Results 171 to 180 of about 48,682 (230)
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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.
P. L. Feintuch, F. A. 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.
P. L. Feintuch, F. A. Reed
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Efficient Active Sonar Multitarget Tracking
OCEANS 2006 - Asia Pacific, 2006The active sonar environment presents a challenge for any tracking system. Multipath propagation and the fact that targets are, in general, extended objects mean that multiple measurements may be obtained for each target in the surveillance region. In addition, other objects and random scatterers introduce clutter measurements.
Darko Musicki +3 more
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Multi-waveform active sonar tracking
2007 International Waveform Diversity and Design Conference, 2007This paper extends the NURC distributed multi-hypothesis tracking technology to include Doppler sensitive (CW) processing. The assessment of the value-added of CW processing in automated undersea detection and tracking is ongoing.
Stefano Coraluppi +4 more
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Synthetic aperture active sonar imaging
[Proceedings] ICASSP-92: 1992 IEEE International Conference on Acoustics, Speech, and Signal Processing, 1992The main problems involved in synthetic aperture sonar imaging are medium instability, slow mapping rate, and platform motion. Proposed solutions to these problems are reviewed, and a new technique for synthetic aperture sonar imaging is presented which allows a fast mapping rate and improved motion compensation.
B.L. Douglas, H. Lee
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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.
S. Flatte +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.
S. Flatte +4 more
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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.
J. L. Stewart +2 more
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Shallow water active sonar issues
The Journal of the Acoustical Society of America, 1995The central questions in sonar system design concern the limits of coherent processing and are: What is the optimum frequency range and bandwidth?; How large of a receiving aperture is required?; What is the achievable detection range? These questions are determined by the propagation and scattering of sound.
William Carey, Peter G. Cable
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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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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.
P. Willett, J. Reinert, R. Lynch
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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 ...
L. Mozzone, S. Bongi, F. Filocca
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