VNP43MA4 v001

VIIRS/NPP Nadir BRDF-Adjusted Reflectance 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) Nadir Bidirectional Reflectance Distribution Function (BRDF) Adjusted Reflectance (NBAR) Version 1 product provides NBAR estimates at 1 kilometer (km) resolution. The VNP43IA4 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 view angle effects are removed from the directional reflectances resulting in a stable and consistent NBAR product. 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 (red, green, blue) image in JPEG format.

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/VNP43MA4.001
File Size~100 MB
Temporal ResolutionDaily
Temporal Extent2012-01-19 to Present
Spatial ExtentGlobal
Coordinate SystemSinusoidal
DatumN/A
File FormatHDF-EOS
Geographic Dimensions1200 km x 1200 km

Granule

Characteristic Description
Number of Science Dataset (SDS) Layers18
Columns/Rows1200 x 1200
Pixel Size1000 m

Layers

SDS Name Description Units Data Type Fill Value No Data Value Valid Range Scale Factor Additional Offset
BRDF_Albedo_Band_Mandatory_Quality_M1 BRDF/Albedo mandatory quality for band M1 N/A 8-bit unsigned integer 255 N/A 0 to 1 N/A N/A
BRDF_Albedo_Band_Mandatory_Quality_M10 BRDF/Albedo mandatory quality for band M10 N/A 8-bit unsigned integer 255 N/A 0 to 1 N/A N/A
BRDF_Albedo_Band_Mandatory_Quality_M11 BRDF/Albedo mandatory quality for band M11 N/A 8-bit unsigned integer 255 N/A 0 to 1 N/A N/A
BRDF_Albedo_Band_Mandatory_Quality_M2 BRDF/Albedo mandatory quality for band M2 N/A 8-bit unsigned integer 255 N/A 0 to 1 N/A N/A
BRDF_Albedo_Band_Mandatory_Quality_M3 BRDF/Albedo mandatory quality for band M3 N/A 8-bit unsigned integer 255 N/A 0 to 1 N/A N/A
BRDF_Albedo_Band_Mandatory_Quality_M4 BRDF/Albedo mandatory quality for band M4 N/A 8-bit unsigned integer 255 N/A 0 to 1 N/A N/A
BRDF_Albedo_Band_Mandatory_Quality_M5 BRDF/Albedo mandatory quality for band M5 N/A 8-bit unsigned integer 255 N/A 0 to 1 N/A N/A
BRDF_Albedo_Band_Mandatory_Quality_M7 BRDF/Albedo mandatory quality for band M7 N/A 8-bit unsigned integer 255 N/A 0 to 1 N/A N/A
BRDF_Albedo_Band_Mandatory_Quality_M8 BRDF/Albedo mandatory quality for band M8 N/A 8-bit unsigned integer 255 N/A 0 to 1 N/A N/A
Nadir_Reflectance_M1 Nadir BRDF/Albedo reflectance at local solar noon for band M1 N/A 16-bit signed integer 32767 N/A 0 to 10000 0.0001 N/A
Nadir_Reflectance_M10 Nadir BRDF/Albedo reflectance at local solar noon for band M10 N/A 16-bit signed integer 32767 N/A 0 to 10000 0.0001 N/A
Nadir_Reflectance_M11 Nadir BRDF/Albedo reflectance at local solar noon for band M11 N/A 16-bit signed integer 32767 N/A 0 to 10000 0.0001 N/A
Nadir_Reflectance_M2 Nadir BRDF/Albedo reflectance at local solar noon for band M2 N/A 16-bit signed integer 32767 N/A 0 to 10000 0.0001 N/A
Nadir_Reflectance_M3 Nadir BRDF/Albedo reflectance at local solar noon for band M3 N/A 16-bit signed integer 32767 N/A 0 to 10000 0.0001 N/A
Nadir_Reflectance_M4 Nadir BRDF/Albedo reflectance at local solar noon for band M4 N/A 16-bit signed integer 32767 N/A 0 to 10000 0.0001 N/A
Nadir_Reflectance_M5 Nadir BRDF/Albedo reflectance at local solar noon for band M5 N/A 16-bit signed integer 32767 N/A 0 to 10000 0.0001 N/A
Nadir_Reflectance_M7 Nadir BRDF/Albedo reflectance at local solar noon for band M7 N/A 16-bit signed integer 32767 N/A 0 to 10000 0.0001 N/A
Nadir_Reflectance_M8 Nadir BRDF/Albedo reflectance at local solar noon for band M8 N/A 16-bit signed integer 32767 N/A 0 to 10000 0.0001 N/A

Product Quality

Product Quality information can be found in the ATBD in Table 10 on page 24. Product accuracy/uncertainty information can be found in section 4 on pages 20-22. Additional quality information can be found in the VNP43MA2 data product.

Known Issues

There are no known issues.

Documentation

Using the Data

Tools

Citation

DOI: 10.5067/VIIRS/VNP43MA4.001

About the Image