Description
The VIIRS/NPP Nadir BRDF-Adjusted Reflectance Daily L3 Global 500 m SIN Grid NRT (VNP43IA4N) product provides NBAR estimates at 500 meter (m) resolution. The VNP43IA4N product is produced daily using 16-day VIIRS data (i.e., the current day and the previous 15 days). The view angle effects are removed from the directional reflectances resulting in a stable and consistent Bidirectional Reflectance Distribution Function (BRDF) Adjusted Reflectance (NBAR) product.
The VNP43 algorithm uses the RossThick/Li-Sparse-Reciprocal (RTLSR) semi-empirical kernel-driven BRDF model, with the three kernel weights from VNP43IA1N to reconstruct surface anisotropic effects, correcting the directional reflectance to a common view geometry (VNP43IA4N), while also computing integrated black-sky albedo (BSA) at local solar noon and white-sky albedo (WSA) (VNP43IA3N). 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) at https://lpdaac.usgs.gov/sites/default/files/public/product_documentation/vnp43_v1_atbd.pdf.
The VNP43IA4N product includes six SDS layers for BRDF/Albedo mandatory quality and nadir reflectance for VIIRS imagery bands I1, I2, and I3.
Product Summary
Citation
Citation is critically important for dataset documentation and discovery. This dataset is openly shared, without restriction, in accordance with the EOSDIS Data Use and Citation Guidance.
Copy Citation
Data Center Citation
Documents
GENERAL DOCUMENTATION | NASA LANCE Near Real Time Data Product Information |