Description
The Terra Moderate Resolution Imaging Spectroradiometer (MODIS) 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 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 (https://doi.org/10.5067/modis/mod15a2h.061) 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.
Stage 3 (https://landweb.modaps.eosdis.nasa.gov/cgi-bin/QA_WWW/newPage.cgi?fileName=maturity) validation has been achieved for MOD17 products.
Improvements/Changes from Previous Versions
* The 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.
* A polarization correction has been applied to the L1B Reflective Solar Bands (RSB).
* The product uses Climatology LAI/FPAR as back up to the operational LAI/FPAR.
Resources
| Name | Format | Description | Link |
|---|---|---|---|
| Download this dataset | HTML | The Application for Extracting and Exploring Analysis Ready Samples (AρρEEARS) offers a simple and efficient way to perform data access and transformation processes. | Open resource |
| Get a related visualization | HTML | Browse image for Earthdata Search | Open resource |
| This dataset's landing page | HTML | The LP DAAC product page provides information on Science Data Set layers and links for user guides, ATBDs, data access, tools, customer support, etc. | Open resource |
| Download this dataset | HDF | LP DAAC Data Pool provides direct access to available products via HTTPS. | Open resource |
| View documentation related to this dataset | HTML | The File Specification provides a description of the product file including Scientific Data Sets and their attributes. | Open resource |
| The dataset's project home page | HTML | The LP DAAC website provides detailed information on discovery, distribution, access, and support of land data products. | Open resource |
| View this dataset's algorithm theoretical basis document | The ATBD provides physical theory and mathematical procedures for the calculations used to produce the data products. | Open resource | |
| View this dataset's user's guide | The technical information in the User's Guide enables users to interpret and use the data products. | Open resource | |
| View this dataset's science data product validation documentation | HTML | Validation at stage 3 has been achieved for the MODIS Gross and Net Primary Productivity data products. | Open resource |
| View this dataset's science data product validation documentation | HTML | Further details regarding MODIS land product validation for the MOD17 data products are available from the MODIS Land Team Validation site. | Open resource |
| Use OPeNDAP to access the dataset's data | HTML | Access data via Open-source Project for a Network Data Access Protocol | Open resource |
| Google Scholar search results | HTML | Search results for publications that cite this dataset by its DOI. | Open resource |
| Download this dataset | HDF | Earthdata Search allows users to search, discover, visualize, refine, and access NASA Earth Observation data. | Open resource |