Improving Satellite Estimates Of The Fraction Of Absorbed Photosynthetically Active Radiation Through Integration

The fraction of absorbed photosynthetically active radiation (FAPAR) is a critical input in many climate and ecological models. The targeted accuracy of FAPAR products is 10% or 0.05 for many applications. However, most current FAPAR products do not meet such requirements, and further improvements are still needed. In this study, a data fusion scheme based on the multiple resolution tree (MRT) approach is developed to integrate multiple satellite FAPAR estimates at site and regional scales. The fusion scheme removed the bias in FAPAR estimates and resulted in a 15% increase in the R-2 and 3% reduction in the root mean square error (RMSE) compared with the average of individual FAPAR estimates. The regional scale fusion filled in the missing values, and provided spatially consistent FAPAR distributions at different resolutions.