Abstract
This paper proposes a Terrain Relative Navigation (TRN) method for high-precision position estimation at the Moon’s shadowed regions by fusing the camera image and Synthetic Aperture Radar (SAR) data. TRN, which estimates the position of the lander by comparing the preliminary maintained terrain information in a database with the observed terrain, is an effective method to correct the drift errors of IMUs. Optical cameras are mainly used for TRN sensors to observe the terrain, but shadow images do not have enough characteristic points to match with the database. SAR is a form of radar that can generate high-resolution photo-like images regardless of light conditions. In this study, we proposed the use of SAR as navigation sensors and showed its effectiveness.
