Google Earth Engine ——MOD17A3HGF.006: MOD17A3HGF V6产品提供500米像素分辨率的年度净初级生产力（NPP）Yearly Global 500m

The MOD17A3HGF V6 product provides information about annual Net Primary Productivity (NPP) at 500m 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 diff