TERRAIN PARAMETER RETRIEVAL USING IRS 1C/1D STEREO DATA IN CONJUNCTION WITH DIFFERENTIAL GPS MEASUREMENTS

In the past few decades due to enormous development in satellite photogrammetry, more opportunities are available to have a stereo pair from the space borne missions. Indian Remote Sensing satellites (IRS 1C/1D) with its steering capacity to ± 26º provides an opportunity to satellite stereo analysis. The present study was aimed at framing the methodologies for DGPS survey, data analysis, establishment of GCP coordinates and stereo data analysis. Two study areas were selected corresponding to moderately undulating to hilly terrain. DGPS survey was carried out to establish GCPs. About 64 GCPs were established altogether at two different sites. DEM and Ortho images were generated and validated using DGPS measurements. An attempt was also carried out to automatically extract drainage networks and was validated using those available at 1: 50000 toposheets. For moderately undulating terrain, DEM and Ortho images have been generated using Eight GCPs. The RMS error of GCPs were 8.13 m, 16.31 m and 8.33 m along Easting, Northing and Elevation respectively and that of 5 check points were 20.02 m, 17.10 m and 17.97 m respectively. Morphometric analysis of the drainage pattern has also been carried out by visual comparison with those in the topographic map and overlying on the Ortho image. Coordinate comparison on ortho resulted in 7.932078 m and 14.86542 m RMSE at latitude and longitude respectively. For hilly terrain, 6 GCP’s, 102 tie points and three check points were used to assess the model accuracy and for generation of DEM. RMSE (planimetric) of the model for 6 GCPs and 2 check points are respectively 4.25m; 3.78m and 15.30m 22.9m at Easting and Northing respectively. DEM accuracy at GCPs (5) an