Operational Determination of Tie Points and Bundle Adjustment of Hrsc Images of the Mars Express Mission

The pushbroom scanner HRSC (High Resolution Stereo Camera) onboard the European Mars Express mission is orbiting the planet Mars since January 2004 and delivers stereoscopic imagery with five panchromatic and four colour channels. This paper describes the process of improving the exterior orientation of the HRSC which is needed in order to derive high quality products such as high resolution Digital Terrain Models (DTMs) and ortho image mosaics from the data. The systematic photogrammetric processing for improving the exterior orientation is divided into two steps: First, a large number of tie points have to be automatically determined in the images using digital image matching. Second, a bundle adjustment is carried out using the globally available MOLA (Mars Orbiter Laser Altimeter) DTM as control information. The developed approaches of the matching and the bundle adjustment will be described in this paper. After that, the performance of both methods will be evaluated with respect to point accuracy and consistency with the MOLA DTM on the basis of 45 test data sets. * Corresponding author.