基于Ⅱ类水体短波红外(Short-Wave Infrared,SWIR)波段离水反射率为0的假设,提出一种反演Ⅱ类水体上空气溶胶参数的算法(CaseⅡWater Algorithm,C2W),并与AERONET(Aerosol Robotic Network)太湖站实测数据进行了比较分析.结果表明,反演得到的0.670μm与0.870μm两个波段的气溶胶光学厚度(Aerosol Optical Depth,AOD)与实测值呈现明显的线性关系(R2=0.974、0.971),在气溶胶光学厚度τ〉0.2时不确定性在Δτ=±0.03±0.05τ范围内.11期气溶胶有效半径(Aerosol Effective Radius,AER)数据中,9期的不确定性在±25%范围内,另外两期数据的不确定性在±30%以内.反演精度符合MODIS气溶胶产品的精度要求.
A retrieval algorithm on aerosol properties using MODIS datasets over caseⅡwaters(C2W)in Taihu Lake was proposed by assuming zero water-leaving reflectance at short-wave infrared(SWIR)bands,and was validated using aerosol datasets from the Taihu station of the Aerosol Robotic Network(AERONET).The aerosol optical depth(AOD)retrieved at 0.670 μm and 0.870 μm fell within an uncertainty of Δτ=±0.03±0.05τ(τ〉0.2),showing significant linearity with the AERONET datasets(R2=0.974、0.971).As far as the accuracy and precision of the aerosol effective radius(AER)are concerned,9 of the 11 AER retrieved using the C2W algorithm fell within a uncertainty of ±25%,while the other 2 fell within ±30%,which meets the requirements of the MODIS aerosol products.