基于FY-4A卫星数据反演气溶胶光学厚度及分析应用

风云四号A星（FY-4A）是我国新一代静止气象卫星，多通道扫描成像辐射计（AGRI）是风云四号静止气象卫星的主要载荷之一.为探究FY4A数据用于气溶胶光学厚度（AOD）反演的可行性，基于FY-4A/AGRI数据，利用暗像元算法对2019年2月23~26日及10月27~30日京津冀地区AOD进行反演研究，并与AERONET地基观测AOD数据进行了对比分析.结果表明，基于FY-4A数据及构建响应函数库，通过暗像元方法能较好的反演出京津冀地区气溶胶空间分布；AOD主要的高值区体现在京津冀中南部地区并向周边郊区逐渐降低，在AOD值较大时此特征较为明显；将反演值与同期AERONET地基观测数据对比验证，相关系数达到0.869，均方根误差为0.221，表明AOD反演值与观测值吻合较好，FY-4A卫星数据反演AOD具有一定可行性.

Retrieval of aerosol optical depth based on FY-4A satellite data and its analysis and application

FY-4A is among the new generation of geostationary meteorological satellite in China. Advanced Geostationary Radiation Imager (AGRI) is one of the main sensors boarding on FY-4A. In order to investigate the reliability of the Aerosol Optical Depth (AOD) retrieval using FY-4A measurements, the dark target algorithm was carried out to perform the AOD over Beijing-Tianjin-Hebei region of Feb. 23~26 and Oct. 27~30, 2019. For further study, the inversions were validated with the AERONET ground-network observations. The results are indicated that:Based on the response function library of FY-4A, the dark target algorithm leads to a better understanding of the aerosol spatial distribution over Beijing-Tianjin-Hebei region; The maximum of AOD was mainly in the central and southern part of Beijing-Tianjin-Hebei region, and gradually decreases along the surrounding suburbs; By comparing the retrieval values with the ground-based AERONET observations during the same period, the correlation coefficient was 0.869 and the RMSE was 0.221. It is shown that the AOD retrieval values are in good agreement with the observed values, and the AOD retrieval of FY-4A satellite is reliable.