Assessment and Comparison of DEM Generated Using Cartosat-1 Stereo Pair Data for Hydrological Applications

Accurate depiction of the topography of Earth’s surface is an essential requirement to produce photogrammetric products like DEM and ortho-images as they are used in hydrological modeling, hydrodynamic modeling and morphological studies. The overriding objective of this study is to generate a high-spatial resolution DEM using Cartosat-1 stereo pair data and ground control points obtained from Differential Global Positioning System. Comparison of the DEM generated from Cartosat-1 stereo pair and publicly available DEMs was also carried out in this study for hydrologic applications. The generated DEM using the Ground Control Points (GCPs) returned a low RMSE value of 0.18 pixels during block triangulation indicating the model error to be much less than one pixel. From the comparative result of vertical accuracy, it was found that the DEM generated from Cartosat-1 stereo pair data performs better followed by SRTM, ALOS PALSAR and ASTER with RMSE values of 2.91, 5.21, 5.69 and 6.17 m, respectively. In the watershed demarcation and stream network delineation analysis, the results obtained from the Cartosat-1 stereo pair DEM and ALOS PALSAR were found to be more accurate than SRTM and ASTER. This study clearly indicates that the high-resolution DEMs generated using the bundle GCPs approach produced a better result with higher accuracy.