VIIRS/NPP Nadir BRDF-Adjusted Reflectance Daily L3 Global 500m SIN Grid NRT
The VIIRS/NPP Nadir BRDF-Adjusted Reflectance Daily L3 Global 500 m SIN Grid Near Real Time (NRT), short-name 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://www.umb.edu/editor_uploads/images/school_for_the_environment_cs/Viirs/VIIRS_ATBD_Apr_Jul2017.pdf.The VNP43IA4N product includes six SDS layers for BRDF/Albedo mandatory quality and nadir reflectance for VIIRS imagery bands I1, I2, and I3.
Complete Metadata
| @type | dcat:Dataset |
|---|---|
| accessLevel | public |
| bureauCode |
[
"026:00"
]
|
| contactPoint |
{
"fn": "Earthdata Forum",
"@type": "vcard:Contact",
"hasEmail": "mailto:earthdata-support@nasa.gov"
}
|
| description | The VIIRS/NPP Nadir BRDF-Adjusted Reflectance Daily L3 Global 500 m SIN Grid Near Real Time (NRT), short-name 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://www.umb.edu/editor_uploads/images/school_for_the_environment_cs/Viirs/VIIRS_ATBD_Apr_Jul2017.pdf.The VNP43IA4N product includes six SDS layers for BRDF/Albedo mandatory quality and nadir reflectance for VIIRS imagery bands I1, I2, and I3. |
| distribution |
[
{
"@type": "dcat:Distribution",
"title": "Data Information (Unknown Format)",
"format": "BIN",
"mediaType": "application/octet-stream",
"downloadURL": "https://earthdata.nasa.gov/earth-observation-data/near-real-time/download-nrt-data/viirs-nrt"
},
{
"@type": "dcat:Distribution",
"title": "Data Information (Unknown Format)",
"format": "BIN",
"mediaType": "application/octet-stream",
"downloadURL": "https://nrt4.modaps.eosdis.nasa.gov/archive/allData/5200/VNP43IA4N/"
}
]
|
| identifier | 10.5067/VIIRS/VNP43IA4N.002 |
| keyword |
[
"earth-science-surface-radiative-properties-land-surface-albedo",
"earth-science-surface-radiative-properties-land-surface-anisotropy"
]
|
| landingPage | https://nrt4.modaps.eosdis.nasa.gov/archive/allData/5200/VNP43IA4N/ |
| modified | 2026-02-17 |
| programCode |
[
"026:000"
]
|
| publisher |
{
"name": "NASA/GSFC/SED/ESD/TISL/MODAPS",
"@type": "org:Organization"
}
|
| spatial |
"["CARTESIAN",[{"NorthBoundingCoordinate":80,"WestBoundingCoordinate":-180,"EastBoundingCoordinate":180,"SouthBoundingCoordinate":-80}]]"
|
| temporal | 2023-11-20/2023-11-20 |
| theme |
[
"Earth Science"
]
|
| title | VIIRS/NPP Nadir BRDF-Adjusted Reflectance Daily L3 Global 500m SIN Grid NRT |
