The Suomi National Polar-Orbiting Partnership (S-NPP) NASA Visible Infrared Imaging Radiometer Suite (VIIRS) Bidirectional Reflectance Distribution Function (BRDF) and Albedo Nadir BRDF-Adjusted Reflectance (NBAR) for Band M1 (VNP43D80) 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.
VNP43D80 through VNP43D89 are the NBAR products of the VNP43D BRDF/Albedo product suite. NBAR values are provided for the nine VIIRS moderate resolution bands (M1 through M5, M7, M8, M10, and M11) included in the VNP43MA4 product. In addition to the bands included in VNP43MA4, this product suite includes NBAR values for the VIIRS Day/Night Band (DNB). The NBAR algorithm removes view angle effects from directional reflectances to model the values as if they were collected from a nadir view at local solar noon. Details regarding methodology are available on the VNP43MA4 product page and in the Algorithm Theoretical Basis Document (ATBD).
VNP43D80 is the NBAR for VIIRS band M1 (0.412 μm).
|File Size||~220 MB|
|Temporal Extent||2012-01-19 to Present|
|Coordinate System||Geographic Latitude and Longitude|
|Number of Science Dataset (SDS) Layers||1|
|Columns/Rows||43200 x 21600|
|Pixel Size||1000 m|
|SDS Name||Description||Units||Data Type||Fill Value||No Data Value||Valid Range||Scale Factor|
|BRDF_Albedo_NBAR_M1||NBAR for band M1||N/A||16-bit signed integer||32767||N/A||0 to 1000||0.001|
The VIIRS Land Surface Reflectance product (VNP09) flags a larger number of retrievals as ‘High Aerosol’ in the quality layer as compared to the MODIS reflectance product. The inaccurately flagged high aerosol quality flags cause the BRDF retrieval algorithm to incorrectly reject the observations and switch from full inversion (high quality retrieval) to magnitude inversion (low quality retrieval) in the mid to high latitude, arid lands, and tropical vegetative regions.