基于GF-4数据的杭州城区大气AOD监测研究

Monitoring of Aerosol Optical Depth in Urban Areas of Hangzhou Based on GF-4 Data

以杭州市8区为研究区,利用高分四号卫星数据,基于暗目标算法和地表反射率数据库相结合的算法,分别对2016年9月2日、2016年9月3日、2016年12月31日和2017年7月26日4个时相的气溶胶光学厚度进行反演,在此基础上分析杭州市AOD的分布特征,并结合MODIS标准陆地气溶胶产品和地基观测数据进行精度验证,同时分析大气污染物与AOD变化之间的关系.结果显示杭州城区气溶胶光学厚度分布特征为东北部高、西南部低;精度验证相关系数分别为0.7和0.9,反演结果相对可靠;研究日内大气颗粒物与气溶胶光学厚度的日内变化趋势基本保持一致,污染物浓度均在中午维持较大水平.

Taking the eight districts of Hangzhou city as the research areas,the gaofen-4 satellite data were used to invert the aerosol optical depth of the four time phases on September 2,2016,September 3,2016,December 31,2016 and July 26,2017,respectively,with the algorithm combining the dark target algorithm and the surface reflectance database.The distribution characteristics of AOD in Hangzhou were analyzed,MODIS standard terrestrial aerosol products and ground-based observation data were used for verification.The relationships between atmospheric pollutants and AOD changes were analyzed.The results showed that the aerosol optical depth distribution in Hangzhou city was high in the northeast and low in the southwest,the correlation coefficients of accuracy verification were 0.7 and 0.9,respectively,and the inversion results were relatively reliable,the intraday variation trend of atmospheric particulate matters and aerosol optical depth was basically consistent,and the pollutant concentration remained at a high level at noon.