太湖地区气溶胶光学厚度的分布及其在大气校正中的应用

Distribution of aerosol optical depth in Taihu Lake and its application of atmospheric correction

采用太湖地区水面光谱数据以及MODIS遥感影像数据,利用辐射传输模式6S,选择自定义气溶胶类型,反演得到太湖地区气溶胶光学厚度(aerosol optical depth,AOD)分布,将其与太阳光度计CE318实测气溶胶光学厚度分别应用于太湖区域的大气校正中,得到不同的水面反射率,并参考实测水面反射率进行对比分析。结果表明:反演的太湖地区气溶胶光学厚度分布较为合理,造成此分布的原因可能是太湖北岸工业较发达,污染较严重。太湖颗粒物的吸收特性和卫星接收到的表观反射率导致反演数据的差异,是反演气溶胶光学厚度分布不均匀的主要原因。使用MODIS数据反演得到的太湖地区AOD进行大气校正,更加精确。该研究方法和结果可为气溶胶光学厚度反演、精确卫星数据大气校正提供参考。

Based on the water surface spectral data in Taihu Lake area and MODIS remote sensing image data on the same day, this paper retrieved the aerosol optical depth （AOD） in Taihu Lake area by using the radiative transfer model 6S and selecting the user-defined aerosol model. The retrieved AOD data and the AOD data measured by CE318 were applied to the atmospheric correction in Taihu Lake area, respectively, so the two different water reflectivities were gotten and compared with the measured water reflectivity. Results show that the distribution of retrieved AOD in Taihu Lake area is reasonable, which is mainly caused by the developed industry and the more serious pollution in the north of Taihu Lake. The differences of retrieved data induced by the spectral absorption coefficients of particulate and the apparent reflectivity received by the satellite lead to the nonuniform distribution of retrieved AOD. It is more accurate by using the AOD retrieved by MODIS data to do the atmospheric correction. The method and results will be helpful for the retrieval of AOD and the accuracy of atmospheric correction.