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| Lubac, Bertrand; Loisel, Hubert; Guiselin, Natacha; Astoreca, Rosa; Artigas, L. Felipe; Meriaux, Xavier. |
| Identification of phytoplankton groups from space is essential to map and monitor algal blooms in coastal waters, but remains a challenge due to the presence of suspended sediments and dissolved organic matter which interfere with phytoplankton signal. On the basis of field measurements of remote sensing reflectance (Rrs(λ)), bio-optical parameters, and phytoplankton cells enumerations, we assess the feasibility of using multispectral and hyperspectral approaches for detecting spring blooms of Phaeocystis globosa (P. globosa). The two reflectance ratios (Rrs(490)/Rrs(510) and Rrs(442.5)/Rrs(490)), used in the multispectral inversion, suggest that detection of P. globosa blooms are possible from current ocean color sensors. The effects of chlorophyll... |
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| Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00240/35132/33636.pdf |
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| Loisel, Hubert; Lubac, Bertrand; Dessailly, David; Duforet-gaurier, Lucile; Vantrepotte, Vincent. |
| The impact of the inherent optical properties (IOP) variability on the chlorophyll, Chl, retrieval from ocean color remote sensing algorithms is analyzed from an in situ data set covering a large dynamic range. The effect of the variability of the specific phytoplankton absorption coefficient, a(phy)/Chl, specific particulate backscattering coefficient, b(bp)/Chl, and colored detrital matter absorption to non-water absorption ratio, a(cdm)/a(nw), on the performance of standard operational algorithms is examined. This study confirms that empirical algorithms are highly dependent on the specifics IOP values (especially b(bp)/Chl and a(cdm)/a(nw)): Chl is over-estimated in waters with specific IOP values higher than averaged values, and vice versa. These... |
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| Ano: 2010 |
URL: https://archimer.ifremer.fr/doc/00240/35133/33635.pdf |
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| Gernez, Pierre; Lafon, Virginie; Lerouxel, Astrid; Curti, Cecile; Lubac, Bertrand; Cerisier, Sylvain; Barille, Laurent. |
| At the end of the SPOT4 mission, a four-month experiment was conducted in 2013 to acquire high spatial (20 m) and high temporal (5 days) resolution satellite data. In addition to the SPOT4 (Take5) dataset, we used several Landsat5, 7, 8 images to document the variations in suspended particulate matter (SPM) concentration in the turbid Gironde and Loire estuaries (France). Satellite-derived SPM concentration was validated using automated in situ turbidity measurements from two monitoring networks. The combination of a multi-temporal atmospheric correction method with a near-infrared to visible reflectance band ratio made it possible to quantify SPM surface concentration in moderately to extremely turbid waters (38-4320 g center dot m(-3)), at an accuracy... |
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| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00590/70198/68221.pdf |
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| Novoa, Stefani; Doxaran, David; Ody, Anouck; Vanhellemont, Quinten; Lafon, Virginie; Lubac, Bertrand; Gernez, Pierre. |
| The accurate measurement of suspended particulate matter (SPM) concentrations in coastal waters is of crucial importance for ecosystem studies, sediment transport monitoring, and assessment of anthropogenic impacts in the coastal ocean. Ocean color remote sensing is an efficient tool to monitor SPM spatio-temporal variability in coastal waters. However, near-shore satellite images are complex to correct for atmospheric effects due to the proximity of land and to the high level of reflectance caused by high SPM concentrations in the visible and near-infrared spectral regions. The water reflectance signal ((w)) tends to saturate at short visible wavelengths when the SPM concentration increases. Using a comprehensive dataset of high-resolution satellite... |
| Tipo: Text |
Palavras-chave: Remote sensing; Suspended particulate matter; Coastal waters; River plumes; Multi-conditional algorithm. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00590/70197/68222.pdf |
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