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Description

The NOAA-20 Visible Infrared Imaging Radiometer Suite (VIIRS) Photosynthetically Active Radiation (PAR) Level 3 Climate Modeling Grid (CMG) product produced at 0.05 degree pixel resolution at daily intervals. PAR is the incident solar radiation in the visible spectrum (400-700 nanometers) and is a significant variable in land surface models (LSMs), receiving increased attention due to its importance for the management and operation of solar energy systems.

The VJ118 algorithm adapts the narrowband look-up table (LUT) approach to estimate PAR. The LUTs consider different types of loadings of aerosols and clouds at a variety of illumination/viewing geometry. The Algorithm Theoretical Basis Document (ATBD) is forthcoming and will provide additional details regarding the methodology used to create the data.

The VJ118C2 product is aggregated from VJ118A2 files and includes one set of global 3-hour PAR variables and one set of daily mean PAR.

Version Description

Collection Version 2 Processing and Reprocessing

Product Summary

Platforms
NOAA-20
Instruments
VIIRS
Spatial Extent
N: 90 S: -90 E: 180 W: -180
Spatial Resolution
5600 Meters x 5600 Meters
Geographic Region
GLOBAL
Coordinate System
CARTESIAN
Granule Spatial Representation
GEODETIC
Temporal Extent
2018-01-05 to Present
Temporal Resolution
1 Day
Data Partner
Land Processes Distributed Active Archive Center (LP DAAC)
Land Science Investigator-led Processing System, Terrestrial Information Systems Laboratory, Earth Sciences Division, Sciences and Exploration Directorate, Goddard Space Flight Center, NASA (NASA/GSFC/SED/ESD/TISL/LandSIPS)
Concept ID
C2631841553-LPCLOUD
Data State
ACTIVE
Processing Level
3
Published
Updated
Science Keywords
Reflectance,
Albedo,
Anisotropy

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.

Copy Citation

Wang, D. (2025). VIIRS/JPSS1 Photosynthetically Active Radiation Daily L3 Global 0.05Deg CMG V002 [Data set]. NASA Land Processes Distributed Active Archive Center. https://doi.org/10.5067/VIIRS/VJ118C2.002 Date Accessed: 2025-10-09

File Naming Convention

VJ118C2.A2025198.002.2025210070105.h5

The file name begins with the Product Short Name (VJ118C2) followed by the Julian Date of Acquisition formatted as AYYYYDDD (A2025198), the Version of the data collection (002), the Julian Date and Time of Production designated as YYYYDDDHHMMSS (2025210070105), and the Data Format (h5).

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