VIIRS/NPP BRDF/Albedo Quality Daily L3 Global 500m SIN Grid V001

The VNP43IA2 Version 1 data product was decommissioned on July 31, 2025. Users are encouraged to use the [VNP43IA2](https://doi.org/10.5067/VIIRS/VNP43IA2.002) and [VJ143IA2](https://doi.org/10.5067/VIIRS/VJ143IA2.002) Version 2 data products. The NASA/NOAA Suomi National Polar-orbiting Partnership (Suomi NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) Bidirectional Reflectance Distribution Function (BRDF) and Albedo Quality (VNP43IA2) Version 1 product provides BRDF and Albedo quality at 500 meter (m) resolution. The VNP43IA2 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 VNP43IA2 product provides information regarding band quality and days of valid observation within a 16-day period for the VIIRS imagery bands. 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 [VNP43IA1](https://doi.org/10.5067/VIIRS/VNP43IA2.001) to reconstruct surface anisotropic effects, correcting the directional reflectance to a common view geometry ([VNP43IA4](https://doi.org/10.5067/VIIRS/VNP43IA4.001)), while also computing integrated black-sky albedo (BSA) at local solar noon and white-sky albedo (WSA) ([VNP43IA3](https://doi.org/10.5067/VIIRS/VNP43IA3.001)). 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 VNP43IA2 data product provides a total of 11 SDS layers including: BRDF/Albedo band quality (inversion information) and days of valid observation within a 16-day period for VIIRS imagery bands I1, I2, and I3, as well as land water type class flag, snow BRDF albedo class flag, local solar noon, albedo uncertainty and the platform name. Known Issues * The abnormally high activation of the high aerosol flag in the Collection 1 (C1) VNP09 product has impacted downstream products. The VNP43 BRDF/Albedo/NBAR product is affected by reducing the number of otherwise acceptable observations used as input to characterize surface anisotropy. This effect (most obvious over arid bright surfaces) results in a reduced number of high quality full BRDF model inversions. Therefore, users should be aware that bright arid surfaces (normally associated with high quality BRDF/Albedo/NBAR retrievals) are likely to be somewhat represented by lower quality results in C1. VNP09 has been corrected for Collection 2 (C2). Therefore, users should avoid substantive use of C1 VNP43 over arid regions (and wait for C2 products). In any event, users are always strongly encouraged to download and use the extensive QA data provided in VNP43[I-M]A2, in addition to the briefer mandatory QA provided as part of the VNP43[I-M]A1, 3 and 4 products. * For complete information about known issues please refer to the [MODIS/VIIRS Land Quality Assessment website](https://landweb.modaps.eosdis.nasa.gov/knownissue?sensor=VIIRS).

Tags: earth-science-surface-radiative-properties-land-surface-albedo, earth-science-surface-radiative-properties-land-surface-anisotropy, earth-science-surface-radiative-properties-land-surface-reflectance
Organization: National Aeronautics and Space Administration