VNP43C3 v001

VIIRS/NPP BRDF/Albedo Albedo Daily L3 Global 0.05 Deg CMG


PI: Crystal Schaaf

Description

The Suomi National Polar-Orbiting Partnership (S-NPP) NASA Visible Infrared Imaging Radiometer Suite (VIIRS) Bidirectional Reflectance Distribution Function (BRDF) and Albedo Albedo Daily Global 0.05 Degree Climate Modeling Grid (CMG) Version 1 product (VNP43C3) is derived from the 30 arc second CMG VNP43D Version 1 product suite. VNP43C3 is generated daily from all available high-quality reflectance data over a 16-day moving window emphasizing the ninth day of the retrieval period, which is reflected in the Julian date in the filename. The VNP43 algorithm uses the RossThick/Li-Sparse-Reciprocal (RTLSR) semi-empirical kernel-driven BRDF model, with the three kernel weights from VNP43C1 to compute white-sky albedos and the black-sky albedos at local solar noon for the VIIRS Day/Night band (DNB), moderate resolution bands M1 through M5, M7, M8, M10, and M11, as well as the shortwave band, visible band, and near-infrared (NIR) broadbands. The quality and inversion status of the majority of the underlying 30 arc second pixels is provided as well as the percentage of the underlying pixels that were present or were snow covered. Users are encouraged to assess the quality information before using the BRDF/Albedo data. This 0.05 degree (5,600 meters at the equator) CMG product covers the entire globe for use in climate simulation models.

The VNP43C3 product includes 26 layers containing white-sky albedos and the black-sky albedos for the VIIRS DNB, moderate resolution bands M1 through M5, M7, M8, M10, and M11, as well as the shortwave band, visible band, and NIR broadbands. Along with the albedo data for the 13 bands are five ancillary layers for uncertainty, quality, local solar noon, percent finer resolution inputs, and snow cover. A low-resolution image is also available showing retrievals of WSA for the shortwave broadband in JPEG format.

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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/VNP43C3.001
File Size~188 MB
Temporal ResolutionDaily
Temporal Extent2012-01-19 to Present
Spatial ExtentGlobal
Coordinate SystemGeographic Latitude and Longitude
DatumN/A
File FormatHDF-EOS5
Geographic DimensionsGlobal

Granule

Characteristic Description
Number of Science Dataset (SDS) Layers31
Columns/Rows7200 x 3600
Pixel Size5600 m

Layers

SDS Name Description Units Data Type Fill Value No Data Value Valid Range Scale Factor
Albedo_BSA_DNB Black-sky albedo for Day/Night band (0.7 μm) N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_BSA_M1 Black-sky albedo for band M1 (0.412 μm) N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_BSA_M10 Black-sky albedo for band M10 (1.61 μm) N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_BSA_M11 Black-sky albedo for band M11 (2.25 μm) N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_BSA_M2 Black-sky albedo for band M2 (0.445 μm) N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_BSA_M3 Black-sky albedo for band M3 (0.488 μm) N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_BSA_M4 Black-sky albedo for band M4 (0.555 μm) N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_BSA_M5 Black-sky albedo for band M5 (0.672 μm) N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_BSA_M7 Black-sky albedo for band M7 (0.865 μm) N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_BSA_M8 Black-sky albedo for band M8 (1.240 μm) N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_BSA_nir Black-sky albedo for NIR broadband (0.865 μm) N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_BSA_shortwave Black-sky albedo for shortwave broadband (1.61 μm) N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_BSA_vis Black-sky albedo for vis broadband (0.64 μm) N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_WSA_DNB White-sky albedo for Day/Night band (0.7 μm) N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_WSA_M1 White-sky albedo for band M1 (0.412 μm) N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_WSA_M10 White-sky albedo for band M10 (1.61 μm) N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_WSA_M11 White-sky albedo for band M11 (2.25 μm) N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_WSA_M2 White-sky albedo for band M2 (0.445 μm) N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_WSA_M3 White-sky albedo for band M3 (0.488 μm) N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_WSA_M4 White-sky albedo for band M4 (0.555 μm) N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_WSA_M5 White-sky albedo for band M5 (0.672 μm) N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_WSA_M7 White-sky albedo for band M7 (0.865 μm) N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_WSA_M8 White-sky albedo for band M8 (1.240 μm) N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_WSA_nir White-sky albedo for NIR broadband (0.865 μm) N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_WSA_shortwave White-sky albedo for shortwave broadband (1.61 μm) N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
Albedo_WSA_vis White-sky albedo for vis broadband (0.64 μm) N/A 16-bit signed integer 32767 N/A 0 to 1000 0.001
BRDF_Albedo_Uncertainty BRDF inversion information N/A 16-bit unsigned integer 32767 N/A 0 to 32766 0.001
BRDF_Quality BRDF and albedo quality information N/A 8-bit unsigned integer 255 N/A 0 to 5 N/A
Local_Solar_Noon Local solar noon zenith angle Degree 8-bit unsigned integer 255 N/A 0 to 90 N/A
Percent_Inputs Percent finer resolution data which contributed to the CMG Percent 8-bit unsigned integer 255 N/A 0 to 100 N/A
Percent_Snow Percent of underlying data flagged as snow Percent 8-bit unsigned integer 255 N/A 0to 100 N/A

Quality bit index

Value Description
0 Best quality, 100% with full inversions
1 Good quality, 75% or more with best full inversions and 90% or more with full inversions
2 Relative good quality, 75% or more with full inversions
3 Mixed, 75% or less full inversions and 25% or less fill values
4 All magnitude inversions or 50% or less fill values
5 50% or more fill values
255 Fill value

Product Quality

The quality and inversion status of the majority of the underlying 30 arc second pixels is provided as well as the percentage of the underlying pixels that were present or were snow covered. Therefore, quality should be considered when using this product for quantitative results. Product accuracy/uncertainty information can be found in section 4 of the Algorithm Theoretical Basis Document (ATBD).

Known Issues

The VIIRS Land Surface Reflectance product (VNP09) flags a larger number of retrievals as ‘High Aerosol’ in the quality layer as compared to the MODIS reflectance product. The inaccurately flagged high aerosol quality flags cause the BRDF retrieval algorithm to incorrectly reject the observations and switch from full inversion (high quality retrieval) to magnitude inversion (low quality retrieval) in the mid to high latitude, arid lands, and tropical vegetative regions.

Documentation

Using the Data

Tools

Citation

DOI: 10.5067/VIIRS/VNP43C3.001

About the Image

VIIRS RGB albedo data from the VNP43C3 global product acquired on January 1, 2017.

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