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 Europe an Communities' Joint Research Centre (CEC-JRC) concerning the design of an Advanced Very High Resolution Radiometer (AVHRR) database for gl obal climate and environmental studies (global change). Much of this w ork has concentrated on pre-processing of long-term AVHRR Global Area Coverage (GAC) data sets, with particular emphasis placed on the conti nent of Africa. To date, these data have been used to produce the Norm alized Difference Vegetation Index, channel 2 reflectance, channel 3 a nd 4 brightness temperatures, an approximate surface temperature and a cloud probability image on a daily basis from April 1983 to January 1 990 for the whole African continent at a resolution of 5 km. The remai ning data from the entire GAC time series (July 1981 to the present) w ill be processed by early 1994. These data will be made available to t he international research community through the CEC and European Space Agency initiative, the Centre for Earth Observation. The data sets ha ve 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 pr ojects' TRopical Ecosystem and Environment observations by Satellite ( TREES) and Fire In global Resource and Environmental monitoring (FIRE) .