A Volumetric P-band Imaging Concept for the SAR Exploration of Saturn’s Moon Enceladus

In the frame of the Enceladus Explorer Initiative (EnEx) conducted at the German Aerospace Center (DLR), we are currently investigating the potential of an orbital Synthetic Aperture Radar (SAR) instrument to contribute in the understanding of the surface and subsurface structure and composition of the Enceladean ice crust and the involved geophysical processes. The proximity of Saturn constrains the stable solutions for an Enceladus SAR orbiter. The resulting orbit geometries offer the possibility to exploit extremely wide angular observations, with typical integration times of about 800 s to 6000 s, which can be used for a single-pass volumetric imaging approach to provide 3-D metric resolution imagery of the ice crust. The approach is based on the sensitivity of the SAR surveys to the permittivity profiles of the ice. Additionally, we explore the potential of multi-pass acquisitions to provide both accurate imaging and permittivity estimation.