Results 1 - 10 of 56

ElSharkawi, ″Environmentally Adaptive Sonar Control in a Tactical

by Warren L. J. Fox, Megan U. Hazen, Chris, J. Eggen, Robert J. Marks, Ii, Mohamed A. El-sharkawi - Impact of Environmental Variability on Acoustic Predictions and Sonar Performance , 2002
"... Automatic environmentally adaptive sonar control in littoral regions characterized by high spatial/temporal acoustic variability is an important operational need. An acoustic model-based sonar conroller requires an accurate model of how the sonar would perform in the current environment while in any ..."
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Automatic environmentally adaptive sonar control in littoral regions characterized by high spatial/temporal acoustic variability is an important operational need. An acoustic model-based sonar conroller requires an accurate model of how the sonar would perform in the current environment while

Sonar Image Segmentation Using an Unsupervised Hierarchical MRF Model

by Max Mignotte, Christophe Collet, Patrick Perez, Patrick Bouthemy - IEEE Trans. Image Processing , 1998
"... This paper is concerned with hierarchical Markov Random Field (MRF) models and their application to sonar image segmentation. We present an original hierarchical segmentation procedure devoted to images given by a high resolution sonar. The sonar image is segmented into two kinds of regions: shadow ..."
Abstract - Cited by 63 (10 self) - Add to MetaCart
This paper is concerned with hierarchical Markov Random Field (MRF) models and their application to sonar image segmentation. We present an original hierarchical segmentation procedure devoted to images given by a high resolution sonar. The sonar image is segmented into two kinds of regions: shadow

DETERMINATION OF THE TRANSDUCER VELOCITIES IN A SONAR ARRAY USING DIGITAL ACOUSTICAL HOLOGRAPHY

by C. Audoly
"... Résumé: Pour déterminer expérimentalement la vitesse vibratoire de trans-ducteurs dans une antenne d'émission, on propose une méthode d'holographie numérique utilisant un modèle théorique de l'antenne basé sur l'équation intégrale de Helmholtz. La méthode a l'avantage de ne ..."
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, on peut également reconstruire le champ de pression sur la surface de l'antenne et la directivité en champ lointain. Abstract: A digital holography method, based on a Helmholtz integral equation model of a sonar array, is proposed to determine experimentally the velocities of the transducers

European Conference on Underwater Acoustics MODEL BASED CLASSIFICATION OF MINE-LIKE OBJECTS IN SIDESCAN SONAR USING THE HIGHLIGHT

by unknown authors
"... Proceedings of the 11 ..."
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Proceedings of the 11

Real-Time 3D Sonar Modeling And Visualization

by Timothy M. Holliday , 1998
"... Virtual world simulations are realistic when each individual component is simulated in a manner that reflects reality. For an underwater virtual world that simulates acoustic detection, a physically based sonar propagation model is required if ranges in excess of tens of meters are expected. This th ..."
Abstract - Cited by 1 (0 self) - Add to MetaCart
Virtual world simulations are realistic when each individual component is simulated in a manner that reflects reality. For an underwater virtual world that simulates acoustic detection, a physically based sonar propagation model is required if ranges in excess of tens of meters are expected

Three-class Markovian segmentation of high resolution sonar images

by M. Mignotte, C. Collet - Comput. Vis. Image Understand , 1999
"... This paper presents an original method for analyzing, in an unsupervised way, images supplied by high resolution sonar. We aim at segmenting the sonar image into three kinds of regions: echo areas (due to the reflection of the acoustic wave on the object), shadow areas (corresponding to a lack of ac ..."
Abstract - Cited by 24 (7 self) - Add to MetaCart
This paper presents an original method for analyzing, in an unsupervised way, images supplied by high resolution sonar. We aim at segmenting the sonar image into three kinds of regions: echo areas (due to the reflection of the acoustic wave on the object), shadow areas (corresponding to a lack

Stylized Volume Visualization of Streamed Sonar Data

by Ruben Patel, Helwig Hauser, Ivanko Viola
"... Figure 1: Visualization of a large fish school of sand eel floating above the sea bottom reconstructed live from a series of 2D slices. The temporal outline color-encodes the temporal dimension of the volume visualization. Current visualization technology implemented in the software for 2D sonars us ..."
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integrated a low frequency illumination model which enhances the depth perception of noisy acoustic measure-ments. While we visualize the 2D data and time as 3D volumes, the temporal dimension is not intuitively communicated. Therefore, we introduce a concept of temporal outlines. Our system is a result

Bayesian Inference And Optimization Strategies For Some Detection And Classification Problems In Sonar Imagery

by M. Mignotte, C. Collet, P. Perez, P. Bouthemy , 1999
"... In this paper, we investigate the use of the Bayesian inference for some detection and classification problems of great importance in sonar imagery. More precisely this paper is concerned with the segmentation of sonar image, the classification of object lying on the sea-bottom and the classificatio ..."
Abstract - Cited by 6 (5 self) - Add to MetaCart
-bottom and the classification of sea-floor. These aforementioned classification tasks are based on the identification of the detected cast shadows which correspond to a lack of acoustic reverberation behind the different natural or man-made objects lying on the sea-floor. The adopted Bayesian approach allows to model

Bayesian acoustic prediction assimilating oceanographic and acoustically inverted data

by Nelson E. Martins, Sérgio M. Jesus - J. Mar. Syst , 2009
"... The prediction of the acoustic field evolution on a day to week frame, in a given oceanic area, is an important issue in sonar performance modeling. It relies pri-marily on acoustic propagation models, which convert water column and geomet-ric/geoacoustic parameters to ‘instantaneous ’ acoustic fiel ..."
Abstract - Cited by 3 (0 self) - Add to MetaCart
The prediction of the acoustic field evolution on a day to week frame, in a given oceanic area, is an important issue in sonar performance modeling. It relies pri-marily on acoustic propagation models, which convert water column and geomet-ric/geoacoustic parameters to ‘instantaneous ’ acoustic

Modelling three-dimensional directivity of sound scattering by Antarctic krill: progress towards biomass estimation using multibeam sonar

by George R Cutter , Josiah S Renfree , Martin J Cox , Andrew S Brierley , David A Demer Cutter , Renfree G R , J S Cox , M J Brierley , A S , Demer , D A , G R Cutter , J S Renfree , D A Demer , A M J S Cox , Brierley - ICES Journal of Marine Science , 2009
"... Target strength (TS) estimation is a principal source of uncertainty in acoustic surveys of Antarctic krill (Euphausia superba). Although TS is strongly dependent on krill orientation, there is a paucity of information in this regard. This paper considers the potential for narrow-bandwidth, multibe ..."
Abstract - Cited by 1 (0 self) - Add to MetaCart
-bandwidth, multibeam-echosounder (MBE) data to be used for estimating the orientations of krill beneath survey vessels. First, software was developed to predict MBE measurements of the directivity patterns of acoustic scattering from individual or aggregated krill in any orientation. Based on the distorted-wave, Born
Results 1 - 10 of 56