A Statistical Algorithm for Estimating Chlorophyll Concentration in the New Caledonian Lagoon

Remote Sensing

Cécile Dupouy¹  Morgan Mangeas²  Jérôme Lefèvre²  Touraivane³  Guillaume Wattelez³  Robert Frouin⁴ 

[1] Aix-Marseille University, CNRS/INSU, University of Toulon, IRD, Mediterranean Institute of Oceanography (MIO), UM 110, Marseille 13288, France;Institut de Recherche Pour le Développement (IRD), BP A5 98848 Nouméa CEDEX 98848, New Caledonia;Sciences and Technologies Department, University of New Caledonia, Nouville Campus BP R4, Nouméa CEDEX 98851, New Caledonia;Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92037, USA;

关键词: chlorophyll-a concentration;    MODerate resolution Imaging Spectroradiometer (MODIS);    ocean color;    remote sensing;    statistical algorithm;    oligotrophic waters;    New Caledonia;    coral lagoon;   

DOI  :  10.3390/rs8010045

来源: DOAJ

【 摘 要 】

Spatial and temporal dynamics of phytoplankton biomass and water turbidity can provide crucial information about the function, health and vulnerability of lagoon ecosystems (coral reefs, sea grasses, etc.). A statistical algorithm is proposed to estimate chlorophyll-a concentration ([chl-a]) in optically complex waters of the New Caledonian lagoon from MODIS-derived “remote-sensing” reflectance (Rrs). The algorithm is developed via supervised learning on match-ups gathered from 2002 to 2010. The best performance is obtained by combining two models, selected according to the ratio of Rrs in spectral bands centered on 488 and 555 nm: a log-linear model for low [chl-a] (AFLC) and a support vector machine (SVM) model or a classic model (OC3) for high [chl-a]. The log-linear model is developed based on SVM regression analysis. This approach outperforms the classical OC3 approach, especially in shallow waters, with a root mean squared error 30% lower. The proposed algorithm enables more accurate assessments of [chl-a] and its variability in this typical oligo- to meso-trophic tropical lagoon, from shallow coastal waters and nearby reefs to deeper waters and in the open ocean.

【 授权许可】

Unknown