Multilayer simulations for accurate geological interpretations of SHARAD radargrams

M.G. SPAGNOULO; F.GRINGS; P.PERNA; M.FRANCO; H. KARSZENBAUM; V.A.RAMOS

PLANETARY AND SPACE SCIENCE

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Noordwijk, Netherlands; Año: 2010 p. 1 - 9

0032-0633

SHARAD (SHAllowRADar) is a nadir-looking SyntheticAperture Ground Penetrating RadaronboardNASA’s 2005 Mars Reconnaissance Orbiter. There are three main characteristics that define theperformanceof this instrument: ground penetration(due to the operational frequency, the observed echoes can be related to reflections from surface or sub surface), spaceborne operation (the first reflection does not necessarily correspond to then a dirreflection), and nadir looking SAR (there will always be left / right ambiguities). All this implies that there will be surface / sub surface range ambiguity and the geological interpretation of the radargrams cannot be straightforward. In order to avoid data mis-interpretation, a simulator of SHARAD’s expected response for a given observation geometry and topography is needed. Simulations can take into account all surface / subsurface reflections in order to identify common families of ambiguities and facilitate the interpretation. In this work we present SHARSIM (SHARAD Radargram SIMulator), a software tool designed to simulate SHARAD radargrams taking as inputs Mars surface information and hypothetical subsurface structure. Its performance is analyzed by investigating typical artifacts and by a direct comparison with real radargrams. We show thatSHARSIM simulations can help to discern between artifacts and real subsurface features in order to make accurate geological interpretations.