elevation Measurement (TanDEM-X), 12.5 m terrain corrected Phased Array L-band Synthetic Aperture Radar (PALSAR) from Advanced Land Observing Satellite (ALOS) and 8 m High Mountain Asia (HMA) over the rugged mountainous terrain of the Karakoram region. Horizontal accuracy (specified in x and y) assessed by referring photogrammetrically generated master DEM from Cartosat-1 revealed AW3D30 as the most consistent DEM with a slight shift of +2.80 m and −4.89 m in x and y direction, respectively. However, vertical accuracy analysis showed that both HMA and AW3D30 DEMs are quite close to each other with MAE of 3.01 m and 3.46 m, RMSE of 5.6 m and 7.5 m, and NMAD of 4.09 m and 5.5 m, respectively. We also examined the influence of slope on DEM errors and associated elevation-dependent bias over non-glaciated surface which can be valuable input for geodetic mass balance estimations.

Acknowledgments

The authors are thankful to Director SASE for the technical support. We would like to acknowledge various institutions for providing DEMs and LIDAR data. A special thanks to Etienne Berthier (LEGOS, CNRS) for the technical discussion. This work was carried out under DRDO project ‘Him-Parivartan’.

Declaration of interest

No potential conflict of interest was reported by the authors.