Mini-SAR: an imaging radar experiment for the Chandrayaan-1 mission to the Moon

Abstract

Mini-SAR is a single frequency (S-band; 13-cm wavelength) Synthetic Aperture Radar (SAR) in a lightweight (~9 kg) package. Previous Earth- and space-based radar observations of the permanently shadowed regions of the lunar poles have measured areas of high circular polarization ratio consistent with volume scattering from water ice buried at shallow (0.1‐1 m) depths. This detection is not definitive because of poor viewing geometry and a limited number of observations. Mini-SAR utilizes a unique hybrid polarization architecture, which allows determination of the Stokes parameters of the reflected signal, intended to distinguish volume scattering (caused by the presence of ice) from other scattering mechanisms (e.g. sub-wavelength scale surface roughness).