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.
The Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) is a radio frequency subsurface radar sounder designed to operate on the international Mars Express mission, an ESA program for the orbital and in-situ study of the subsurface, surface, ionosphere and atmosphere of the planet Mars. The Mars Express Orbiter spacecraft is developed operated and fully funded by ESA with the exception of the seven payload scientific instruments which will be used for remote observation of the red planet. According to the current ASI/NASA agreement the MARSIS instrument has an Italian PI, an U.S. Co-PI, and Co-I's from the Italy, the U.S. and other countries. There is also an U.S. Experiment Manager and an Italian Deputy Experiment Manager.
The spacecraft of Cassini Mission will be launched towards Saturn in 1997 in order to study the physical structure and chemical composition of Saturn as well as all its moons. To this end many instruments will be mounted on the spacecraft; one of these is the Cassini Radar. Cassini Radar is a cooperative project between National Aeronautics and Space Administration (NASA/Jet Propulsion Laboratory (JPL) and Italian Space Agency (ASI). ASI has committed to Alenia Spazio the design, integration and test of the radio frequency subsystem, while the digital subsystem is the responsibility of JPL. Cassini Radar is a multimode instrument able to operate in an imaging mode (0.85 and 0.425 MHz bandwidth), a scatterometer mode (0.106 MHz bandwidth), and a radiometer mode (100 MHz bandwidth). These modes will be used to acquire images, topographic profile, backscatter reflection coefficient, and sense brightness temperatures of the surface of Titan. Main test results are reported and discussed to demonstrate that the instrument satisfies the mission requirements.