FlyRadar – targets for future drone based GPR survey on Mars

The possibility and feasibility of future drone-based shallow subsurface GPR radar survey for Mars have been examined. SHARAD data indicates shallower features are expected to be present, while HiRISE based analysis of outcrops confirm there are several target features, waiting for radar identification. Targets for an airborne shallow subsurface radar were evaluated including ice content of indurated dunes, internal layering of fluvial deposits, mid- and high latitude ice containing features, former crater lake sediments and lava caves; as well as expected dielectric constant values. The proposed instrument will be able to explore discontinuities in the underground to measure thickness, volume and stratigraphic sequence. Airborne GPR is expected to provide such information what is not achievable by rovers with limited traverse capability and inability of crossing several terrain types. The radar penetration will be increased compared to those characteristics on the Earth by the low humidity expected in the Martian subsurface, while the iron-oxides could decrease the signal with scattering effect and the normal attenuation due to imaginary part of dielectric constant. As radar signals are strongly affected by the presence of liquid water that is very common of Earth, the FlyRadar instrument will be tested mostly in dry areas that are arid hot deserts, karsts or cold arid areas where water is frozen. The suggested trade off according to the geology of the investigated areas was found for the survey of the top 50 m of subsurface could be done at 20 MHz of bandwidth with 80 MHz of transmitted frequency. The mass of such an instrument could reach kilogram payload. The drone technology is available to do survey at 10 km scale distances, what neither an orbiter nor a surface rover could achieve, in order to support next missions for science and ISRU activities.