Coastcolour Algorithm for the Atmospheric Correction and the Retrieval of Optical Properties of Coastal Waters
Doerffer, Roland1; Brockmann, Carsten2; Santer, Richard3; Röttgers, Rüdiger4; Pinnock, Simon5
1Brockmann-Consult / HZG, GERMANY; 2Brockmann-Consult, GERMANY; 3Université Littoral, FRANCE; 4Helmholtz-Zentrum-Geesthacht, GERMANY; 5ESA, ITALY
For the DUE Coastcolour project of ESA it was necessary to develop algorithms for atmospheric correction and the retrieval of water optical properties and constituents, which cover a large range of optical water types from clear coastal water up to the extreme of turbid estuarine water. Furthermore, it was necessary to identify cases, which are out of scope of these algorithms. The algorithms are based on artificial neural networks, which have been trained with simulated reflectance spectra, which in turn are based on an analysis of optical water types. Two different versions of retrieval algorithms for the water part have been designed, one with a neural network, which comprises all types of water. The other version includes a classification and separate neural networks for each optical water type. The performances of these algorithms and examples for various coastal sites will be demonstrated.