The estimation of aerosol optical parameters from ADEOS/POLDER data

摘要

A cross calibration analysis between POLDER and OCTS sensors on board ADEOS satellite in terms of the space reflectance was made. Space reflectance values, computed from the POLDER and OCTS data (acquired simultaneously on 26 April 1997) for the same ocean target, were examined and we found that they are in good agreement in all bands, when the new in-flight calibration gain factors for each sensor are assumed. Furthermore, we retrieved aerosol optical parameters (i.e., the optical thickness, Ångström exponent, and refractive index) by using several retrieving algorithms from using ADEOS/POLDER’s directional space reflectance and polarization data in infrared bands simultaneously. Retrieved results were presented by the form of distribution maps. In addition, good and bad points of each retrieval algorithm were discussed. Finally, we proposed an improved method for retrieving aerosol optical parameters, which utilizes theoretical P–SR (polarization–space reflectance) diagrams at given viewing angles in an 865 nm band. The estimated aerosol optical parameters by our proposed method were compared with the simultaneously measured sky observation data. We found an excellent agreement between them.