Spectral Content of Solar Radiation on Martian Surface Based on Mars Pathfinder

Abstract

Photovoltaicarrayswereused successfully to power thevarious instrumentsfortheMars Pathe nder.To identify the type of the solar cell most suitable for Mars surface missions in the future, the spectral content of Mars’ s solar radiation must e rst be determined. The response of photovoltaic cells depends on the solar cell type and the wavelengths of the incident light. The suspended dust particles of Mars’ s atmosphere affect the intensity and spectralcontent of the solarradiation reaching theplanet’ s surface. ThePathe nderemployed fourbandpasse lters formeasuring theatmosphericoptical depth during the courseof themission that lasted for about80 sols (Martian days). Thecentral wavelengths of thesee lterswere 450, 670, 883, and 989 nm. This paper deals with theanalysis of theopticaldepthoftheMartian atmospherebased ontheMarsPathe ndermeasurementsand includes1 ) variation of the monochromatic optical depth with the time of the day, 2 ) variation of the monochromatic optical depth with sol for the duration of the mission, 3 ) variation of the optical depth with wavelength, 4 ) transmittance of the direct beam with wavelength, and 5 ) solar cell response on the Martian surface of the direct beam irradiance.