Evaluation of Cartosat 1 geometric potential

The results of Cartosat 1 (IRS P5) imagery investigation held in terms of participation in ISPRS and ISRO Cartosat 1 Scientific Assessment Programme (C-SAP) are presented. Different images orientation methods were tested; the recommended one is bias-and-drift adjusted RPC model. In the case of single stereopair or single scene, four well-distributed reliable ground control points is enough to achieve sub-pixel orientation accuracy (evaluated using numerous check points). In the case of block of stereopair, the number of ground control points required per stereopair can be diminished by replacing part of them by tie points measured in the stereopairs overlap (four-times overlapping area). The derived DEM accuracy is 2 m RMSE for flat area and 7 m RMSE for mountainous one (as compared to reference DEMs). The orthoimagery created meets the geometric accuracy requirements t