OCEAN Project: the European archive of CZCS historical data
Optical observations of the marine environment have been increasingly used to provide a novel look at a score of bio-geo-chemical and physical processes of the sea. A considerable time series of such data was collected by the Coastal Zone Color Scanner (CZCS) on board the satellite Nimbus-7, from late 1978 to early 1986. In order to exploit this historical dataset, the Ocean Colour European Archive Network (OCEAN) project a joint initiative of the Joint Research Centre (JRC) of the European Commission (EC) and the European Space Agency (ESA) has performed a thorough reappraisal of all (about 18 000) CZCS scenes covering marine regions of European concern. The Project had the specific aims of generating a European ocean colour database from the historical CZCS series, promoting its use in an Application Demonstration Programme (ADP) for selected regions, and last, but not least, developing in Europe a 'network' of scientific groups and facilities in support of current research activities and future space missions. In approaching these tasks, the Project developed specific software tools, integrated into a system named OCEANcode, for the operational processing and management of ocean colour data. Current system developments include tools devoted to the pre-processing of all CZCS data available in Europe (level-1 data), and the generation of appropriate quick-look images; the processing of all suitable data to the final geophysical parameters of interest (level-2 data), by means of algorithms for calibration, atmospheric correction, and pigment concentration derivation; the generation of time series, mosaics and statistical images of such parameters (level-3 data), via image geographic registration, coastal feature matching, and statistical compositing. The OCEAN archives have found applications in a number of studies concerning environmental issues of the European marginal and enclosed seas.