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Automatic Generation of a Hierarchical DEM for Mars Rover Navigation
Fengliang Xu, Fei Ma, Rongxing Li, Larry H. Matthies, and Clark F. Olson In Proceedings of the 3rd Interational Symposium on Mobile Mapping Technology, Cairo, 2001. This paper presents techniques for the generation of a hierarchical DEM using descent and rover imagery for Mars mapping and rover localization. During a descending process of a Mars spacecraft, ten descent images may be taken at approximately every half of the altitude. The images can be used to generate an initial DEM of the landing site. We further refine the DEM both in accuracy and resolution to form a five-layer hierarchical DEM, with the resolution ranging from one centimeter in the immediate area of the landing center to one meter in the boundary region about 1 km away from the center. To build the DEM, we employed area-based matching assisted by epipolar constraints and the least-squares matching for refinement. The DEM is generated by using the hierarchical descent images with an increasing sequence of resolutions. The produced hierarchical DEM can be used for an interactive system to assist rover traverse design and for landmark extraction for automatic Mars rover localization. |
