Ground-Penetrating Radar Modeling across the Jezero Crater Floor

Abstract

This article assesses how the ground-penetrating radar RIMFAX will image the crater floor at the Mars 2020 landing site, where lithological compositions and stratigraphic relationships are under discussion prior to mission operation. A putative mafic unit (lava flow, volcanic ash, or volcaniclastic deposit) on the crater floor will be crucial in piecing together the chronology of deposition and for understanding the volcanic history in the region. In order to see how lithological properties and subsurface geometries affect radar sounding, a synthetic radargram is generated through forward modeling with a finite-difference time-domain method. The acquisition is simulated across the mafic unit as a succession of lava flows, exploring detection of internal structures and contacts to adjacent lithologies. To compare modeling results with the alternative formation scenarios, a discussion about sounding over a tephra or volcaniclastic material is presented. Similarities and differences between Martian and terrestrial lithologies can be related to electromagnetic properties relevant for radar sounding. This article, therefore, evaluates potential scientific insights gained from acquisition across the disputed mafic unit, in light of proposed hypotheses of lithological generation.