Abstract
Error budget analysis and sensitivity analysis of the method for aerosol refractive index and size distribution estimation with ground based polarization measurement data for vicarious calibration of solar reflection channels of mission instruments onboard satellites are performed. The proposed method uses a relation between aerosol refractive index and p and s polarized downwelling solar diffuse irradiance. It is much easy to measure p and s polarized irradiance on the ground with a portable measuring instrument rather than solar direct, diffuse and aureole measurements. Through theoretical and simulation studies, it is found that the proposed method shows an acceptable estimation accuracy of refractive index and size distribution using measured downwelling p and s polarized irradiance data with a measuring instrument. It found that Degree of Polarization : DP is most sensitive to imaginary part refractive index followed by real part of refractive index, aerosol optical depth, surface reflectance and Junge parameter. It is also found that 5% of error of DP measurement is acceptable for less than 3% of estimation accuracy of aerosol refractive index and size distribution. The instrument is pointing to the several directions from the center of perpendicular to the sun in the principal plane. Field experimental results also show a validity of the proposed method in comparison to the estimated results from the conventional method with solar direct, diffuse and aureole measurement data.
