A Probe-Mounted Radar Downward-Looking Mapping Method for Mars Exploration

Limited by Mars's complicated conditions of atmosphere and light, it is difficult to realize all-time and allweather landing guidance based on optical instrument. To solve this problem, we propose a radar downward-looking method, allowing for mapping the surface of Mars in the stage of probe hovering. To this end, we firstly establish an accurate radial downward-looking echo model according to the mapping geometry, breaking through the mechnism limitation of conventional side-looking synthetic aperture radar (SAR). Then, we incooperate the Multiple Signal Classification (MUSIC) method with the proposed model to reconstruct the super-resolution surface map of Mars. Compared with the existing radar imaging methods, the proposed method make up for the blind area, and improve the safe landing capability for the Mars probe in the complex environment. Simulations are given to verify the excellent imaging performance.