X - 2 Bernard - Michel Et Al . : Retrieval of Mars Surface Physical Properties

In this paper, a statistical method is proposed to evaluate the 4 physical properties of surface materials on Mars from hyperspectral images 5 collected by the OMEGA instrument aboard the Mars express spacecraft. 6 The approach is based on the estimation of the functional relationship F be-7 tween some observed spectra and some physical parameters. To this end, a 8 database of synthetic spectra is generated by a physical radiative transfer 9 model and used to estimate F. The high dimension of spectra is reduced by 10 Gaussian regularized sliced inverse regression (GRSIR) to overcome the curse 11 of dimensionality and consequently the sensitivity of the inversion to noise 12 (ill-conditioned problems). Compared with other approaches, GRSIR has the 13 advantage of being very fast, interpretable and accurate.