Titan's ground reflectance retrieval from Cassini-VIMS data taken during the July 2nd, 2004 fly-by at 2 AM UT

An attempt to evaluate the preliminary values of the Titan's surface albedo at 2 ìm from the first Cassini-VIMS observations of the moon is presented. The methodology is based on the application of radiative transfer calculations and a microphysical model of the Titan atmosphere based on fractal aerosol. As a first guess, the surface has been considered flat and lambertian. The results are presented as a function of the geographical coordinates associated to the image pixels. The libRadtran package, using the radiative transfer equation solver DISORT 2.0, has been applied for the calculations. A test run to evaluate the model performances, using ground based observations of Titan as reference in the range of wavelengths 0.3-1.0 ìm, has been carried out.The retrieved values of the surface albedo range between 0.03 and 0.22.