The NASA/NOAA Suomi National Polar-orbiting Partnership (Suomi NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) Bidirectional Reflectance Distribution Function (BRDF) and Albedo Quality (VNP43DNBA2) Version 2 product provides BRDF and Albedo quality at 1 kilometer (km) resolution. The VNP43DNBA2 product is produced daily using 16 days of VIIRS data and is weighted temporally to the ninth day, which is reflected in the file name. The VNP43DNBA2 product gives information regarding band quality and days of valid observation within a 16-day period for the VIIRS DNB. The VNP43 data products are designed to promote the continuity of NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) BRDF/Albedo data product suite.

The VNP43 algorithm uses the RossThick/Li-Sparse-Reciprocal (RTLSR) semi-empirical kernel-driven BRDF model, with the three kernel weights from VNP43DNBA1 to reconstruct surface anisotropic effects, correcting the directional reflectance to a common view geometry (VNP43DNBA4), while also computing integrated black-sky albedo (BSA) at local solar noon and white-sky albedo (WSA) (VNP43DNBA3). Researchers can use the BRDF model parameters with a simple polynomial to obtain black-sky albedo at any solar illumination angle. Likewise, both the BSA and WSA Science Dataset (SDS) layers can be used with a simple polynomial to manually estimate instantaneous actual albedo (blue-sky albedo). Additional details regarding the methodology are available in the Algorithm Theoretical Basis Document (ATBD).

The VNP43DNBA2 data product provides a total of seven SDS layers, including BRDF/Albedo band quality and days of valid observation within a 16-day period for the VIIRS DNB, as well as land water type class flag, snow BRDF albedo class flag, local solar noon, and the platform name.

Known Issues

• For complete information about known issues please refer to the MODIS/VIIRS Land Quality Assessment website.

Improvements/Changes from Previous Version

• 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