Assessment of geo-coding and height accuracy of the DEM derived from preliminary data sets of X-band SRTM

Abstract

The first data set of X-band Digital Elevation Model (DEM), derived from Shuttle Radar Topography Mission (SRTM), of GuJarat Earthquake affected area was processed to assess the geo-coding and height accuracy. A detailed Survey of the Study area was carried out using Differential-GPS systems to get accurate control points. Though, it is the first data set processed without Attitude and Orbit Determination Avionics, the geo-coding and height accuracy is good. It is observed that there is an average shift of -1.5 pixels in Latitude and 2.5 pixels in Longitude with 1.5 pixels Standard Deviation (STD). A comparison of SRTM and Ditferential-GPS heights indicates that there is a bias of 7.4 m with STD of 3.4 m. This is in agreement with the height errors reported by the Deutschen Zentrums fur Luft- Lind Raumfahrt (DLR) in Height Error Map (HEM) data set.