Spectral information retrieval from integrated broadband photodiode UV measurements

Abstract

We propose an algorithm to retrieve the global features of the spectral dependence of the ultraviolet (UV) irradiance from integrated, broadband UV measurements performed with a set of photodiodes with different UV filters. This fit, when applied to ground based measurements and compared to the incident Solar spectral irradiance on the top of the atmosphere, may be used to extract the spectral dependence of the UV opacity and the most relevant parameters characterizing the scattering with atmospheric aerosol (Angstrom exponent, etc) as well as the biological effective doses. In this way, using a set of photodiodes instead of a spectrophotometer, one may get spectral information within very low mass, package and weight constraints, which is particular useful for space missions. We consider its application for the rover-based exploration of the Martian ground which is subjected to daily and seasonal opacity variations.