Wide-baseline stereo vision for Mars rovers

In order to perform localization and navigation over significant distances (up to a few kilometers), it is important to be able to accurately map the terrain to be traversed. Local methods, such as conventional stereo, do not scale well to large distances and prevent longrange planning. In this paper, we discuss wide-baseline stereo techniques for rovers. In wide-baseline stereo, the image pair is captured with the same camera, but at different positions of the rover. While the larger baseline allows improved accuracy for more distant terrain, stereo matching is more difficult for two reasons. First, odometry errors result in uncertain knowledge of the relative positions of the cameras when the images are captured. Second, the change in perspective makes stereo matching difficult, since image landmarks no longer have the same appearance in both images. We address these problems and show test results on real images.