Radar sensing of plains and playas : Titan and Terrestrial Analogs

Prior to Cassini's arrival at Titan, radar observations made with the giant Arecibo radio telescope indicated regions on Titan tens of kilometers across that were flat to a cm level. These specular reflections were... [ view full abstract ]

Prior to Cassini's arrival at Titan, radar observations made with the giant Arecibo radio telescope indicated regions on Titan tens of kilometers across that were flat to a cm level. These specular reflections were interpreted, following Occam's razor, as possible lakes or seas.
In fact, most of these areas appear to be associated with sand dunes : the very flat interdune areas are presumably formed either as lakebeds prior to dune emplacement, or as Stokes surfaces where aeolian sand has been trapped by a shallow groundwater table contemporaneous with dune growth/migration.
In addition to the Arecibo data (at S-band, 13cm), Cassini's radar instrument (Ku-band, 2cm) provides SAR imaging and nadir-pointed altimetry, the latter dataset being particularly sensitive to flat surfaces. Additional data include Cassini bistatic scattering experiments at S- and X- band, and Ku-band information from the altimeter on the Huygens probe. These datasets will be compared with remote sensing and field data from analog terrains on Earth including interdune areas in the Arabian, Australian and Badain Jaran desert, as well as playa, lakebeds and salt flats such as Death Valley, the Afar and the Sahara.