VNP43DNBA3 v001

VIIRS/NPP DNB Albedo Daily L3 Global 1 km SIN Grid


PI: Crystal Schaaf

Description

The Suomi National Polar-Orbiting Partnership (S-NPP) NASA Visible Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) Bidirectional Reflectance Distribution Function (BRDF) and Albedo (VNP43DNBA3) Version 1 product provides albedo values at 1 kilometer (km) resolution for the bihemispherical reflectance white-sky albedos (WSA) and directional hemispherical reflectance black-sky albedos (BSA) at local solar noon. The VNP43DNBA3 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 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 VNP43DNBA3 product provides BSA, WSA, and mandatory quality layers for the VIIRS DNB. A low-resolution image is also available showing retrievals of WSA for the shortwave broadband in JPEG format.

read more

Characteristics

Product Maturity

Validation at stage 1 has been achieved for the VIIRS BRDF/Albedo product suite. Visit the VIIRS Land Product Quality Assessment website for additional information on validation and product maturity status.

Collection and Granule

Collection

Characteristic Description
CollectionS-NPP VIIRS
DOI10.5067/VIIRS/VNP43DNBA3.001
File Size~7.25 MB
Temporal ResolutionDaily
Temporal Extent2012-01-19 to Present
Spatial ExtentGlobal
Coordinate SystemSinusoidal
DatumN/A
File FormatHDF-EOS5
Geographic Dimensions1200 km x 1200 km

Granule

Characteristic Description
Number of Science Dataset (SDS) Layers3
Columns/Rows1200 x 1200
Pixel Size1000 m

Layers

SDS Name Description Units Data Type Fill Value No Data Value Valid Range Scale Factor
Albedo_BSA_DNB BSA (at local solar noon) for DNB N/A 16-bit signed integer 37267 N/A 0 to 1000 0.001
Albedo_WSA_DNB WSA for DNB N/A 16-bit signed integer 37267 N/A 0 to 1000 0.001
BRDF_Albedo_Band_Mandatory_Quality_DNB BRDF/Albedo mandatory quality band for DNB N/A 8-bit unsigned integer 255 N/A 0 to 1 N/A

Product Quality

Product accuracy/uncertainty information can be found in section 4 of the ATBD. Additional quality information can be found in the VNP43DNBA2 data product.

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.

Additional known issues for VNP43 data products can be found on the VIIRS Land Quality Assessment website.

Documentation

Using the Data

Access Data

Citation

DOI: 10.5067/VIIRS/VNP43DNBA3.001

About the Image

The Albedo BSA day/night band from the VNP43DNBA3 product over Algeria, Africa on October 1, 2019.

View full-size image