Recent activities in the European Community for the creation and analysis of global AVHRR data sets

This paper describes recent activities at the Commission of the European Communities' Joint Research Centre (CEC-JRC) concerning the design of an Advanced Very High Resolution Radiometer (AVHRR) database for global climate and environmental studies (global change). Much of this work has concentrated on pre-processing of long-term AVHRR Global Area Coverage (GAC) data sets, with particular emphasis placed on the continent of Africa. To date, these data have been used to produce the Normalized Difference Vegetation Index, channel 2 reflectance, channel 3 and 4 brightness temperatures, an approximate surface temperature and a cloud probability image on a daily basis from April 1983 to January 1990 for the whole African continent at a resolution of 5 km. The remaining data from the entire GAC time series (July 1981 to the present) will be processed by early 1994. These data will be made available to the international research community through the CEC and European Space Agency initiative, the Centre for Earth Observation. The data sets have already provided new information concerning inter- and intra-annual variations in vegetation fire dynamics for Africa and have been used to derive forest seasonality information through the JRC's thematic projects' TRopical Ecosystem and Environment observations by Satellite (TREES) and Fire In global Resource and Environmental monitoring (FIRE).