GlobColour

The aim of the Data User Element GlobColour project was to develop and demonstrate an EO-based service supporting global ocean carbon-cycle research. The project provided scientists with a long time-series of consistently calibrated global ocean colour information, according to requirements specified by the global ocean colour user community, as represented by the user group. GlobColour successfully put in place the capacity to continue the ocean colour service in the future, concluding with service transfer to the EC funded GMES Marine Core Service.

GlobColour demonstrated the production of a merged data set from several different satellite data streams: MERIS, SeaWiFS and Aqua / MODIS. The objective was to combine these data streams in such a way that the output product is as far as possible independent of the input data source.

To achieve this, a characterisation of each sensor's performance was first made, including an analysis of the best available retrieval algorithms. Data-merging methods starting from both radiance and derived bulk properties (such as surface chlorophyll concentration) were tested. The final choice of which merging algorithm to implement was made following an algorithm intercomparison and trade-off analysis. A thorough validation of the final products against in-situ measurements was performed following well defined protocols, such as those developed and demonstrated under the SIMBIOS programme. To show the potential for supporting operational oceanography, the data merging system developed was used to provide a demonstration global NRT ocean colour service based on ENVISAT/MERIS and AQUA/MODIS.