%0 Journal Article
%9 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES
%A Wattelez, G.
%A Dupouy, Cécile
%A Mangeas, Morgan
%A Lefevre, Jérôme
%A Touraivane,
%A Frouin, R.
%T A statistical algorithm for estimating chlorophyll concentration in the New Caledonian lagoon
%D 2016
%L fdi:010066220
%G ENG
%J Remote Sensing
%@ 2072-4292
%K chlorophyll-a concentration ; MODerate resolution Imaging ; Spectroradiometer (MODIS) ; ocean color ; remote sensing ; statistical ; algorithm ; oligotrophic waters ; New Caledonia ; coral lagoon
%K NOUVELLE CALEDONIE ; PACIFIQUE
%M ISI:000369494500026
%N 1
%P art. 45 [23 ]
%R 10.3390/rs8010045
%U https://www.documentation.ird.fr/hor/fdi:010066220
%> https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers16-03/010066220.pdf
%V 8
%W Horizon (IRD)
%X 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 (R-rs). 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 R-rs 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.
%$ 126 ; 036 ; 020