Retrieval algorithm for atmospheric aerosols based on multi-angle viewing of ADEOS/POLDER

POLDER-sensor onboard the satellite ADEOS has observed the reflected light from Earth surface-atmosphere system at multi-viewing angles. These directional measurements include significant information of scattering particles. The POLDER possesses high radiometric sensitivity and multi-channels in the visible and near infrared wavelengths, and measures polarization as well as radiance. This work intends to show that its multi-spectral and multi-directional measurements are useful to retrieve aerosol characteristics. The basic algorithm for aerosol retrieval is based on light scattering simulations of polarization field, where the heterogeneous aerosol model according to Maxwell-Garnett mixing rule is considered. Monthly global distribution maps showing the Ångström exponent and the optical thickness of aerosols were obtained. From these aerosol maps, it can be seen that the aerosol distribution derived from POLDER radiance and polarization data coincides with that from the radiance data obtained independently from OCTS, and atmospheric aerosols exhibit certain intrinsic feature on a global and on a seasonal scale.