Research on The Surface Reflectance Model in Satellite Measurement Scale

在这项研究中，我们利用Terra MODIS图像和地面测量的气溶胶光学厚度（AOT）确定了日本陆地地区可见光和红外波段之间的地表反射率。使用新确定的反射率比，我们在卫星检索和地面检索的AOT之间获得了令人满意的一致性。对于土地BRDF模型，我们使用法国POSTEL， Medias France的POLDER-1衍生的BRDF数据库，分析了之前提出的经验BRDF模型，如Li_sparse-Ross_thick模型和Li_sparse-Ross_thick with Hot Spot模型。这些模型由三个核分量组成，即各向同性核分量、几何核分量和体积散射核分量。通过选择适当的系数，我们确认它们能够拟合大多数目标类别的测量BRDF值。由于我们发现阴影函数是一个非常好的体散射核分量的候选，它应该更倾向于使用，而不是经验分量，因为我们可以在理论上推导阴影函数，基于辐射传递理论。我们提出了li -稀疏阴影BRDF陆地目标模型，并成功地对各种实测BRDF目标进行了测试。对于海面BRDF，我们基于对太阳闪烁POLDER图像的分析，提出了Cox-Munk模型中风速和海面坡度的新参数。

In this study, we determined the surface reflectance ratios between visible and infrared bands for land areas in Japan, using Terra MODIS images and the ground-measured aerosol optical thickness(AOT). We obtained a satisfactory agreement between the satellite-retrieved and ground-retrieved AOT, using the newly determined reflectance ratios.As for the BRDF models for lands, we analyzed the previously proposed empirical BRDF models, such as the Li_sparse-Ross_thick model and Li_sparse-Ross_thick with Hot Spot model, using the BRDF Database derived from POLDER-1 by POSTEL, Medias France. These models consist of three kernet components, namely, an isotropic, a geometric and a volume scattering kernel components. We confirmed they are able to fit the measured BRDF values for most target categories, by choosing appropriate coefficients. Since we found the shadowing function is a very good candidate for a volume scattering kernel component, it should prefer to use, instead of empirical component, because we can derive the shadowing function theoretically, based on the radiative transfer theory. We proposed the Li-sparse-shadowing BRDF model for land target and the proposed model was tested successfully for various measured BRDF targets.As for the sea surface BRDF, we proposed new parameters for the wind speed and surface slope in the Cox-Munk model, based on the analysis of the sun glitter POLDER images.