VIIRS/NPP Surface Reflectance Daily L3 Global 0.05 Deg CMG NRT

TheVNP09CMG_NRT is a Near Real Time (NRT) daily surface reflectance Climate Modeling Grid Version 2 product which provides an estimate of land surface reflectance from the NASA/NOAA Suomi National Polar-orbiting Partnership (Suomi NPP) VIIRS sensor. Data are provided for three imagery bands (I1-I3) and nine moderate resolution bands (M1-M5, M7, M8, M10, M11) at 0.05 degree (~5,600 meter) resolution. The data are corrected for atmospheric conditions such as the effects of molecular gases, including ozone and water vapor, and for the effects of atmospheric aerosols. This product uses a weighted average of the best quality observation and is formatted as a CMG for use in climate simulation models. This product includes the twelve reflectance bands, five moderate resolution brightness temperature bands (M12-M16) and information layers representing relative azimuth angle, sensor zenith angle, solar zenith angle, reflectance band quality, time of day, and number mapping.

Surface reflectance is obtained by adjusting top-of-atmosphere reflectance to compensate for atmospheric effects. Corrections are made for the effects of molecular gases, including ozone and water vapor, and for the effects of atmospheric aerosols. The inputs to the surface reflectance algorithm include top-of-atmosphere reflectance for the VIIRS visible bands (VNP02MOD, VNP02IMG), the VIIRS cloud mask and aerosol product (NPP-CMIP_L2), aerosol optical thickness (NPP_VAOTIP_L2, NPP_VAMIP_L2), and atmospheric data obtained from a reanalysis (surface pressure, atmospheric precipitable water, and ozone concentration).

All surface reflectance products are produced for daytime conditions only. The product is produced under all atmospheric conditions except for night and oceans. Pixels when not produced are replaced by fill values in the Level-2 and Level-2G products.

For more information read Suomi-NPP VIIRS Surface Reflectance User's Guide at https://viirsland.gsfc.nasa.gov/PDF/VIIRS_Surf_Refl_UserGuide_v2.0.pdf

or

visit VIIRS Land website at https://viirsland.gsfc.nasa.gov/Products/NASA/ReflectanceESDR.html

TheVNP09CMG_NRT 为近实时（NRT）每日地表反射率气候模拟网格第2版产品，该产品基于美国国家航空航天局/国家海洋和大气管理局（NASA/NOAA）苏奥米国家极轨伙伴计划（Suomi NPP）的VIIRS传感器，提供了对地表反射率的估算。数据涵盖三个图像波段（I1-I3）和九个中等分辨率波段（M1-M5, M7, M8, M10, M11），分辨率为0.05度（约5,600米）。数据已对大气条件进行校正，包括分子气体（如臭氧和水蒸气）的影响，以及大气气溶胶的影响。该产品采用加权平均法，以最佳质量观测值为基础，并格式化为CMG，以便在气候模拟模型中使用。此产品包括十二个反射率波段、五个中等分辨率亮度温度波段（M12-M16）以及代表相对方位角、传感器天顶角、太阳天顶角、反射率波段质量、一天中的时间和映射数量的信息层。

地表反射率通过调整大气顶反射率以补偿大气效应而获得。对分子气体（包括臭氧和水蒸气）的影响以及大气气溶胶的影响进行了校正。地表反射率算法的输入包括VIIRS可见波段（VNP02MOD, VNP02IMG）的大气顶反射率、VIIRS云掩膜和气溶胶产品（NPP-CMIP_L2）、气溶胶光学厚度（NPP_VAOTIP_L2, NPP_VAMIP_L2）以及从再分析中获得的大气数据（地表气压、大气可降水量和臭氧浓度）。

所有地表反射率产品仅针对白天条件生产。产品在除夜间和海洋之外的所有大气条件下生产。未生产的像素在Level-2和Level-2G产品中由填充值替换。

欲了解更多信息，请参阅苏奥米-NPP VIIRS地表反射率用户指南：https://viirsland.gsfc.nasa.gov/PDF/VIIRS_Surf_Refl_UserGuide_v2.0.pdf

或访问VIIRS陆地网站：https://viirsland.gsfc.nasa.gov/Products/NASA/ReflectanceESDR.html