MOD17A3HGF v006

MODIS/Terra Net Primary Production Gap-Filled Yearly L4 Global 500 m SIN Grid


PI: Steve Running

Description

The MOD17A3HGF Version 6 product provides information about annual Net Primary Production (NPP) at 500 meter (m) pixel resolution. Annual NPP is derived from the sum of all 8-day Net Photosynthesis (PSN) products (MOD17A2H) from the given year. The PSN value is the difference of the Gross Primary Productivity (GPP) and the Maintenance Respiration (MR).

The MOD17A3HGF will be generated at the end of each year when the entire yearly 8-day MOD15A2H is available. Hence, the gap-filled MOD17A3HGF is the improved MOD17, which has cleaned the poor-quality inputs from 8-day Leaf Area Index and Fraction of Photosynthetically Active Radiation (LAI/FPAR) 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 MOD17A3HGF in near-real time because it will be generated only at the end of a given year.

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Characteristics

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

Collection

Characteristic Description
CollectionTerra MODIS
DOI10.5067/MODIS/MOD17A3HGF.006
File Size~0.79 MB
Temporal ResolutionYearly
Temporal Extent2000-02-18 to Present
Spatial ExtentGlobal
Coordinate SystemSinusoidal
DatumN/A
File FormatHDF-EOS
Geographic Dimensions1200 km x 1200 km

Granule

Characteristic Description
Number of Science Dataset (SDS) Layers2
Columns/Rows2400 x 2400
Pixel Size500 m

Layers

SDS Name Description Units Data Type Fill Value No Data Value Valid Range Scale Factor
Npp_500m Net Primary Productivity kgC/m²/year 16-bit signed integer 32761 to 32767 N/A -30000 to 32700 0.0001
Npp_QC_500m Quality Control Bits Percent 8-bit unsigned integer 249 to 255 N/A 0 to 100 N/A

Npp_500m 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

Npp_QC_500m Fill Value Classes

Value Description
249 Land cover assigned as "unclassified" or not able to determine
250 Land cover assigned as urban/built-up
251 Land cover assigned as "permanent" wetlands / inundated marshland
252 Land cover assigned as perennial snow, ice
253 Land cover assigned as barren, sparse vegetation (rock, tundra, desert)
254 Land cover assigned as perennial salt or water bodies
255 Fill

Product Quality

Quality for MOD17A3HGF is expressed as a percentage in the Npp_QC_500m science dataset layer. More information on how this value is derived can be found in Section 4.2 of the User Guide.

Known Issues

Operational and uncertainty issues are provided under Section 2 in the User Guide. For complete information about the MOD17A3HGF known issues refer to the MODIS Land Quality Assessment website.

Documentation

Using the Data

Access Data

Citation

DOI: 10.5067/MODIS/MOD17A3HGF.006

About the Image

Terra MODIS net primary productivity (NPP) data from the MOD17A3HGF product over Chile and Argentina, 2003.

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