Martian roughness analogues of Europan terrains for radar sounder investigations

Abstract

Understanding the implications of Europa's roughness on backscattered radar signals is central to ensure that the future radar sounding instruments heading for the Jovian icy moons, the Radar for Icy Moons Exploration (RIME) and the Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON), will yield fruitful observations over their Europan targets. In this paper we analyse the roughness of Mars in terms of piecewise monofractal behaviour, and compare the derived Allan profiles to those of different types of Europan terrains. Using the MOLA dataset, we created roughness analogue maps for 12 different types of Europan terrains, and performed additional analysis with High Resolution Imaging Science Experiment (HiRISE) DTM data to complement our study. We found that Aeolis Planum, the flanks of Tharsis Montes, and the chaos terrain south of Olympus Mons are particularly rich in Europan roughness analogues. To put our findings into context, we present optical image comparisons between some Europan terrains and a given Martian roughness analogue, as well as SHARAD and MARSIS tracks passing over some of these areas of interest.