Coupled feature matching and INS for small body landing navigation

A method for spacecraft autonomous landing on the asteroid is presented in this paper bases on fusion of feature points database matching combined with inertial navigation. Feature points can be extracted from fly-around images by PCA-SIFT algorithm while the feature points database can be built. At the beginning of landing, the position and attitude of a spacecraft can be estimated by using feature points matching and 3D small body shape. At the terminal landing, takeing the mosaic image as virtual navigation map and selecting appropriate points, the 6DOF states of the spacecraft can be estimated by the combination of optical navigation and INS. And then a combined optical inertial navigation approach is given and the position of current image in the mosaic image is calculated by using the selected points matching. Finally, the navigation accuracy and error effect are analyzed and the validity of the proposed scheme is confirmed by computer simulation.