Inversion of Mars' Zephyria Planum Based on Roughness Correction

The Zephyria Planum on Mars is a vast plain, and long-term wind erosion has shaped the surface of the westerly plain and its surrounding plains. SHARAD data shows that certain areas within the area have obvious underground structures. Quantitative inversion was conducted using SHARAD data and electromagnetic wave propagation principles to determine the attenuation constant and dielectric constant of Zephyria Planum underground. The first inversion result shows that the attenuation constant of the first layer is about 1.4e-03, and the subsurface dielectric constant is 7. Traditional inversion methods, such as the preliminary method used in this study, are based on the assumption that the surface layer and the sub-surface layer have the same roughness. However, this assumption may overlook the significant impact of roughness on the accuracy of dielectric constant inversion. To achieve more accurate inversion, this paper introduces a roughness correction method. We selected data with a pulse width of -3dB less than 0.15e-6s for precise inversion. After this roughness correction, the underground dielectric constant we obtained is 6.5, and the attenuation constant is 9.1e-4, which is consistent with the geological structure of the area mainly composed of water ice and rock. In addition, we also found that the porosity of the study area is approximately 70%.