The MOD17A2H 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 Net Photosynthesis (PSN) band values are the GPP less the Maintenance Respiration (MR).
Reference: LP DAAC - MOD17A2H Version 6