A new navigation approach of terrain contour matching based on 3-D terrain reconstruction from onboard image sequence

Abstract

This article presents a passive navigation method of terrain contour matching by reconstructing the 3-D terrain from the image sequence (acquired by the onboard camera). To achieve automation and simultaneity of the image sequence processing for navigation, a correspondence registration method based on control points tracking is proposed which tracks the sparse control points through the whole image sequence and uses them as correspondence in the relation geometry solution. Besides, a key frame selection method based on the images overlapping ratio and intersecting angles is explored, thereafter the requirement for the camera system configuration is provided. The proposed method also includes an optimal local homography estimating algorithm according to the control points, which helps correctly predict points to be matched and their speed corresponding. Consequently, the real-time 3-D terrain of the trajectory thus reconstructed is matched with the referenced terrain map, and the result of which provides navigating information. The digital simulation experiment and the real image based experiment have verified the proposed method.