Underground Characteristics Extraction Method Using the Fully Polarized Subsurface Penetrating Radar of Zhurong Rover

The Martian rover Zhurong represents the first deep-space exploration rover to be equipped with full-polarimetric ground-penetrating radar (GPR). This radar collects multipolarization data that capture the rotation of the electric vector, thereby providing insights into the type, surface roughness, and dielectric properties of subsurface objects. However, most studies have relied on conventional analysis methods, thereby failing to exploit the full potential of all four data channels. In this study, we utilize simulated 3-D polarimetric data derived from subsurface models representative of the mission’s landing area, which comprises the Martian atmosphere, surface soil, subsurface ice, rocks, and bedrock layers. The simulation results facilitate an analysis of the scattering characteristics of subsurface targets, such as stones and fractures. We propose a false-color imaging and processing method that enhances radar image quality and improves the precision of permittivity estimation to 90%. Furthermore, the scattering spectrum derived from Freeman decomposition is employed to classify various subsurface structures while providing information on their types, sizes, and dielectric properties. Ultimately, the proposed method is applied to analyze the radar data acquired by the Zhurong rover on Mars.