S-NPP Product Descriptions: VNP43IA3N

Last update: November 20, 2023

Data Set Short Name:
VNP43IA3N

Data Set Long Name:
VIIRS/NPP Albedo Daily L3 Global 500 m SIN Grid NRT

Platform:
Suomi National Polar-orbiting Partnership (S-NPP)

Instrument:
Visible Infrared Imaging Radiometer Suite (VIIRS)

Product Description:
The Near Real Time (NRT) Suomi National Polar-Orbiting Partnership (S-NPP) NASA Visible Infrared Imaging Radiometer Suite (VIIRS) Bidirectional Reflectance Distribution Function (BRDF) and Albedo (VNP43MA3N) product provides albedo values at 500 meter (m) resolution for the bihemispherical reflectance white-sky albedos (WSA) and directional hemispherical reflectance black-sky albedos (BSA) at local solar noon. The VNP43MA1N product is produced daily using 16-day VIIRS data (i.e., the current day and the previous 15 days). 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 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).

The VNP43IA3N product provides a total of nine SDS layers including: BSA, WSA, and mandatory quality layers for VIIRS imagery bands: I1, I2, and I3. A low-resolution browse image is also available showing retrievals of WSA for band I1 in JPEG format.

file_naming_convention = "VNP43IA3N.AYYYYDDD.hXXvYY.CCC.YYYYDDDHHMMSS.h5

• AYYYYDDD = Acquisition Year and Day of Year
• HHMM = Hour and minute of acquisition
• hXXvYY = Sinusoidal Tile Identifier (horizontalXXverticalYY)
• CCC = Collection Version number
• YYYYDDDHHMMSS = Julian Date and time of Production in Year, Day of Year, hour, minute, and seconds
• h5 = HDF-EOS (version 5) file format

Production Frequency:
~460 file per day

Spatial Coverage:
Global

Spatial Resolution:
500 m

File Size (MB):
~38

Citation:

Dataset Originator/Creator:
NASA Suomi-NPP Land Science Team/Land, Atmosphere Near real-time Capability for EOS (LANCE)Moderate Resolution Imaging Spectroradiometer (MODIS)

Data Authors:
Dr. Crystal B. Schaaf

Dataset DOI:
http://dx.doi.org/10.5067/VIIRS/VNP43IA3N.002