VIIRS/NPP BRDF/Albedo Valid Observation DNB Daily L3 Global 30ArcSec CMG V002

The NASA/NOAA Suomi National Polar-orbiting Partnership (Suomi NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) Bidirectional Reflectance Distribution Function (BRDF) and Albedo Valid Observation Day/Night Band (DNB) product (VNP43D51) is produced daily using 16 days of data at 30 arc second (1,000 meter) resolution. Data are temporally weighted to the ninth day, which is reflected in the file name. The VNP43D product suite is provided in a Climate Modeling Grid (CMG), which covers the entire globe for use in climate simulation models. Due to the large file size, each VNP43D product contains just one data layer for each of the parameters included in the [VNP43MA2](https://doi.org/10.5067/VIIRS/VNP43MA2.002) product. VNP43D40 through VNP43D53 are the 30 arc second BRDF/Albedo Quality values, the Local Solar Noon values, the Valid Observations of the moderate resolution bands (M1 through M5, M7, M8, M10, and M11) plus the Day/Night Band (DNB), the Snow Status, and the Uncertainty. Details regarding methodology are available on the [VNP43MA2](https://doi.org/10.5067/VIIRS/VNP43MA2.002) product page and in the Algorithm Theoretical Basis Document (ATBD).

VNP43D51 contains the valid observation quality layer representing each of the 16 days of the retrieval period for VIIRS DNB.

Known Issues
* For complete information about known issues please refer to the [MODIS/VIIRS Land Quality Assessment website](https://landweb.modaps.eosdis.nasa.gov/knownissue).

NASA/NOAA 苏奥米国家极轨伙伴卫星（Suomi National Polar-orbiting Partnership, Suomi NPP）搭载的可见光红外成像辐射计套件（Visible Infrared Imaging Radiometer Suite, VIIRS）双向反射分布函数（Bidirectional Reflectance Distribution Function, BRDF）与反照率有效观测昼夜波段（Day/Night Band, DNB）产品（VNP43D51），每日基于16天的观测数据生成，分辨率为30角秒（约1000米）。产品采用时间加权方案，将观测数据加权至反演周期的第9天，该加权信息将体现在产品文件名中。VNP43D系列产品采用气候建模网格（Climate Modeling Grid, CMG）格式，覆盖全球范围，可直接用于气候模拟模型。因单文件体量较大，每个VNP43D产品仅包含[VNP43MA2](https://doi.org/10.5067/VIIRS/VNP43MA2.002)产品中各参数对应的单个数据层。VNP43D40至VNP43D53分别对应30角秒分辨率的BRDF/反照率质量值、当地太阳正午时刻值、中分辨率波段（M1至M5、M7、M8、M10及M11）与昼夜波段（DNB）的有效观测数、积雪状态以及不确定性数据。相关方法学细节可参阅[VNP43MA2](https://doi.org/10.5067/VIIRS/VNP43MA2.002)产品页面及算法理论基础文档（Algorithm Theoretical Basis Document, ATBD）。

VNP43D51包含代表VIIRS DNB反演周期内全部16天观测的有效观测质量图层。

已知问题
* 如需获取完整的已知问题信息，请参阅[MODIS/VIIRS陆地质量评估网站](https://landweb.modaps.eosdis.nasa.gov/knownissue)。