ADEOS搭載POLDERによる反射及び偏光画像データの解析結果

抄録

This paper described the analysis results of the reflectance and polarization image data acquired by POLDER on board ADEOS satellite. The ADEOS/POLDER's reflectance and polarization image data at 0.865, μm over the Arabian Sea near Indian Continent, taken on Nov. 18, 1996, were investigated by using typical aerosol size distribution models, namely, Oceanic, Water-Soluble and Junge models. We made multiple scattering simulations for these models by assuming a tropical atmosphere. A single atmospheric layer model with an isotropic Gaussian type ocean surface (Cox-Munk model) was assumed in this study.
The main results of this study were summarized as follows:
1) We found that Junge model with ν=4.0-4.5 and m =1.50-i[0.00.01] and Water-Soluble model can satisfy the observed reflectance data, as well as the observed polarization data by assuming the typical ocean aerosol optical thickness values.
2) Oceanic aerosol model was rejected on the ground that it failed to explain the observed polarization features.
3) Based on multiple scattering computations, the image construction for both reflectance and linear polarization was made, using the estimated aerosol optical parameters. Simulated images showed that most of characteristic features in the observed images can be theoretically reconstructed.
4) Furthermore, the ocean wind speed at the time of POLDER observation was estimated to be V =4.06.0 m/sec from the analysis of the observed reflectance data.