Results 251 to 260 of about 4,113,395 (325)
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A Theory of Active Sonar Detection
Proceedings of the IRE, 1959The results of a theory of echo detection developed for radar are extended to sonar for the case of narrow-banid transmitted signals. The exposition specifically omits discussion of the decision problem and the statistical nature of the whole process of detection.
E. C. Westerfield, J. L. Stewart
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Application of DORT to active sonar
Oceans '04 MTS/IEEE Techno-Ocean '04 (IEEE Cat. No.04CH37600), 2005Active sonar in shallow water is often reverberation-limited and the detectability is often limited by the presence of too many false alarms. The problem of improving detection, and classification, in shallow water is being worked on in several different ways. The time reversal operator decomposition (DORT) is a technique that has recently been applied
Joseph F. Lingevitch +6 more
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Demonstration of the invariance principle for active sonar
The Journal of the Acoustical Society of America, 2008Active sonar systems can provide good target detection potential but are limited in shallow water environments by the high level of reverberation produced by the interaction between the acoustic signal and the ocean bottom. The nature of the reverberation is highly variable and depends critically on the ocean and seabed properties, which are typically ...
Lisa M. Zurk +2 more
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Active sonar and the marine environment
AIP Conference Proceedings, 2004A study of the effects of active sonar transmissions on fish and marine mammals in Norwegian waters has been launched following the ordering of new frigates by the Royal Norwegian Navy (RNoN). The frigates will be equipped with active sonars operating at lower frequencies than those of the sonars currently in operation in the RNoN.
Erik M. Sevaldsen, Petter H. Kvadsheim
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Journal of the Acoustical Society of America, 2020
This paper presents a feature for detecting potential targets from high level littoral clutters in active sonar echographs. Based on lacunarity, which describes the image texture statistics, an extension to the time domain is made in order to measure the
Shuang Zhao +3 more
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This paper presents a feature for detecting potential targets from high level littoral clutters in active sonar echographs. Based on lacunarity, which describes the image texture statistics, an extension to the time domain is made in order to measure the
Shuang Zhao +3 more
semanticscholar +1 more source
Optimum Frequencies for Active Sonar
The Journal of the Acoustical Society of America, 1960The method of determination of the optimum frequencies for active sonar without knowledge of the absolute values of the sonar set parameters, but only of their frequency dependence, appears to have been originated by J. W. Horton in about 1945 and is to be found in his recent text [J. W.
James L. Stewart +2 more
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IEEE Journal of Oceanic Engineering
Anomaly detection is suitable for active sonar classification due to its ability to handle the challenges posed by small imbalanced data sets. Recently, a modified anomaly detection approach called bisphere anomaly detection (BiSAD) has been developed ...
Geunhwan Kim, Youngmin Choo
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Anomaly detection is suitable for active sonar classification due to its ability to handle the challenges posed by small imbalanced data sets. Recently, a modified anomaly detection approach called bisphere anomaly detection (BiSAD) has been developed ...
Geunhwan Kim, Youngmin Choo
semanticscholar +1 more source
Improved Active Sonar Tracking in Clutter Using Integrated Feature Data
IEEE Journal of Oceanic Engineering, 2020Target tracking has traditionally focused on the use of kinematic information, such as bearing, range, position, or speed. In some cases, it is possible to extract additional target information that may be useful in the maintenance of reliable tracks, or
G. Mellema
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Waveguide invariance for active sonar.
The Journal of the Acoustical Society of America, 2009Active sonar signal processing in shallow water has proven to be a challenging problem due to the strong interaction of sound with the boundaries of the channel and the dependence on typically unknown environmental parameters. This has motivated research on properties of acoustic propagation that are not sensitive to those factors, such as the ...
Jorge E. Quijano, Lisa M. Zurk
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Unleashing the Power of Active Sonar
IEEE Pervasive Computing, 2017The authors explore various applications that can be enabled by transforming mobile devices into active sonar systems. Specifically, they show how to use microphones and speakers available on existing smartphones to monitor minute body movements such as breathing.
Shyamnath Gollakota +1 more
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