Traitement d'images satellitaires appliqué à la cartographie numérique quantitative de la circulation océanique superficielle

Abstract : This work demonstrates that ocean surface currents may be mapped using a couple of temperature maps derived from satellite data and the heat equation reduced to instationary advection of heat. Temperature maps originate from the AVHRR sensors abord the NOAA series of satellites. Solving the equation requests several steps. Satellite data must be carefully calibrated and atmospheric effects must be correced. Temperature images must be then navigated in order to make them superimposable. They are filtered to smooth out high frequencies. Averaging the two maps yields the horizontal gradient and their difference yields the time derivative. Interpolation of isotherms increases the number of points for solving the equation for a better mapping. The stream field is determined along the isotherms hat intercept a set of points where the stream function is known. Examples are shown for an eddy of the Gulf Stream and surface current in the Gulf of Lions. This method is difficult to set up because the number of points that can be used for mapping is often small and the resulting map does not offer a good geographical coverage.
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Brigitte Bianchi. Traitement d'images satellitaires appliqué à la cartographie numérique quantitative de la circulation océanique superficielle. Traitement du signal et de l'image [eess.SP]. Université de Nice Sophia-Antipolis, 1988. Français. ⟨pastel-00956606⟩

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