The NOAA-20 Visible Infrared Imaging Radiometer Suite (VIIRS) Bidirectional Reflectance Distribution Function (BRDF) and Albedo Nadir BRDF-Adjusted Reflectance (NBAR) for Band M4 (VJ143D83) 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 VJ143D 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 VJ143D product contains just one data layer. VJ143D80 through VJ143D89 are the NBAR products of the VJ143D 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 VJ143MA4 product. In addition to the bands included in VJ143MA4, 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 VJ143MA4 product page and in the Algorithm Theoretical Basis Document (ATBD). VJ143D83 is the NBAR for VIIRS band M4 (0.555 μm). Known Issues * For complete information about known issues please refer to the MODIS/VIIRS Land Quality Assessment website. Improvements/Changes from Previous Versions The NOAA-20 VIIRS algorithms include the same improvements as the S-NPP VIIRS V002 * Improved calibration algorithm and better coefficients for entire NOAA-20 mission * Improved geolocation accuracy and updates to fix outliers around maneuver periods and other events * Corrections to the aerosol quantity flag (low, average, high) mainly over brighter surfaces in the mid to high latitudes such as desert and tropical vegetation areas. This has an impact on the retrieval of other downstream data products such as VJ113 Vegetation Indices and VJ143 BRDF/Albedo. * Improved cloud mask input product for corrections along coastlines and artifacts from use of coarse resolution climatology data * Replaced the land/water mask input product with MODIS heritage seven class land/water mask