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	Provedor de dados ArchiMer (3) Autor Hamza, Tasnim (1) Le Chenadec, Gilles (1) Lurton, Xavier (1) Palavra-chave Traitement du signal (3) Signal processing (2) Acoustique sous-marine (1) Backscattering Strength (1) Champs de Markov (1) Communications numériques (1) Communications optiques sous-marines (1) Digital communications (1) Echosounder (1) Image segmentation (1) Inverse Problem (1) Markov Random Field (1) Modélisation géoacoustique et géostatistique des fonds marins (1) Méthodes SVM (1) Optronics (1) Optroniques (1) Photo-multiplicateurs en Silicium (1) Problèmes inverses (1) Propagation (1) Rétrodiffusion (1) Mais... Tipo do documento Text (3) Ano 2017 (1) 2004 (1) 2001 (1) País France (3) Idioma Francês (3)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 3 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 Communications optiques sous-marines : Transmission longue-portée haut-débit et analyse des performances ArchiMer Hamza, Tasnim. Today we are witnessing a growing need to high-rate data transmission in underwater missions in a wide range of application areas. Within this context, traditional cable- or fiber-based communications imply costly deployments with very limited flexibility, andthe conventional acoustic communications offer very low operational performance. Recently, with the development of small and low-cost optoelectronic components and devices, it has become feasible to realize small and compact wireless optical communication transceivers providing unprecedentedly high transmission rates and energy efficiency. However, there still remain several shortcomings of this technology, in particular to attain high data rates over relatively long communication ranges.In order to... Tipo: Text Palavras-chave: Communications optiques sous-marines; Traitement du signal; Communications numériques; Optroniques; Photo-multiplicateurs en Silicium; Underwater optical communications; Signal processing; Digital communications; Optronics; Silicon photo-multipliers.. Ano: 2017 URL: http://archimer.ifremer.fr/doc/00392/50358/51059.pdf Acoustique sous-marine. Présentation et applications ArchiMer Lurton, Xavier. Sound waves are the only practical means of remote investigation and transmission in seawater. All along the XXth century, underwater acoustics became one of the major technologies used for exploration and exploitation of the oceans for scientific, industrial, or military purposes. It is nowadays able to play, inside the oceans, the roles devoted to radio and radar in atmosphere and space, and is widely employed in the fields of navigation, fisheries, defence, oceanography and ocean engineering. This book presents, in a clear and concise way, the basic physical phenomena governing underwater acoustical waves, the general features of sonar systems, and an overview of their applications. Tipo: Text Palavras-chave: Acoustique sous-marine; Propagation; Traitement du signal; Sonar; Sondeur; Underwater acoustics; Propagation; Signal processing; Sonar; Echosounder. Ano: 2001 URL: http://archimer.ifremer.fr/doc/00017/12790/9731.pdf Registros recuperados: 3 Primeira ... 1 ... Última

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