The SAREDA (SArgassum Evolving Distribution in the Atlantic) algorithm performs a contextual detection of Sargassum using the Alternative Floating Algae Index (AFAI) (Wang and Hu, 2016). The AFAI deviation with respect to the local background is used to retrieve the Sargassum area coverage, i.e. the fraction of MODIS pixels covered with Sargassum. Daily gridded 1km and 5km composites are derived from MODIS-Terra and MODIS-Aqua instantaneous retrievals.

Within the framework of the SAREDA project, supported by TOSCA-CNES and IRD, the MIO has partnered with the AERIS cluster and its ICARE data and services centre specialised in the massive exploitation of Earth observation spatial data, for the processing of data. GeoID-OCEAN contributed to the implementation of the prototype processing chain.

References :

- Descloitres, J.; Minghelli, A.; Steinmetz, F.; Chevalier, C.; Chami, M.; Berline, L. Revisited Estimation of Moderate Resolution Sargassum Fractional Coverage Using Decametric Satellite Data (S2-MSI). Remote Sens. 2021, 13, 5106. https://doi.org/10.3390/rs13245106

- Podlejski, W. et al. (2022) Filtering out false Sargassum detections using context features. Frontiers in Marine Science. 9:960939. https://doi.org/10.3389/fmars.2022.960939