Performance of Fapar Operational Products Derived from Meris at the Full and Reduced Resolutions

This paper discusses the validation of the operational Medium Resolution Imaging Spectrometer (MERIS) land product which corresponds to the biophysical variable of the Fraction of Absorbed Photosynthetically Active Radiation (FAPAR). The FAPAR value is currently and automatically estimated from MERIS data at reduced resolution and it can be computed using the full resolution using the same physically-based algorithm. The quality of the MERIS FAPAR products capitalizes on the availability of MERIS data since June 2002. The proposed validation exercise is to assess the accuracy of FAPAR product by comparing the FAPAR MERIS values to similar products generated by other independent sensors like the Seaviewing Wide Field-of-view Sensor (SeaWiFS), the MODerate Resolution Imaging Spectro-radiometer (MODIS) and LANDSAT 7 ETM+ against groundestimates of FAPAR which have been performed over various types of land.