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	Provedor de dados ArchiMer (2) Autor Le Chenadec, Gilles (2) Boucher, Jean-marc (1) Lurton, Xavier (1) Palavra-chave Backscattering Strength (1) Champs de Markov (1) Image segmentation (1) Inverse Problem (1) K distribution (1) Markov Random Field (1) Modélisation géoacoustique et géostatistique des fonds marins (1) Méthodes SVM (1) Problèmes inverses (1) Rétrodiffusion (1) Seafloor classification (1) Seafloor geoacoustical and geostatistical Model (1) Segmentations d'images sonar (1) Signal Processing (1) Sonar statistical analysis (1) Spatial Statistics (1) Statistiques spatiales (1) Support Vector Machines (1) Traitement du signal (1) Mais... Tipo do documento Text (2) Ano 2007 (1) 2004 (1) País France (2) Idioma Francês (1) Inglês (1)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 2 Primeira ... 1 ... Última Analyse de descripteurs énergétiques et statistiques de signaux sonar pour la caractérisation des fonds marins ArchiMer Le Chenadec, Gilles. Sonar systems own the attractive ability to simultaneously provide a bathymetric map and a sonar image of large insonified seabed areas. Recorded data information, the backscattered energy is well known as an essential clue about the seabed nature and roughness. This PhD thesis lie within a seafloor characterization project using acoustical methods. The objectives are the data exploitation of two sonar systems (a multibeam echosounder and sidescan sonar) ; both operate at a high frequency (around 100 kHz) but their survey geometry is different. Sonar images are first analyzed and reveal artefacts due to geometry of the sonar system and array patterns, leading to difficulties in their geological interpretation. In the context of the sediment discrimination,... Tipo: Text Palavras-chave: Support Vector Machines; Markov Random Field; Image segmentation; Spatial Statistics; Signal Processing; Inverse Problem; Backscattering Strength; Seafloor geoacoustical and geostatistical Model; Méthodes SVM; Champs de Markov; Segmentations d'images sonar; Statistiques spatiales; Traitement du signal; Problèmes inverses; Rétrodiffusion; Modélisation géoacoustique et géostatistique des fonds marins. Ano: 2004 URL: http://archimer.ifremer.fr/doc/2004/these-242.pdf Angular dependence of K-distributed sonar data ArchiMer Le Chenadec, Gilles; Boucher, Jean-marc; Lurton, Xavier. Backscattered signal statistics are widely used for target detection and seafloor characterization. The K-distribution shows interesting properties for describing experimental backscattered intensity statistics. In addition to the fact that its probability distribution function accurately fits actual sonar data, it advantageously provides a physical interpretation linked to the backscattering phenomenon. Sonar systems usually record backscattered signals from a wide angular range across the ship's track. In this context, previous studies have shown that backscatter statistics strongly depend on the incidence angle. In this paper, we propose an extension of previous works to model the angular evolution of the K-distribution shape parameter. This evolution... Tipo: Text Palavras-chave: K distribution; Sonar statistical analysis; Seafloor classification. Ano: 2007 URL: http://archimer.ifremer.fr/doc/2007/publication-2599.pdf Registros recuperados: 2 Primeira ... 1 ... Última

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