MODIS/Terra Surface Reflectance 8-Day L3 Global 500m SIN Grid V061

The Moderate Resolution Imaging Spectroradiometer (MODIS) Terra MOD09A1 Version 6.1 product provides an estimate of the surface spectral reflectance of Terra MODIS Bands 1 through 7 corrected for atmospheric conditions such as gasses, aerosols, and Rayleigh scattering. Along with the seven 500 meter (m) reflectance bands are two quality layers and four observation bands. For each pixel, a value is selected from all the acquisitions within the 8-day composite period. The criteria for the pixel choice include cloud and solar zenith. When several acquisitions meet the criteria the pixel with the minimum channel 3 (blue) value is used. Known Issues搭载于Terra卫星的中分辨率成像光谱仪（Moderate Resolution Imaging Spectroradiometer，MODIS）所生成的MOD09A1 6.1版产品，可提供经大气条件（包括气体、气溶胶与瑞利散射）校正后的Terra MODIS第1至7波段地表光谱反射率估算值。该产品包含7个500米分辨率的反射率波段，同时附带2个质量图层与4个观测波段。针对每个像元，将从8天合成周期内的所有观测数据中选取一个取值。像元选取的判定标准包括云量与太阳天顶角；若有多个观测数据符合标准，则选取3波段（蓝光波段）取值最小的像元。已知问题