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Description

The NOAA-20 Visible Infrared Imaging Radiometer Suite (VIIRS) Bidirectional Reflectance Distribution Function (BRDF) and Albedo Model Parameters (VJ143IA1) Version 2 product provides kernel weights (parameters) at 500 meter (m) resolution. The VJ143IA1 product is produced daily using 16 days of VIIRS data, temporally weighted to the ninth day, which is reflected in the file name. The VJ143IA1 product provides three spectrally dependent kernel weights, also known as model parameters: isotropic (fiso), volumetric (fvol), and geometric (fgeo), which can be used to model anisotropic effects of the Earth’s surface. All VJ143 data products are designed to promote the continuity of NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) BRDF/Albedo data product suite.

The VJ143 algorithm uses the RossThick/Li-Sparse-Reciprocal (RTLSR) semi-empirical kernel-driven BRDF model, with the three kernel weights from VJ143IA1 to reconstruct surface anisotropic effects, correcting the directional reflectance to a common view geometry (VJ143IA4), while also computing integrated black-sky albedo (BSA) at local solar noon and white-sky albedo (WSA) (VJ143IA3). 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 VNP43IA1 data product provides a total of six SDS layers including: three mandatory quality layers for bands I1, I2, and I3 and three multi-dimensional model parameter bands representing fiso, fvol, and fgeo for each imagery band. Each data product file is provided in HDF-EOS5 format. A low-resolution browse is also available showing BRDF/Albedo parameters for VIIRS imagery bands: I1, I2, and I1 as an RGB (red, green, blue) image in JPEG format.

Known Issues

Version Description

NOAA-20 (JPSS-1) VIIRS data products, designated as "VJ1", were introduced in VIIRS Version 2.

Product Summary

Platforms
NOAA-20
Instruments
VIIRS
Spatial Extent

N: 90 S: -90 E: 180 W: -180

Spatial Resolution
500 Meters x 500 Meters
Spatial Reference System(s)
VIIRS Sinusoidal Tiling System
Location
GLOBAL
Coordinate System
CARTESIAN
Granule Spatial Representation
GEODETIC
Temporal Extent
2018-01-01 to Present
Temporal Resolution
1 Day
Data Partner
Land Processes Distributed Active Archive Center (LP DAAC) ,
School for the Environment, University of Massachusetts, Boston (UMASS-B/SFE) ,
Land Science Investigator-led Processing System, Terrestrial Information Systems Laboratory, Earth Sciences Division, Sciences and Exploration Directorate, Goddard Space Flight Center, NASA (NASA/GSFC/SED/ESD/TISL/LandSIPS)
Concept ID
C2545310914-LPCLOUD
Data State
ACTIVE
Number of Files/Granules
950940
Processing Level
3
Published
Updated
Science Keywords
Reflectance ,
Albedo ,
Anisotropy

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

Schaaf, C., Wang, Z., Erb, A., & Paynter, I. (2024). VIIRS/JPSS1 BRDF/Albedo Model Parameters Daily L3 Global 500m SIN Grid V002 [Data set]. NASA Land Processes Distributed Active Archive Center. https://doi.org/10.5067/VIIRS/VJ143IA1.002 Date Accessed: 2026-02-13

File Naming Convention

VJ143IA1.A2025215.h03v05.002.2025223072110.h5

The file name begins with the Product Short Name (VJ143IA1) followed by the Julian Date of Acquisition formatted as AYYYYDDD (A2025215), the Tile Identifier which is horizontal tile and vertical tile provided as hXXvYY (h03v05), the Version of the data collection (002), the Julian Date and Time of Production designated as YYYYDDDHHMMSS (2025223072110), and the Data Format (h5).

Documents

Variables

The table below lists the variables contained within a single granule for this dataset. Variables often contain observed or derived geophysical measurements collected from a variety of sources, including remote sensing instruments on satellite and airborne platforms, field campaigns, in situ measurements, and model outputs. The terms variable, parameter, scientific data set, layer, and band have been used across NASA’s Earth science disciplines; however, variable is the designated nomenclature in NASA’s Common Metadata Repository (CMR). Variable metadata attributes such as Name, Description, Units, Data Type, Fill Value, Valid Range, and Scale Factor allow users to efficiently process and analyze the data. The full range of attributes may not be applicable to all variables. Additional information on variable attributes is typically available in the data, user guide, and/or other product documentation.

For questions on a specific variable, please use the Earthdata Forum.

Name Description Units Data Type Fill Value Valid Range Scale Factor
BRDF_Albedo_Band_Mandatory_Quality_I1 BRDF/Albedo mandatory quality for band I1 Class Flag uint8 255 0 to 1 N/A
BRDF_Albedo_Band_Mandatory_Quality_I2 BRDF/Albedo mandatory quality for band I2 Class Flag uint8 255 0 to 1 N/A
BRDF_Albedo_Band_Mandatory_Quality_I3 BRDF/Albedo mandatory quality for band I3 Class Flag uint8 255 0 to 1 N/A
BRDF_Albedo_Parameters_I1 Multi-dimensional layer for band I1 of parameters: fiso, fvol, and fgeo N/A int16 32767 0 to 32766 0.001
BRDF_Albedo_Parameters_I2 Multi-dimensional layer for band I2 of parameters: fiso, fvol, and fgeo N/A int16 32767 0 to 32766 0.001
BRDF_Albedo_Parameters_I3 Multi-dimensional layer for band I3 of parameters: fiso, fvol, and fgeo N/A int16 32767 0 to 32766 0.001
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