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Description
The MOD17A2HGF Version 6.1 Gross Primary Productivity (GPP) product is a cumulative 8-day composite of values with 500 meter (m) pixel size based on the radiation use efficiency concept that can be potentially used as inputs to data models to calculate terrestrial energy, carbon, water cycle processes, and biogeochemistry of vegetation. The Terra Moderate Resolution Imaging Spectroradiometer (MODIS) data product includes information about GPP and Net Photosynthesis (PSN). The PSN band values are the GPP less the Maintenance Respiration (MR). The data product also contains a PSN Quality Control (QC) layer. The quality layer contains quality information for both the GPP and the PSN.
The MOD17A2HGF will be generated at the end of each year when the entire yearly 8-day MOD15A2H is available. Hence, the gap-filled MOD17A2HGF is the improved MOD17, which has cleaned the poor-quality inputs from 8-day Leaf Area Index and Fraction of Photosynthetically Active Radiation (FPAR/LAI) based on the Quality Control (QC) label for every pixel. If any LAI/FPAR pixel did not meet the quality screening criteria, its value is determined through linear interpolation. However, users cannot get MOD17A2HGF in near-real time because it will be generated only at the end of a given year.
Known Issues
Operational and uncertainty issues are provided under Section 2 in the User Guide.
The following changes and improvements were implemented for inputs to MODIS Version 6.1 GPP data products: (1) Version 6.1 Level-1B (L1B) products have been improved by undergoing various calibration changes that include: changes to the response-versus-scan angle (RVS) approach that affects reflectance bands for Aqua and Terra MODIS, corrections to adjust for the optical crosstalk in Terra MODIS infrared (IR) bands, and corrections to the Terra MODIS forward look-up table (LUT) update for the period 2012 – 2017, (2) A polarization correction has been applied to the L1B Reflective Solar Bands (RSB), and (3) The product uses Climatology Leaf Area Index (LAI) and Fraction of Photosynthetically Active Radiation (FPAR) as back up to the operational LAI/FPAR.
Land Processes Distributed Active Archive Center (LP DAAC)
,
MODIS Adaptive Processing System, Terrestrial Information Systems Laboratory, Earth Sciences Division, Science and Exploration Directorate, Goddard Space Flight Center, NASA (NASA/GSFC/SED/ESD/TISL/MODAPS)
Concept ID
C2565791029-LPCLOUD
Data State
ACTIVE
Number of Files/Granules
347140
Processing Level
4
Published
Updated
Science Keywords
Photosynthesis
,
Primary Production
,
VEGETATION PRODUCTIVITY
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.
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Citation Copied
Running, S., & Zhao, M. (2021). MODIS/Terra Gross Primary Productivity Gap-Filled 8-Day L4 Global 500m SIN Grid V061 [Data set]. NASA Land Processes Distributed Active Archive Center. https://doi.org/10.5067/MODIS/MOD17A2HGF.061 Date Accessed: 2026-04-30
Running, Steve, and Maosheng Zhao. “MODIS/Terra Gross Primary Productivity Gap-Filled 8-Day L4 Global 500m SIN Grid V061.” NASA Land Processes Distributed Active Archive Center, 2021. doi:10.5067/MODIS/MOD17A2HGF.061. Date Accessed: 2026-04-30
Running, Steve, and Maosheng Zhao. MODIS/Terra Gross Primary Productivity Gap-Filled 8-Day L4 Global 500m SIN Grid V061. NASA Land Processes Distributed Active Archive Center, 2021, doi:10.5067/MODIS/MOD17A2HGF.061. Date Accessed: 2026-04-30
File Naming Convention
MOD17A2HGF.A2024361.h14v02.061.2025011052502.hdf
The file name begins with the Product Short Name (MOD17A2HGF) followed by the Julian Date of Acquisition formatted as AYYYYDDD (A2024361), the Tile Identifier which is horizontal tile and vertical tile provided as hXXvYY (h14v02), the Version of the data collection (061), the Julian Date and Time of Production designated as YYYYDDDHHMMSS (2025011052502), and the Data Format (hdf).
Fraction Of Absorbed Photosynthetically Active Radiation (fapar), Leaf Area Index (LAI), Plant Phenology, Enhanced Vegetation Index (EVI), Photosynthesis, Primary Production, VEGETATION PRODUCTIVITY, Vegetation Index, Normalized Difference Vegetation Index (NDVI), Land Use/Land Cover Classification
The table below lists the variables contained within a single granule for this
dataset. Variables often contain observed or derived geophysical measurements
collected from a variety of sources, including remote sensing instruments on
satellite and airborne platforms, field campaigns, in situ measurements, and
model outputs. The terms variable, parameter, scientific data set, layer, and band
have been used across NASA’s Earth science disciplines; however, variable is the
designated nomenclature in NASA’s Common Metadata Repository (CMR).
Variable metadata attributes such as Name, Description, Units, Data Type, Fill
Value, Valid Range, and Scale Factor allow users to efficiently process and analyze
the data. The full range of attributes may not be applicable to all variables.
Additional information on variable attributes is typically available in the data,
user guide, and/or other product documentation.
For questions on a specific variable, please use the Earthdata Forum.