An Assessment of CartoDEM v1 over National Capital Region of India

Farhat Rafiq

doi:10.3759/jowrem.v3i3.1880

Abstract

The most reliable and common source of elevation information for a given region has always been topo-sheet maps. However, other sources of elevation are now freely available with the advancement in the technology. SRTM DEM and ASTER DEM are the best examples of such freely available elevation sources. Still there is constantly a demand of better elevation data among the users. Recently, National Remote Sensing Center, India released CartoDEM v1. It is freely available with a horizontal resolution of 30 m and covers pan India. It is always challenging to ascertain the quality and accuracy of freely available DEMs. This paper, over National Capital Region (NCR) of India, assesses the quality of the CartoDEM v1 using 127 surveyed spot-heights and bench-marks captured from 1:50,000 scale SOI topo-sheet maps and carries out a comparison with SRTM DEM v4 and ASTER DEM v2. It is demonstrated that mean error is 1.34 m and absolute RMSE of CartoDEM is 2.83 m. The relative RMSE with SRTM DEM is 2.77 m and ASTERDEM, is 3.34 m. The trend of hydrological sinks in CartoDEM is similar to SRTM DEM and ASTERDEM. The drainage network delineated shows better match with channels in actual on ground and catchment divides are clearly demarcated by CartoDEM. The achieved results develop confidence in the quality of CartoDEM over NCR in India and opens alternatives to use CartoDEM over publicly available SRTM DEM and ASTER DEM. Also, it opens avenues for research either on version 1 or on other versions of CartoDEM for its better usability over Indian region.