月極域探査向け画像照合航法の検討と検証

抄録

In the search for celestial bodies such as the moon, the terrain relative navigation, which estimates the position of a spacecraft using a camera, has been developed. The navigation in the SLIM (Smart Lander Investigation for the Moon), the Japanese moon investigation project, extracts craters from images taken by the camera and compares them with a crater map which consists of the positions and radiuses of the craters. However, the sufficient number of craters for this navigation method may not be observed in the lunar polar region where the solar altitude is low. Therefore, we have considered a new navigation method, which directly compares the camera image with a lunar surface photo map prepared in advance, by combination of the template matching and the least squares matching techniques. Using several lunar polar images in which more than half of the field of view is covered by shadow, we have confirmed effectiveness of the method by an evaluation experiment that shows the required accuracy of position estimation was provided.