The NASA/NOAA Suomi National Polar-orbiting Partnership (Suomi NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) Gross Primary Productivity (GPP) and Net Photosynthesis (PSN) Gap-Filled (VNP17A2GF) Version 2 product is a cumulative composite of GPP values based on the radiation use efficiency concept that is potentially used as inputs to data models to calculate terrestrial energy, carbon, water cycle processes, and biogeochemistry of vegetation. VNP17A2GF is an 8-day composite at 500 meters (m) spatial resolution delivered as a gridded Level 4 (L4) product in Sinusoidal projection.
The VNP17A2GF will be generated at the end of each year when the entire yearly 8-day VNP15A2H is available. Hence, the gap-filled VNP17A2GF is the improved VNP17A2, 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 VNP17A2GF in near-real time because it will be generated only at the end of a given year.
Provided in the VNP17A2GF product are three variables for GPP, PSN, along with a quality control variable. A low resolution browse image for GPP is also available for each VNP17A2GF granule.
Known Issues
* For complete information about known issues please refer to the MODIS/VIIRS Land Quality Assessment website.