Stereo Evaluation of ALOS/PRISM Data on ESA-AO Test Sites - First DLR Results

Abstract

DLR's Remote Sensing Technology Institute has more than 20 years of history in developing spaceborne stereo scanners (MEOSS, MOMS) and the corresponding stereo evaluation software systems. It takes part in the ESA/JAXAAO Program to evaluate the performance and potential of the three-line stereo scanner PRISM (Panchromatic Remotesensing Instrument for Stereo Mapping) and the multispectral imaging sensor AVNIR-2 onboard the Japanese satellite ALOS as a principal investigator. French (near Marseille), German (near Munich) and Spanish (near Barcelona) test sites are proposed. In this paper, the process of direct georeferencing according to JAXA is shown and the results are presented. The geolocation accuracy improved immensely. For the newest dataset, ground control points (GCPs) are no longer obligatory, but useful. Rational polynomial coefficients (RPCs) are generated using DLR software. Thereby, oscillations in the orientation angles in the order of up to one pixel on the ground occurred in the older datasets. These oscillations can not be compensated by an RPC-based approach, however, in the newer dataset, they are no longer existent. The coregistration of forward, nadir and backward view is examined and DSMs are generated and analyzed.