Evaluation of DEM, Orthophoto Generated from Cartosat-1 with its Potential for Feature Extraction and Visualization

Abstract

The present study evaluates the accuracy of Triangulation, Digital Elevation Model (DEM) and orthoimage generated by Cartosat-1 data by using Rational Polynomial Coefficient’s (RPC’s) provided with the Cartosat-1 satellite stereo (PAN) data. The study area is taken as Jaipur city, Rajasthan. The data acquired over Jaipur, on 18 May’ 2005 was analysed. The stereopair comprises of terrain ranging from plain area, agriculture fields, urban area, waterbody and Aravalli hill range. A Differential Global Positioning System (DGPS) survey was conducted to collect ground control points (GCPs) for satellite triangulation, DEM generation, orthoimage generation and subsequent analysis for accuracy assessment. Eighteen GCPs were measured through DGPS survey. Twelve GCPs are used for triangulation and six GCPs were used as check points. The overall RMSE for satellite triangulation is 0.753 pixel. Horizontal accuracy of 2.08 m and 1.74 m is achieved in X and Y direction, respectively. The vertical accuracy of 3.72 m has been assessed separately also by using independent check point in highly varying terrain.