Results 261 to 270 of about 4,113,395 (325)
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LPI waveforms for active sonar?
2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720), 2004The idea of a low probability of intercept (LPI) waveform is that its form is chaotic. It can of course be recalled by the transmitter (platform), and matched to what is received; but to the target it appears only as noise, and consequently the robust target receiver can only detect a rise in energy.
J. M. Reinert +2 more
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2004
Abstract : JASON was tasked by the ONR to study the recent spate of whale-beaching events which have been linked to sonar exercises. The initial goal of the study was to use the current level of understanding of these events to recommend modifications of the sonar waveform as a mitigation strategy.
C. Callan +4 more
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Abstract : JASON was tasked by the ONR to study the recent spate of whale-beaching events which have been linked to sonar exercises. The initial goal of the study was to use the current level of understanding of these events to recommend modifications of the sonar waveform as a mitigation strategy.
C. Callan +4 more
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A PMHT algorithm for active sonar
SPIE Proceedings, 2004ABSTRACT The Probabilistic Multi-Hypothesis Tracking (PMHT) algori thm proposed by Streit and Luginbuhl in 1995 is adapted here for use in active sonar applications. PMHT is a batch technique that uses the Expectation-Maximization (EM) algorithm to obtain MAP estimates of the sequence of target states. Probabilistic Multi-Hypothesis Tracking for Active
Christian G. Hempel, Sheri L. Doran
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Journal of the Acoustical Society of America, 2020
High-order time lacunarity (HOT-Lac) is an effective feature for characterizing active sonar echographs of harbor environments. However, it involves high computational complexity of loop summations.
Shuang Zhao +5 more
semanticscholar +1 more source
High-order time lacunarity (HOT-Lac) is an effective feature for characterizing active sonar echographs of harbor environments. However, it involves high computational complexity of loop summations.
Shuang Zhao +5 more
semanticscholar +1 more source
The Journal of the Acoustical Society of America, 2001
The decomposition of the time reversal operator (DORT) is a single frequency method of spatially isolating scatterers with a multiple-source/multiple-receiver system [C. Prada et al., J. Acoust. Soc. Am. 99, 2067–2076 (1996)]. The application of the DORT technique to a broadband sonar system is explained by showing its relationship to the sonar ...
Charles F. Gaumond, David M. Fromm
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The decomposition of the time reversal operator (DORT) is a single frequency method of spatially isolating scatterers with a multiple-source/multiple-receiver system [C. Prada et al., J. Acoust. Soc. Am. 99, 2067–2076 (1996)]. The application of the DORT technique to a broadband sonar system is explained by showing its relationship to the sonar ...
Charles F. Gaumond, David M. Fromm
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Diversity in multistatic active sonar
Oceans '99. MTS/IEEE. Riding the Crest into the 21st Century. Conference and Exhibition. Conference Proceedings (IEEE Cat. No.99CH37008), 2003A multistatic network of autonomous active transmitters and receivers, such as deployable underwater surveillance systems, often provides multiple contacts of the same target. The present paper examines the effects of receiver diversity ("spatial diversity") on a multistatic system, where three independent, spatially separated sonar receivers detect ...
F. Filocca, L. Mozzone, S. Bongi
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Bayesian occupancy grid for active sonar detection and localization of moving targets
Global Oceans 2020: Singapore – U.S. Gulf Coast, 2020Active sonar performance is highly dependent on the surrounding environment. Conventional detection algorithms apply thresholds to acoustic data passed through a normalizer in order to detect targets.
K. Hjelmervik +5 more
semanticscholar +1 more source
Survey of active sonar simulations
The Journal of the Acoustical Society of America, 2004In lieu of well-characterized measured data sets, time series simulations are often employed for testing active sonar systems. This paper reviews the simulation techniques and models that are being employed today and discusses some of the issues of fidelity that may arise with regard to range dependence, bistatic geometries, reverberation statistics ...
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The Journal of the Acoustical Society of America, 1991
A channel adaptive active sonar is disclosed, wherein the sonar transmit waveform is adaptively selected in accordance with the measured sonar channel scattering function to reduce the response of the sonar to unwanted reverberation while preserving the response to signal returns.
Paul L. Feintuch, F. Reed
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A channel adaptive active sonar is disclosed, wherein the sonar transmit waveform is adaptively selected in accordance with the measured sonar channel scattering function to reduce the response of the sonar to unwanted reverberation while preserving the response to signal returns.
Paul L. Feintuch, F. Reed
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Active sonar clutter and auralization
The Journal of the Acoustical Society of America, 2008Target-like false alarms generically termed clutter are the primary hindrance to active sonar in shallow water operational areas. Clutter can arise from a myriad of sources with geologic, biologic and anthropogenic origin. The clutter-source echoes are often determined by automatic signal processing to be target-like and therefore potentially of ...
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