Geological mapping of Titan by multiple observations analysis

SPAGNUOLO, M.G.; F. GRINGS; CARBALLO, F.

La Plata

Taller; IX Taller de Ciencias Planetarias; 2018

Titan is the largest moon of Saturn and second in size of the Solar System. It possesses a dense atmosphere and a great variety of geological features on its surface. In this work we analyzed five areas of Titan around Belet region using multiple observations with the Cassini RADAR instrument for each area at different dates (flybys). Data acquired with different geometries (incidence and azimuth angles) allows to constrain the interpretation of the surface model, since the results must adjust to the different variables of the observations.The study area analyzed is located at the edge of Belet region, between 6.5$^{circ}$-10$^{circ}$ south latitude, and 288$^{circ}$ - 293$^{circ}$ west longitudes. The area is characterized by an alternation of ?bright? (high backscattering) and ?dark? (low backscattering) linear features, enclosed by bright terrains, with an orientation between 85º and 105º respect to the North.Using radar images, we first perform a geomorphological map, based on the different recognized radar textures (responses) and contact relationships. Then, assuming no significant changes in the terrain structure and composition between each flyby, we characterized each geomorphological unit by the mean backscattering between the different images. This methodology was repeated in each of the five areas, generating a database that was used to perform an automatic supervised classification. Acquiring data in this way, makes possible to estimate a surface roughness compatible with the observations, and evaluate if this roughness is compatible with constraints derived from other evidences (e.g. other Cassini sensors, general geomorphological analysis, and hypothesis about Titan?s dunes composition, mechanical properties and formation). Thereby, a geomorphological map of Belet areas was made, recognizing different units based not only in terrain interpretation but also in backscattering data from multiple observation geometries, generating a database for automatic mapping.