Relative pose estimation of a lander using crater detection and matching

Future space exploration missions require precise information about the lander pose during the descent and landing steps. An effective algorithm that utilizes crater detection and matching is presented to determine the lander pose with respect to the planetary surface. First, the projections of the crater circular rims in the descent image are detected and fitted into ellipses based on the geometric distance and coplanar circles constraint. Second, the detected craters are metrically rectified through a two-dimensional homography and matched with the crater database by similarity transformation. Finally, the lander pose is calculated by a norm-based optimization method. The algorithm is tested by synthetic and real trials. The experimental results show that our presented algorithm can determine the lander pose accurately and robustly.