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Description

The NASA/NOAA Suomi National Polar-orbiting Partnership (Suomi NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) Nadir Bidirectional Reflectance Distribution Function (BRDF) Adjusted Reflectance (NBAR) Version 2 product provides NBAR estimates at 1 kilometer (km) resolution. The VNP43IA4 product is produced daily using 16-day VIIRS data and is weighted temporally to the 9th day, which is reflected in the file name. The view angle effects are removed from the directional reflectances resulting in a stable and consistent NBAR product.

The VNP43 data products are designed after the Moderate Resolution Imaging Spectroradiometer (MODIS) BRDF/Albedo product suite to promote the continuity of the Earth Observation System (EOS) mission. 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 VNP43MA1 to reconstruct surface anisotropic effects, correcting the directional reflectance to a common view geometry (VNP43MA4), while also computing integrated black-sky albedo (BSA) at local solar noon and white-sky albedo (WSA) (VNP43MA3). 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 VNP43MA4 product includes 18 SDS layers for BRDF/Albedo mandatory quality and nadir reflectance for VIIRS nine moderate bands M1-M5, M7-M8, and M10-M11. A low-resolution browse image is also available showing NBAR bands M5, M7, and M5 as an RGB image in JPEG format.

Known Issues

Improvements/Changes from Previous Versions

  • Improved calibration algorithm and coefficients for entire Suomi NPP mission.
  • Improved geolocation accuracy and applied updates to fix outliers around maneuver periods.
  • Corrected 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 VNP13 Vegetation Indices and VNP43 Bidirectional Reflectance Distribution Function (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 the eight-class land/water mask from the VNP03 geolocation product that better aligns with MODIS.
  • More details can be found in this VIIRS Land V2 Changes document.

Version Description

Collection Version 2 Processing and Reprocessing

Product Summary

Platforms
Suomi-NPP
Instruments
VIIRS
Spatial Extent
N: 90 S: -90 E: 180 W: -180
Spatial Resolution
1000 Meters x 1000 Meters
Geographic Region
GLOBAL
Coordinate System
CARTESIAN
Granule Spatial Representation
GEODETIC
Temporal Extent
2012-01-17 to Present
Temporal Resolution
1 Day
Data Partner
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)
Land Processes Distributed Active Archive Center (LP DAAC)
School for the Environment, University of Massachusetts, Boston (UMASS-B/SFE)
Concept ID
C2545314608-LPCLOUD
Data State
ACTIVE
Processing Level
3
Published
Updated
Science Keywords
Reflectance,
Anisotropy,
Albedo

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/NPP BRDF/Albedo Nadir BRDF-Adjusted Ref Daily L3 Global 1km SIN Grid V002 [Data set]. NASA Land Processes Distributed Active Archive Center. https://doi.org/10.5067/VIIRS/VNP43MA4.002 Date Accessed: 2025-11-02

File Naming Convention

VNP43MA4.A2025222.h01v11.002.2025230232527.h5

The file name begins with the Product Short Name (VNP43MA4) followed by the Julian Date of Acquisition formatted as AYYYYDDD (A2025222), the Tile Identifier which is horizontal tile and vertical tile provided as hXXvYY (h01v11), the Version of the data collection (002), the Julian Date and Time of Production designated as YYYYDDDHHMMSS (2025230232527), and the Data Format (h5).

Documents

USER'S GUIDE

ALGORITHM THEORETICAL BASIS DOCUMENT (ATBD)

PRODUCT QUALITY ASSESSMENT

SCIENCE DATA PRODUCT VALIDATION

GENERAL DOCUMENTATION

Variables

Variables are a set of physical properties whose values determine the characteristics or behavior of something. For example, temperature and pressure are variables of the atmosphere. Parameters and variables can be used interchangeably. Variable level attributes provide individual information for each variable.

The Name in this table is the variable name. Fill value indicates missing or undefined data points in a variable. Valid range is the range of values the variable can store. Scale factor is used to increase or decrease the size of an object and can be used to correct for distortion. 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_M1 BRDF/Albedo mandatory quality for band M1 Class Flag uint8 255 255 to 1 N/A
BRDF_Albedo_Band_Mandatory_Quality_M2 BRDF/Albedo mandatory quality for band M2 Class Flag uint8 255 255 to 1 N/A
BRDF_Albedo_Band_Mandatory_Quality_M3 BRDF/Albedo mandatory quality for band M3 Class Flag uint8 255 255 to 1 N/A
BRDF_Albedo_Band_Mandatory_Quality_M4 BRDF/Albedo mandatory quality for band M4 Class Flag uint8 255 255 to 1 N/A
BRDF_Albedo_Band_Mandatory_Quality_M5 BRDF/Albedo mandatory quality for band M5 Class Flag uint8 255 255 to 1 N/A
BRDF_Albedo_Band_Mandatory_Quality_M7 BRDF/Albedo mandatory quality for band M7 Class Flag uint8 255 255 to 1 N/A
BRDF_Albedo_Band_Mandatory_Quality_M8 BRDF/Albedo mandatory quality for band M8 Class Flag uint8 255 255 to 1 N/A
BRDF_Albedo_Band_Mandatory_Quality_M10 BRDF/Albedo mandatory quality for band M10 Class Flag uint8 255 255 to 1 N/A
BRDF_Albedo_Band_Mandatory_Quality_M11 BRDF/Albedo mandatory quality for band M11 Class Flag uint8 255 255 to 1 N/A
Nadir_Reflectance_M1 Nadir BRDF/Albedo reflectance at local solar noon for band M1 N/A int16 32767 32767 to 10000 0.0001
Nadir_Reflectance_M2 Nadir BRDF/Albedo reflectance at local solar noon for band M2 N/A int16 32767 32767 to 10000 0.0001
Nadir_Reflectance_M3 Nadir BRDF/Albedo reflectance at local solar noon for band M3 N/A int16 32767 32767 to 10000 0.0001
Nadir_Reflectance_M4 Nadir BRDF/Albedo reflectance at local solar noon for band M4 N/A int16 32767 32767 to 10000 0.0001
Nadir_Reflectance_M5 Nadir BRDF/Albedo reflectance at local solar noon for band M5 N/A int16 32767 32767 to 10000 0.0001
Nadir_Reflectance_M7 Nadir BRDF/Albedo reflectance at local solar noon for band M7 N/A int16 32767 32767 to 10000 0.0001
Nadir_Reflectance_M8 Nadir BRDF/Albedo reflectance at local solar noon for band M8 N/A int16 32767 32767 to 10000 0.0001
Nadir_Reflectance_M10 Nadir BRDF/Albedo reflectance at local solar noon for band M10 N/A int16 32767 32767 to 10000 0.0001
Nadir_Reflectance_M11 Nadir BRDF/Albedo reflectance at local solar noon for band M11 N/A int16 32767 32767 to 10000 0.0001
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