Global 1km products of surface downward shortwave radiation and photosynthetically active radiation from MODIS

High spatial resolution data sets of surface downward shortwave radiation (DSR) and photosynthetically active radiation (PAR) are needed by many land applications. Most of the existing DSR or PAR products are generated for climatic studies and typically have coarse spatial resolutions that cannot meet the requirement of land user community. Funded by NASA, we develop a global high resolution MODIS products (MCD18) of DSR and PAR over land surfaces. The Collection 6 MCD18 products are available at the spatial resolution of 5km, and the Collection 61 DSR and PAR products further improve the spatial resolution to 1km. The MCD18 products contain instantaneous DSR and PAR corresponding to the MODIS overpass time, as well as the interpolated 3-hourly DSR and PAR values. In this presentation, we will first review the progress in remote sensing of DSR and PAR and summarize the approach used in the MCD18 production. We will then introduce our recent progress on the algorithm refinement and product assessment.