Physical-based scattering model for Titan: Integrating Cassini microwave data (active and passive)

GRINGS, F.; FRANCO, M.; SPAGNUOLO, M.G.; JANSSEN, M.A.; LORENZ, R.

ICARUS

ACADEMIC PRESS INC ELSEVIER SCIENCE

Año: 2021 vol. 359

0019-1035

Cassini´s microwave data can be used to constrain the physical properties of Titan´s surface, i.e., its composition, surface roughness and sub-surface structure. Physically-based models characterized by these properties can simulate the microwave signal emanating from such a surface due to both the reflection of an incident RADAR signal and its intrinsic thermal emission. Having multiple active and passive observations of a given region better allows us to determine such physical properties. In this work we selected an area of Titan between Belet and Senkyo and analyzed all the available microwave data (backscattering observations corresponding to three flybys and the emissivity map from the concurrent radiometric data) to find physical parameters consistent with these data. In particular we propose a two-layered structure for the surface, which, in combination with a small-perturbation approach, we found could successfully be used to estimate physical properties from observational data. Our results show that the backscattering and emissivity values of all the geomorphic units identified in our study can be explained using the proposed model.