Retrieving absorption coefficients of multiple phytoplankton pigments from hyperspectral remote sensing reflectance measured over cyanobacteria bloom waters

Light absorption by phytoplankton pigments plays an important role not only in photosynthesis but also in modulating the appearance of water color. Some pigments are markers of phytoplankton classes or species. To better characterize phytoplankton, an inversion model is developed to retrieve the absorption coefficients of multiple pigments from hyperspectral remote sensing reflectance. In the model, the Gaussian functions proposed by Hoepffner and Sathyendranath (1991) were refined and implemented for the estimation of the absorption coefficients of multiple pigments. Application of the inversion model to remote sensing measurements made in cyanobacteria bloom waters resulted in the absorption coefficients of chlorophylls a, b, and c, carotenoid, phycoerythrin, and phycocyanin with the mean absolute relative error under 32% for wavelengths between 400 nm and 700 nm. The results indicate that it is feasible to retrieve the absorption coefficients of multiple pigments from hyperspectral remote sensing reflectance as long as the pigments make adequate contributions to the total absorption coefficient.