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    • MODIS/Terra+Aqua Photosynthetically Active Radiation Daily/3-Hour L3 Global 1km SIN Grid V062

    Metadata Updated: September 19, 2025

    The MCD18A2 Version 6.2 is a Moderate Resolution Imaging Spectroradiometer (MODIS) Terra and Aqua combined Photosynthetically Active Radiation (PAR) gridded Level 3 product produced daily at 1 kilometer pixel resolution with estimates of PAR every 3 hours. PAR is incident solar radiation in the visible spectrum (400-700 nanometers) and is an important variable in land-surface models that address a variety of scientific and application issues. The MCD18 products are based on a prototyping algorithm that uses multi-temporal signatures of MODIS data to derive surface reflectance and then calculate incident PAR using the look-up table (LUT) approach. The LUTs consider different types of loadings of aerosols and clouds at a variety of illumination/viewing geometry. Global PAR products are generated from MODIS and geostationary satellite data. Additional details regarding the methodology used to create the data are available in the Algorithm Theoretical Basis Document (ATBD).Provided in the MOD18A2 product are layers for instantaneous PAR array for each individual MODIS overpass and 3-hour PAR array along with a View Zenith Angle layer.Known Issues For complete information about known issues please refer to the MODIS/VIIRS Land Quality Assessment website.Improvements/Changes from Previous Versions MODIS shortwave infrared bands are included in the retrieval algorithm, which significantly reduces estimation uncertainties in cloud- and snow-covered pixels. Inclusion of a new multispectral algorithm has been implemented to replace the blue band retrieval algorithm. An improved climatology of surface spectral and broadband albedo was produced and used in the retrieval algorithm.

    Access & Use Information

    Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

    Downloads & Resources

    Dates

    Metadata Created Date April 11, 2025
    Metadata Updated Date September 19, 2025

    Metadata Source

    Harvested from NASA Data.json

    Other Data Resources

    Additional Metadata

    Resource Type Dataset
    Metadata Created Date April 11, 2025
    Metadata Updated Date September 19, 2025
    Publisher LP DAAC;NASA/GSFC/SED/ESD/TISL/MODAPS
    Maintainer
    Identifier 10.5067/MODIS/MCD18A2.062
    Data Last Modified 2025-09-11
    Category Earth Science
    Public Access Level public
    Bureau Code 026:00
    Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
    Schema Version https://project-open-data.cio.gov/v1.1/schema
    Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
    Harvest Object Id 348f7230-091f-40b0-92bf-5191cafa11fb
    Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
    Harvest Source Title NASA Data.json
    Homepage URL https://search.earthdata.nasa.gov/search?q=C2486282714-LPCLOUD
    Old Spatial {"NorthBoundingCoordinate":90,"WestBoundingCoordinate":-180,"EastBoundingCoordinate":180,"SouthBoundingCoordinate":-90},"CARTESIAN"
    Program Code 026:000
    Source Datajson Identifier True
    Source Hash 7542b6473305eeb700c2597e22b5edc642317416035d8ec826d143e1baf9e380
    Source Schema Version 1.1
    Spatial
    Temporal 2000-02-24/2000-02-24

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