Generation and validation of the interferometric SAR DEMs from TanDEM-X data for Gangotri and Hamtah glaciers of Indian Himalayas
TanDEM-X SAR mission was launched in June, 2010 with an aim to generate high resolution global DEMs of HRTI-3 specification. Considering this, it is very important to evaluate the accuracy of the DEM generated using TanDEM-X InSAR data over the rugged terrains of Indian Himalayas. This paper presents the results of an evaluation study of the DEMs generated through interferometric technique using TanDEM-X data over two Indian Himalayan glaciers viz. Hamtah and Gangotri. The two generated DEMs have been compared with the corresponding accurate Differential Global Positioning System (DGPS) values. On the basis of comparison of the elevation values between TanDEM-X DEM and DGPS data, it is observed that the Hamtah and Gangotri glacier DEMs show RMSE values 7.0 m and 8.2 m respectively. To evaluate the performance between TanDEM-X DEM and SRTM DEM, the SRTM DEM of the Hamtah glacier has also been compared with the DPGS points of Hamtah glacier and found to have a RMSE of 13.5m. Overall, the obtained results indicate that the generated TanDEM-X DEMs are of superior quality.