Radar Sounding of Planetary Bodies: An Instrument Design Approach

A number of cornerstone missions have been planned by ESA and NASA for the observation of planetary bodies. Radar Altimeters are always considered as baseline instruments to be carried on the spacecrafts, given their suitability of retrieving informations about not only surface topography but also, due to the microwave capability of penetrating the media (especially if dry as it is the case for planetary bodies), about subsurface layering and topography (sounding). Such kind of informations, other than scientifically relevant, are also very important when the landing of the spacecraft on the body is to be considered, being an useful tool for inferring the safety of the selected landing site.