Automatic spline-smoothing approach applied to denoise Moroccan resistivity data phosphate deposit “disturbances” map
Lissage automatique par spline fonction applique au “debruitage” de la carte des resistivites des “derangements” des phosphates Marocains
DOI:
https://doi.org/10.15446/ing.investig.v28n1.14877Keywords:
smoothing, automatic, spline, resistivity, Schlumberger, phosphate, Morocco (en)résistivité, spline, optimal, lissage, phosphate, « dérangement », Maroc (es)
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This paper focuses on presenting a method which is able to filter out noise and suppress outliers of sampled real functions under fairly general conditions. The automatic optimal spline-smoothing approach automatically determines how a cubic spline should be adjusted in a least-squares optimal sense from an a priori selection of the number of points defining an adjusting spline, but not their location on that curve. The method is fast and easily allowed for selecting several knots, thereby adding desirable flexibility to the procedure. As an illustration, we apply the AOSSA method to Moroccan resistivity data phosphate deposit “disturbances'' map. The AOSSA smoothing method is an efficient tool in interpreting geophysical potential field data which is particularly suitable in denoising, filtering and analyzing resistivity data singularities. The AOSSA smoothing and filtering approach was found to be consistently useful when applied to modeling surface phosphate “disturbances”.
Dans le présent travail, nous présentons une nouvelle méthode de “débruitage” et de filtrage utilisant des fonctions analytiques échantillonnées. A partir d’un échantillon de points d’ajustement de la fonction spline utilisée, la méthode dite «Automatic Optimal Spline Smoothing Approach » ou AOSSA permet de déterminer automatiquement l’ajustement par fonction spline d’ordre 3 au sens des moindres carrés, sans pour autant connaître la localisation des points de l’échantillon sur la courbe. Cette méthode rapide permet facilement de choisir différents points de lissage avec une certaine flexibilité de la procédure. En guise d’illustration nous avons appliqué la méthode AOSSA à la carte des données d’anomalies de résistivités correspondantes aux « dérangements » des phosphates maro cains. La méthode de lissage et de filtrage AOSSA s’est avérée être un outil potentiellement efficace pour l'optimisation des surfaces correspondantes aux zones des « dérangements » des phosphates marocains.
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Copyright (c) 2008 Saad Bakkali, Lahcen Bahi
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