<title>Near-range stereo for Mars landing site reconstruction</title>

摘要

Within the European Mars Express Mission to be launched 2003 the Beagle2 Lander will foresee the access to stereoscopic views of the surrounding Martian surface after touchdown. For scientific purposes the necessity for a high resolution three dimensional (3D) reconstruction of the landing site is evident. A lander vision subsystem capable of reconstructing the landing site and its vicinity using a stereo camera mounted on the robotic arm of the lander is used therefore. Knowledge about the geometric camera features (position and pointing with respect to each other, position and pointing with respect to the lander, intrinsic parameters and lens distortion) are determined in a calibration step on ground before takeoff. The 3D reconstruction of the landing site is performed after landing by means of stereo matching using the transmitted images. Merging several stereo reconstructions uses the respective robotic arm states during image acquisition for calibration. This paper describes the full processing chain consisting of calibration of the sensor system, stereo matching, 3D reconstruction and merging of results. Emphasis is laid on the stereo reconstruction step. A software system configuration is proposed. Tests using Mars Pathfinder images as example data show the feasibility of the approach and give accuracy estimations.