MODIS Terra Net Primary Production Gap-Filled Yearly L4 Global 500m 2004

The MODIS Terra MOD17A3HGF Version 6.1 product provides annual estimates of Gross Primary Productivity (GPP) and Net Primary Productivity (NPP) at 500 m spatial resolution. The dataset is generated by summing all 8-day GPP and Net Photosynthesis (PSN) values from the MOD17A2H product over a given year, where PSN is calculated as GPP minus Maintenance Respiration (MR). The gap-filled product is produced at the end of each year once the complete annual MOD15A2H LAI/FPAR dataset becomes available. Poor-quality LAI/FPAR inputs are identified using quality control flags and replaced through linear interpolation to improve data consistency. Because of this processing approach, the dataset is not available in near-real time and is released only after the full yearly dataset has been completed.