Sensitive to permittivity differences, lunar penetrating radar (LPR) can detect stratification due to material property differences in a medium. We examined the subsurface structures of Von Kármán crater within the South Pole-Aitken (SPA) basin on the farside of the Moon using LPR data obtained by the Chang'E-4 mission. Various distinct strata with depth are clearly recognized, consistent with multiple periods of intermittent lava flows, paleo-regolith, and crater ejecta. Numerous concave and arc shape structures observed at various depths are consistent with buried craters and broken rocks, indicating that the ancient lunar surfaces which are currently buried by up to 30 m deep in Von Kármán, as well as the current surface, suffered numerous impacting events. An imaged subsurface thick paleo-regolith infers a quiescent period with low volcanic activity within the Von Kármán crater. Following the quiescent period (shallower in the profile), a relatively young period of volcanism in the Von Kármán crater is inferred. The mapped stratigraphy and chronology of these events present a self-consistent history of the Von Kármán crater within the SPA, which suggests connections to events on the lunar nearside.

由于对介电常数差异敏感，探月雷达 (LPR) 可以检测由于介质中材料特性差异引起的分层。我们使用嫦娥四号任务获得的 LPR 数据检查了月球背面南极-艾特肯 (SPA) 盆地内冯卡门陨石坑的地下结构。各种不同深度的地层清晰可见，与多期间歇性熔岩流、古风化层和火山口喷出物一致。在不同深度观察到的许多凹形和弧形结构与埋藏的陨石坑和破碎的岩石一致，表明目前在冯卡门埋藏最深30 m的古代月球表面以及当前表面遭受了多次撞击事件. 成像的地下厚古风化层推断冯卡门火山口内火山活动低的静止期。在静止期（剖面图较浅）之后，推测冯卡门火山口出现了一个相对年轻的火山活动期。绘制的这些事件的地层和年代学显示了 SPA 内冯卡门陨石坑的自洽历史，这表明与月球附近事件的联系。