Titan’s Surface at 2.2-Cm Wavelength: Results and Interpretations through the First Ten Years of Observation By Cassini
Résumé
A comprehensive calibration and mapping of the thermal microwave emission from Titan’s surface will be presented, based on radiometric data obtained at 2.2-cm wavelength by the passive radiometer in the Cassini Radar instrument through the nearly ten years following Saturn Orbit Insertion. The data reported were accumulated from Titan passes Ta (October 2004) through T98 (February 2014) and now incorporate emission from all of Titan’s surface. The mapping will eventually include data at both low and high spatial resolution, while for the present we concentrate on only the low-resolution data that provide thermal polarization. These data are sufficient to examine not only surface effective dielectric constant but seasonal and diurnal surface temperature variations, which we compare with current CIRS results. The map of effective dielectric constant allows us to explore possible regional variations in surface properties and composition. Finally, these data allow us to understand the nature and magnitude of systematic errors in the map-making process, essential to interpreting both the present maps and the forthcoming high-resolution maps based on these. This work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.