Evaluation of the NOAA/NASA Pathfinder AVHRR Land Data Set for global primary production modelling

The new NOAA/NASA Pathfinder Advanced Very High Resolution Radiometer (AVHRR) Land Data Set has been used to drive the GLObal Production Efficiency (GLO-PEM) primary production model for vegetation at a spatial resolution of 8 x 8 km for the entire land cover of the Earth. The principal advantage of the Pathfinder data was the organization of a vast archive of AVHRR global area coverage (GAG) data into a consistent data set in which post-flight sensor calibrations and atmospheric corrections have been applied. The principal difficulties arose from the compositing of thermal channels into 10-day composites using a maximum Normalized Difference Vegetation Index (NDVI) criterion, the failure of the cloud screening procedure, the absence of coastal data, and some aspects of the data format. Overall the data set represents a significiant advance over the NOAA Global Vegetation Index (GVI), which has long been the only publicly available, complete global data set.