陆上气溶胶光学厚度（AOD）反演作为气候、环境领域的一大研究方向，偏振多角度遥感在这个方向上有其特有的优势。本文使用法国POLDER （Polarization and Directionality of Earth’s Reflectance） 1级偏振多角度资料，提出了一种针对气溶胶反演的群组残差最优方法，反演了气溶胶AOD。首先，模拟计算了大气、地表和气溶胶的偏振多角度反射率；然后，通过辐射传输公式，推算卫星观测的偏振表观反射率的若干组模拟值；最后，使用群组残差最优方法，计算获得气溶胶AOD。通过和MODIS（Moderate-resolution Imaging Spectroradiometer）气溶胶数据产品（MYD04）的精确地理匹配和定量分析，验证了此方法的反演精度，结果表明：本文得到的AOD与MYD04建立的回归分析，其R²可达到0.68以上，斜率与1接近，即此方法获得的反演产品与MYD04具有较好的一致性；与AERONET（Aerosol Robotic Network）的AOD数据也进行了坎普尔站、北京站上的统计与分析，AOD的变化趋势上也存在较好的一致性。本文方法能够应用于除POLDER以外的偏振多角度卫星数据，获得较为可靠的陆上气溶胶AOD产品。

Aerosol is one of the important components of the earth’s atmospheric environment, which has a profound impact on atmospheric transport, climate simulation, environmental research, remote sensing application, pollution monitoring and many other fields. The retrieval of the Aerosol Optical Depth (AOD) over land has always been an important research topic in the study of environment and climate. As an emerging remote sensing method in recent years, multi-angular polarized remote sensing has obvious advantages over traditional optical remote sensing in the problem of land-atmosphere decoupling, which has been rapidly applied and developed in the field of cloud and aerosol. In this study, an Optimal Grouped Residual Method for the aerosol was proposed, which uses the multi-angular polarized data of POLDER Level 1 datasets (Polarization and Directionality of Earth’s Reflectance, France). According to Mie scattering theory, the polarization scattering phase function of atmospheric aerosol were calculated. Then, the polarization reflectance contribution of aerosols was calculated based on the polarization scattering phase function of aerosols, and the polarization reflectance contribution of atmospheric gas molecules and the surface were calculated using empirical formula. Finally, the multi-angular apparent polarization reflectance of the top of the atmosphere under the assumption of single scattering was simulated according to the atmospheric radiative transfer theory, and AOD was retrieved.The retrieval results and accuracy were verified by precisely geographic matching and quantitatively comparing with MODIS (Moderate-resolution Imaging Spectroradiometer) aerosol product (MYD04). The results show that the R-square values of the regression analysis between AOD in this study and MYD04 can reach more than 0.68, and the slopes are close to 1, which reveal a good consistency. The AOD results were also compared with AERONET (Aerosol Robotic Network) in two sites, Beijing and Kanpur, revealing that the variation trends of AOD have good consistency. Furthermore, in order to verify the reliability of the method in this study from a broader spatial-temporal dimension, the AOD results were synthesized on a long time series of multi-day. Similarly, the multi-day synthetic AOD results obtained in this study also showed good consistency with the MODIS results. This method can be applied to multi-angular polarized satellite data (not only POLDER) to generate reliable optical depth products for the aerosol over land.