Bistatic Radar Detection of Water Ice Deposits in Lunar Polar Regions

Abstract

Deep space bistatic radar facing some challenges in planetary exploration，including rapidly varying observation geometry，extremely low signal-to-noise ratios，and difficulty in calibrating channel gain and phase due to the absence of onboard calibration sources. To address these issues, a bistatic radar terrain inversion system tailored for deep space applications was developed. Using the SPICE （Spacecraft Planet Instrument C-matrix Events） toolkit and focusing on echo data acquired under near-backscatter conditions. The system integratd geometry modeling，data calibration，and multiparameter inversion of surface characteristics. The analysis demonstrates that the proposed system successfully extracted electromagnetic indicators associated with potential water-ice deposits in the lunar south polar region，including enhanced echo power，locally elevated circular polarization ratios （CPR），reduced dielectric constants，and disturbed cross-spectrum phase behavior. These combined features support the possible presence of polar water-ice deposits. The results verify the effectiveness of deep space bistatic radar for surface and material inversion and provide a scalable technical pathway for future bistatic radar applications in deep space missions.

Keywords

terrain inversion / detection of water ice deposits / bistatic radar / SPICE