| Autor: |
Giannakis, Iraklis, Zhou, Feng, Warren, Craig, Giannopoulos, Antonios |
| Předmět: |
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| Zdroj: |
Geophysical Research Letters; 8/28/2021, Vol. 48 Issue 16, p1-14, 14p |
| Abstrakt: |
The current paper investigates the shallow layers of the lunar regolith at the Chang'E‐4 landing site. Four layers between 0 and 10 m were identified using lunar penetrating radar. Based on these outputs, a revised stratigraphic model is suggested for the post‐Imbrian ejecta at the Von Kármán 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. Plain Language Summary: The landing site of Chang'E‐4 is at the Von Kármán (VK) crater at the South Pole‐Aitken (SPA) basin. The SPA basin is the oldest and biggest basin on the Moon created at the early stages of its evolution by an impact that is, believed to have penetrated the lunar crust and uplifted materials from the top mantle. Understanding the geology and stratigraphy of the SPA basin can help us understand cratering processes and shed light on the evolution of the Moon. To that extent, ground penetrating radar (GPR) has been added to the payload of Yutu‐2 to investigate the stratigraphy of the Chang'E‐4 landing site. One drawback of GPR is that conventional processing methods fail to detect layers with smooth boundaries between them. Consequently, GPR data might give the false impression that an area is relatively homogenous, while in fact it might consist of numerous gradational layers representing a much more complex geological history. In the current paper, a novel interpretation tool is described, capable of detecting smooth transitions between layers. The proposed methodology revealed a previously unseen layered structure for the first ∼10 m of the VK crater. Key Points: We suggest a novel hyperbola‐fitting technique that assumes an arbitrary permittivity distribution with respect to depthThe proposed method is used to map the lunar regolith at the Chang'E‐4 landing siteA layered structure is revealed at the first 10 meters. A new stratigraphic model is suggested for the Von Kármán crater [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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