MOD17A2HGF v006

MODIS/Terra Gross Primary Productivity Gap-Filled 8-Day L4 Global 500 m SIN Grid

PI: Steve Running


The MOD17A2HGF Version 6 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 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.

read more


Improvements/Changes from Previous Versions

  • The product uses updated Biome Property look-up tables (BPLUT) and an updated version of the daily Global Modeling and Assimilation Office (GMAO) meteorological data.
  • The products are now generated at the native resolution of 500 m using the Moderate Resolution Imaging Spectroradiometer (MODIS) Leaf Area Index(LAI)/Fraction of Photosynthetically Active Radiation (FPAR) (MOD15A2H) 8-day composite at 500 m resolution.

Product Maturity

Stage 3 validation has been achieved for MOD17 products.

Collection and Granule


Characteristic Description
CollectionTerra MODIS
File Size3.938 MB
Temporal ResolutionMulti-Day
Temporal Extent2000-01-01 to Present
Spatial ExtentGlobal
Coordinate SystemSinusoidal
File FormatHDF-EOS
Geographic Dimensions1200 km x 1200 km


Characteristic Description
Number of Science Dataset (SDS) Layers3
Columns/Rows2400 x 2400
Pixel Size500 m


SDS Name Description Units Data Type Fill Value No Data Value Valid Range Scale Factor
Gpp_500m Gross Primary Productivity kgC/m²/8day 16-bit signed integer 32761 to 32767 N/A 0 to 30000 0.0001
PsnNet_500m Net Photosynthesis kgC/m²/8day 16-bit signed integer 32761 to 32767 N/A -30000 to 30000 0.0001
Psn_QC_500m Quality control Indicators Bit Field 8-bit unsigned integer 255 N/A 0 to 254 N/A

Non-Terrestrial Fill Value Classes

Value Description
32761 Land cover assigned as "unclassified" or not able to determine
32762 Land cover assigned as urban/built-up
32763 Land cover assigned as "permanent" wetlands/inundated marshland
32764 Land cover assigned as perennial snow, ice
32765 Land cover assigned as barren, sparse veg (rock, tundra, desert)
32766 Land cover assigned as perennial salt or inland fresh water
32767 Fill Value

Product Quality

For the year-end gap-filled MOD17A2HGF, users may ignore the QC data layer because cloud-contaminated LAI/FPAR gaps have been temporally filled prior to calculation.

Mappings for the Psn_QC_500m layer and an explanation of how to interpret this information are provided under Section 4.1 in the User Guide.

The quality layer is stored in an efficient bit-encoded manner. The unpack_sds_bits executable from the LDOPE Tools is available to the user community to help parse and interpret this layer.

Additional information on the Collection 5.5 improved 1 km MOD17 product by the Numerical Terradynamic Simulation Group (NTSC) at the University of Montana and a comparison with the MOD17HGF products are provided in MOD17HGF_vs_NTSG.pdf.

Known Issues

Operational and uncertainty issues are provided under Section 2 in the User Guide. Please refer to the MODIS Land Quality Assessment website for complete information about MOD17A2HGF known issues..


Using the Data

Access Data


DOI: 10.5067/MODIS/MOD17A2HGF.006

About the Image

Terra MODIS gross primary productivity (GPP) data from the MOD17A2HGF product over Northern Argentina from January 1 - 8, 2003.

View full-size image