Robust Landmark Matching Method for Visual Navigation Near Small Bodies

A robust and efficient landmark matching algorithm was proposed in this paper to deal with the extreme environment near the target asteroid. First, the matching error of the landmark generated by the SPC (StereoPhotoClinometry) technology was analyzed, and the influence of landmark position error and cameras’ pose error on the matching results was discussed. Then, based on the error analysis, the optimal landmark points were selected, and a weighted normalized cross-correlation (WNCC) algorithm was proposed to obtain accurate matching results robustly and efficiently. Finally, high-fidelity synthetic image sequences were generated to compare the performance of WNCC and the widely used NCC (Normalized Cross-Correlation) algorithm in the previous asteroid missions under a wide range of image scales, viewing geometries, and lighting conditions. The numerical results demonstrate the advance of the proposed method in terms of efficiency, robustness, and accuracy.