ABSTRACT
Comparisons between the Martian disk spectra and the optical properties of terrestrial analogs have been useful in characterizing the properties of the Martian soil [1-5]. However, these have not yet been accomplished with medium resolution (20 cm−1) infrared Martian disk spectra between 2900 and 5600 cm−1. We approached this problem by obtaining medium resolution (20 cm−1) disk infrared spectra of Mars using the NASA Lear Airborne Observatory, with line modeling to deduce (and eliminate) the contribution to the observed spectrum by Martian and telluric CO2. We then determined the optical complex index of refraction of terrestrial analogs of appropriate acceptable minerals and used the results in a surface scattering theory to represent the average Martian soil. From this model a characteristic particle size was obtained. The reflectivities of samples prepared with particles in this size range were then used to match the observed surface reflectivity.
