ShaRad data in the area of Oxia Planum paving the way for WISDOM radar on the ExoMars2022 rover

In June 2023, the ExoMars mission rover will land in Oxia Planum to search for traces of life in the Martian subsurface [1]. To reach this objective, the rover is equipped with a drill able to collect samples down to two meters in the subsurface and with a suite of complementary instruments. Among these instruments, the Ground Penetrating Radar WISDOM has been designed to study the structure of the first meters of the Martian subsurface and thus provide key information on the geological context of the landing site, and also to detect the potential hazards that might jeopardize the drilling operations [2]. WISDOM is operating over a broad frequency Bandwidth (from 0.5 to 3 GHz) that allows to reach a vertical resolution of few centimeters (commensurate with the samples length) [3]. Operating at much lower frequencies, the sounding radar SHARAD on board the NASA's Mars Reconnaissance Orbiter (MRO) has acquired data from orbit, over the area of Oxia Planum. In order to retrieve information about the local variability of the surface roughness and of the electrical permittivity in the very shallow subsurface, we characterize the surface echoes measured by SHARAD in the studied area in terms of echo amplitude and shape, after applying BWE (BandWidth Extrapolation) technique to improve the resolution of the soundings [4], [5]. The observed variability is analyzed in the light of the MOLA topography and of images acquired from orbit to get an as complete as possible understanding of the area [6]. Acknowledgement: SHARAD was provided by NASA and the Italian Space Agency (ASI). [1] Vago et al., Astrobiology, 2017. [2] Ciarletti et al., Astrobiology, 2017. [3] Oudart et al., Planetary and Space Science, 2021. [4] Mastrogiuseppe et al.: AGU publications, 2014. [5] Raguso et al.: IEEE, 2018. [6] Elliot Sefton-Nash et al., EPSC Abstracts 2020