Subsurface imaging method (SSIM) based on phase compensation of radar echoes

In this paper we describe an inversion approach to analyze the data of radar sounders like MARSIS (Mars Advance Radar for Subsurface and Ionosphere Sounding) on board Mars Express and SHARAD (Mars Shallow Radar Sounder) aboard the Mars Reconnaissance Orbiter. Radar echoes from flat terrain with stratified subsurface structures can be described by the reflection coefficient of each interface. The reflection coefficient is calculated by the inversion method introduced in this paper. Using a phase compensation of the radar echo, the strong reflections in the subsurface structure can be localized. This allows us to differentiate consecutive subsurface layers in high resolution. The reflection coefficients are calculated interface echo by interface echo. Composing the reflection coefficients of all interfaces we reconstruct the Mars subsurface. In a recursive process, starting with the known dielectric constant of free space, the dielectric properties of the subsurface layer´s are calculated layer by layer. Multiple reflections are taken into account. One example of a dielectric profile shown in this paper indicates a stratified Mars subsurface structure.