The research activities performed in the radar laboratory of the DIET Dept., Sapienza University of Rome, are mainly related to the use of radar systems for remote sensing applications, with particular attention to the observation of planetary bodies of the Solar System.
Presently most of the activities involve the processing and the analysis of data acquired by the three radars designed at the Department under the leadership of professors Giovanni Picardi and Roberto Seu: the Cassini radar, the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) and the SHAllow RADar (SHARAD).
The Ku-band Cassini radar is part of the payload of the joint NASA/ESA/ASI Cassini mission. Researchers at the Radar Laboratory are responsible for the processing of data acquired in altimetry mode during the mission’s fly-bys over the surface of Titan, which is the most important moon of Saturn and one of the most intriguing bodies of the solar system. The joint analysis of data acquired in SAR and altimetry modes made possible the discovery of several seas, lakes and rivers on the surface of Titan. An extensive analysis revealed that they are composed mainly of liquid hydrocarbons like methane and ethane. For the first time, the bathymetry of some basins was also carried out. The joint collaboration involves both researchers of the Cornell University, Ithacaa, NY, USA, with scientists of the NASA/JPL and of several European research institutes.
The MARSIS and SHARAD radar sounders are currently on board the ESA Mars Express mission and the NASA Mars Reconnaissance Orbiter mission, respectively. The two sounders share a primary scientific objective: the search for the presence of water, possibly in liquid form, below the subsurface of Mars. System specifications are complementary, allowing the study of both the shallow and the deep subsurface of the planet up to a depth of a few kilometers.
Researchers at Radar Laboratory oriented their efforts to data analysis by developing both processing algorithms and simulators aiming at solving the inversion problem, which leads to the estimation of the dielectric characteristics of the subsurface layers detected by the radars. Although to date no liquid water was found, wide CO2 ice deposits were discovered, which led to significant achievements in the understanding of the climatological and geological evolution of the planet Mars. Significant achievements were also reached in the study of the martian ionosphere.
Considering the level of excellence reached in both system development and data processing, our group was invited to join an international team for the feasibility study (system design, signal processing and performance analysis) of innovative radar systems as payload for candidate future missions. These collaborations include the JPL proposals for an interferometric SAR for a future mission to Venus (VERITAS) and the radar sounder Clipper for the exploration of Jupiter’s moon Europa.