Lunar terrain parameter estimation using LMS for hazard detection and safe landing

This paper presents how to estimate two parameters: slope and roughness representing lunar terrain quality for HDA (Hazard Detection and Avoidance) of lunar lander. Robust plane fitting technique based on LMS (Least Median Square) is applied to standardized DEM (Digital Elevation Model) from LIDAR (Light Detection and Ranging) sensor measurement in order to estimate the parameters. Since a number of hazards exist on the lunar surface such as craters, rocks and cliff, which are able to damage lunar lander, it is important for HDA system to precisely detect hazards and select safe landing site by meticulously characterizing terrain condition. For this reason, out research has been conducted using various sensors such as camera, infrared sensor, LIDAR sensors for HDA algorithm. Because sensor measurement can be processed in high speed relative to optical image and obtained at any light condition, it is an effective way to perform hazard detection and avoidance landing based on the LIDAR measurement. Therefore, it is confirmed that safe landing site can be extracted based on the parameters through simulation in this paper.