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Abstract

Anisotropic filtering to improve the geodetic determination of the Surface Geostrophic Currents: Edge Enhancing Diffusion

Dr Jose M SANCHEZ-REALES(1), Dr Ole Baltazar ANDERSEN(2), Dr Isabel VIGO(1)

(1) University of Alicante, Spain
(2) Danish National Space Center, Denmark

Session theme: The Geoid, Mean Sea Surfaces and Mean Dynamic Topography

  • poster

    Abstract

    The Surface Geostrophic Currents (SGC) can be determined from the gradient of the Mean Dynamic Topography (MDT) which is defined as the mean sea surface height referenced on the Earth's geoid. Due to the noise in the MDT, particularly for short space wave lengths, some filtering is required before the SGC computation. Since the SGC have a strong directional behaviour (emphasized when the current increases) anisotropic filtering would be preferred for the case. Here we deal with the capabilities of the Edge Enhancing Diffusion (EED) filters for filtering the MDT in order to improve the computation of the SGC. It is proved how this method conserves all the advantages that the non-linear isotropic filters have over the standard linear isotropic Gaussian filters. Moreover, the EED is shown to be more stable and almost independent of the local errors. This fact makes this filtering strategy more appropriated when filtering noisy surfaces.

     
    Corresponding author:

      Dr Jose M Sanchez-Reales
      Univerisity of Alicante
      Departamento de Matemática Aplicada
      Escuela Politécnica Superior, Edificio 2
      Universidad de Alicante
      Ctra Sant Vicent del Raspeig s/n
      E03690 San Vicente del Raspeig - Alicante - España
      03690 Alicante
      Spain
      E-mail:
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