SHARAD P/L (SHAllow RADar PayLoad) is a subsurface sounding radar provided by the Italian Space Agency (ASI) as a facility instrument for the NASA mission to Mars called MRO (Mars Recoinnassance Orbiter).
The objective of the SHARAD is to detect the liquid water and to profile the ice layers within the first few hundreds of meters of the subsurface of Mars. Even if Mars surface is not uniformly apt for radar sounding, it will however be possible to find favourable conditions which may allow the identification from orbit of aqueous layers.
SHARAD will also provide new scientific data about Martian soil, ground morphologies and overall geology.
To summarize, the primary objective of the SHARAD investigation is to map, in selected sites, dielectric interfaces to depths of up to one kilometer in the Martian subsurface and to interpret these interfaces in terms of the occurrence and distribution of expected materials, including rock, regolith, water, and ice.
Key elements for the radar design are represented by the identified center frequency, 20 MHz, the bandwidth of the radar pulse equal to 10 MHz, and the requested spatial resolution which should be better than 1000 m in the along track direction and 7000 m in the cross track direction.
In the paper SHARAD design, its technological implications and tradeoffs are presented. In addition the architectural scheme of the instrument is described and an overview of the expected performances is given.