Abstract
The general objective of this work was to conceive algorithms of estimation of two
parameters: chlorophyll-a and turbidity. To validate them, we choosed to compare them to
semi-analytical
algorithms
of
two
sensors
Landsat8
and
Sentinel-2.
In order to do this, the approach was to design two empirical estimation algorithms for
chlorophyll-a and turbidity by performing a calibration of in-situ measurements by
reflectances of OLI and MSI sensors in order to develop color ocean products closer to
reality. To validate them, they were compared to two standard algorithms OC2 Landsat 8 and
OC4E Sentinel-2.
The OC (Ocean Color) algorithms and the Landsat-8 empirical algorithm clearly overestimate
the chlorophyll-a concentration because they are influenced by some optically active
components in seawater (in this case the suspended matter). However, the empirical Sentinel2 algorithm has shown efficiency and better performance, so it has been adopted to resolve
our problem.
This algorithm has been applied to the Landsat-8 and Sentinel-2 satellite measurements of the
reflectance. Then, a comparative study was carried out between the products of the empirical
algorithm estimating chlorophyll and that estimating the turbidity to show the influence of the
turbidity or the fluxes of the suspended matter on Chlorophyll concentration.
Keywords: remote sensing, visible domain, Bou Ismail, chlorophyll-a, turbidity, suspended
matter, Landsat 8, Sentinel-2A.