Two Algorithms and Error Analysis for 3D Terrain Reconstruction of Small Body

This paper presents the problem of reconstructing the 3D terrain model for landing of small body spacecraft, in order to approach and land on a small body successfully. We propose an on-line terrain modeling using image sequence provided by an on-board camera. The recursive structure from motion algorithm and the orthography factorization algorithm are proposed to recover the depth maps. The application range and reconstruction precision of the two different methods are demonstrated by the experimental results. It is shown that the has recursive structure from motion algorithm has a higher accuracy, while the orthography factorization algorithm is more robust.