N: 90 S: -90 E: 180 W: -180
Description
The NOAA-20 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 VJ143MA4 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 VJ143 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 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 VJ143MA1 to reconstruct surface anisotropic effects, correcting the directional reflectance to a common view geometry (VJ143MA4), while also computing integrated black-sky albedo (BSA) at local solar noon and white-sky albedo (WSA) (VJ143MA3). 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 VJ143MA4 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
- For complete information about known issues please refer to the MODIS/VIIRS Land Quality Assessment website.
Version Description
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.
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File Naming Convention
The file name begins with the Product Short Name (VJ143MA4) 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
USER'S GUIDE
ALGORITHM THEORETICAL BASIS DOCUMENT (ATBD)
PRODUCT QUALITY ASSESSMENT
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 Sort descending | 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 | 0 to 1 | N/A |
| BRDF_Albedo_Band_Mandatory_Quality_M2 | BRDF/Albedo mandatory quality for band M2 | Class Flag | uint8 | 255 | 0 to 1 | N/A |
| BRDF_Albedo_Band_Mandatory_Quality_M3 | BRDF/Albedo mandatory quality for band M3 | Class Flag | uint8 | 255 | 0 to 1 | N/A |
| BRDF_Albedo_Band_Mandatory_Quality_M4 | BRDF/Albedo mandatory quality for band M4 | Class Flag | uint8 | 255 | 0 to 1 | N/A |
| BRDF_Albedo_Band_Mandatory_Quality_M5 | BRDF/Albedo mandatory quality for band M5 | Class Flag | uint8 | 255 | 0 to 1 | N/A |
| BRDF_Albedo_Band_Mandatory_Quality_M7 | BRDF/Albedo mandatory quality for band M7 | Class Flag | uint8 | 255 | 0 to 1 | N/A |
| BRDF_Albedo_Band_Mandatory_Quality_M8 | BRDF/Albedo mandatory quality for band M8 | Class Flag | uint8 | 255 | 0 to 1 | N/A |
| BRDF_Albedo_Band_Mandatory_Quality_M10 | BRDF/Albedo mandatory quality for band M10 | Class Flag | uint8 | 255 | 0 to 1 | N/A |
| BRDF_Albedo_Band_Mandatory_Quality_M11 | BRDF/Albedo mandatory quality for band M11 | Class Flag | uint8 | 255 | 0 to 1 | N/A |
| Nadir_Reflectance_M1 | Nadir BRDF/Albedo reflectance at local solar noon for band M1 | N/A | int16 | 32767 | 0 to 10000 | 0.0001 |
| Nadir_Reflectance_M2 | Nadir BRDF/Albedo reflectance at local solar noon for band M2 | N/A | int16 | 32767 | 0 to 10000 | 0.0001 |
| Nadir_Reflectance_M3 | Nadir BRDF/Albedo reflectance at local solar noon for band M3 | N/A | int16 | 32767 | 0 to 10000 | 0.0001 |
| Nadir_Reflectance_M4 | Nadir BRDF/Albedo reflectance at local solar noon for band M4 | N/A | int16 | 32767 | 0 to 10000 | 0.0001 |
| Nadir_Reflectance_M5 | Nadir BRDF/Albedo reflectance at local solar noon for band M5 | N/A | int16 | 32767 | 0 to 10000 | 0.0001 |
| Nadir_Reflectance_M7 | Nadir BRDF/Albedo reflectance at local solar noon for band M7 | N/A | int16 | 32767 | 0 to 10000 | 0.0001 |
| Nadir_Reflectance_M8 | Nadir BRDF/Albedo reflectance at local solar noon for band M8 | N/A | int16 | 32767 | 0 to 10000 | 0.0001 |
| Nadir_Reflectance_M10 | Nadir BRDF/Albedo reflectance at local solar noon for band M10 | N/A | int16 | 32767 | 0 to 10000 | 0.0001 |
| Nadir_Reflectance_M11 | Nadir BRDF/Albedo reflectance at local solar noon for band M11 | N/A | int16 | 32767 | 0 to 10000 | 0.0001 |