Discussion of lunar surface structures based on Chang'E-3 lunar penetrating radar data

Due to the fact that the lunar surface is dry enough, the attenuation of electromagnetic waves in lunar rocks is lower than that in the Earth's rocks. Therefore, radar technology has the advantages of high resolution and large penetration depth in lunar exploration. Radar detection technology is widely used in the lunar exploration process. China's Chang'E-3 and Chang'E-4 probes are both equipped with lunar penetrating radar (LPR), which are used to analyse or detect subsurface features of the lunar, including the dielectric constant, the thickness of lunar regolith and the stratigraphic sequence as well as the geological structure. Based on the research of Chang'E-3 LPR radar, this paper compares different methods for estimating dielectric constants and c alculating the thickness of lunar regolith and sublayers, and then discusses different lunar subsurface geological models proposed by previous publications, in order to better process and interpret the Chang'E -4 LPR data. The results suggest that although the lunar subsurface structure and thickness of the Chang'E-3 landing site are controversial, the thickness of surface regolith is generally recognized as about 1.0 m, and the landing site is thought to have been filled with lava flows from various volcanic eruption events.