Abstract

The current paper investigates the shallow layers of the lunar regolith at the Chang'E-4 landing site. Four layers between 0-10 meters were identified using lunar penetrating radar. Based on these outputs, a revised stratigraphic model is suggested for the post-Imbrian ejecta at the Von Karman crater. The layers were previously unseen due to the smooth boundaries between them. The revised model was inferred using an advanced hyperbola-fitting scheme. Applying conventional hyperbola-fitting to non-homogeneous media results in errors and inaccuracies that are often wrongly assumed to be negligible. We propose a novel hyperbola-fitting scheme that is not constrained to homogeneous media and can be applied subject to any arbitrary one-dimensional permittivity distribution. Via this approach, we can estimate the permittivity profile of an investigated area and detect layered structures that were previously transparent to electromagnetic waves due to the gradational dielectric properties at their interfaces.