Heighting Accuracy Of Spot Imagery

Abstract

The SPOT imaging system is the first sensor with stereoscopic capability and global continuous coverage. Stereopairs with overlap and base to height ratio suitable for the extraction of height information with reasonable accuracy can be obtained. This paper summarises the results of an investigation carried out to determine the accuracy of heights derived from SPOT stereoscopic data and to assess the potential of contouring and digital terrain modelling. A stereopair, covers an area in the South West of Sinai was used to form a stereoscopic model, on the WILD-BC-2 analytical plotter. Ground control points were derived from 1:50000 topographic maps. A digital elevation model with one-kilometer spacing in the two directions and 1:100,000 scale topographic map with 20 m contour interval were produced on the BC-2. Root mean square errors in heights were computed and found to be ± 11.5 m and ± 9.4m before and after applying filtering respectively.