Comparative analysis of reflection characteristics of lunar penetrating radar data using numerical simulations

Abstract

The Moon and most extraterrestrial objects are lacking in water; thus, electromagnetic waves can penetrate deep into the ground and bring some structural information about the regolith and surrounding rocks. As an important assistant to the existing payloads, ground penetrating radar (GPR) is particularly suitable for deep space exploration, which is feasible and necessary for detecting the subsurface structures (mainly associated with the dielectric permittivity variations) of extraterrestrial objects. Unfortunately, there are not enough reference GPR profiles or drills on the extraterrestrial objects to constrain the acquired data. Here, we construct some typical models and perform numerical simulations. To make the results reasonable, various factors are considered, including the type, scale, and location of the abnormal bodies. Then, we review the reflecting phenomenon under the ground and perform comparative analyses on the reflection characteristics of different models. Finally, we present some criteria for identifying different reflectors using critical patterns of reflections. The configuration of our numerical experiments is comparable to that of the lunar penetrating radar onboard the Yutu-1 and -2; thus, the results would be reliable to support the geological interpretation of detected records as well as possible GPR detection on extraterrestrial objects in the future. This work is helpful for recognizing the reflection characteristics of the observed GPR data and would be beneficial to uncovering more critical details of subsurface structures.