基于MISR数据反演渤海湾气溶胶光学厚度

利用Terra卫星的MISR传感器数据进行渤海湾上空气溶胶反演的初步研究。采用分区暗像元的方法进行反演，传统暗像元大气校正算法认为研究区域上空的气溶胶光学厚度呈均匀分布状态。针对传统暗像元算法的不合理性, 将渤海湾划分为7个子区域, 每个子区域利用传统暗像元算法估算其气溶胶光学厚度, 然后结合空间插值算法获取整个渤海湾的气溶胶光学厚度信息。研究结果表明: 渤海湾上空的气溶胶光学厚度呈沿海岸线高，近海区低的阶梯分布模式，与传统暗像元算法相比, 分区暗像元算法综合考虑了水体上空气溶胶光学厚度空间分布的不均匀性, 有利于改善大气校正的精度。

Back analysis of aerosol optical thickness on Bohai Gulf based on MISR data

Based on the remote sensing data from multi-angle imaging spectroradiometer (MISR),the aerosol optical thickness was calculated. The traditional dark-pixel atmospheric-correction algorithms considered that the aerosol optical thickness had homogeneous distribution above the study region. Taking into account the unreasonable traditional approach, Bohai Gulf was divided into 7 sub-regions. Using the traditional dark-pixel algorithm, the aerosol optical thickness of each sub-region was estimated. Then, space interpolation approach was adopted to calculate the aerosol optical thickness of the whole Bohai Gulf. The results show that, the aerosol optical thickness is lower on offshore area and higher on coastal zone. Comparing with the traditional dark-pixel algorithm, the nonuniform distribution of aerosol optical thickness in space is fully considered by the sub-region dark algorithm, which is beneficial to improve the accuracy of atmospheric correction.