Results 171 to 180 of about 594,002 (213)

Handbook of sonar transducer passive materials

The Journal of the Acoustical Society of America, 1981
Some aspects of the engineering applications of elastomeric materials in sonar transducers are discussed. A sonar materials handbook being published as NRL Memorandum Report 4311 is also briefly reviewed.
R. N. Capps, F. J. Weber
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The passive sonar equation - effects of additive interference

ICASSP '76. IEEE International Conference on Acoustics, Speech, and Signal Processing, 2005
An equation representing the statistical variability of SONAR parameters is cast into a form allowing computation of the effects of additive interference. The technique may be applicable in cases where electronics noise, structural (platform) noise, or flow noise contribute to degradation of detection performance. The passive SONAR equation is factored
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Passive Sonar Signal Processing

1981
An overview of applied research in passive sonar signal processing estimation techniques for naval systems is presented. The naval problem that motivates this work is the source state estimation problem. A discussion of this problem in terms of estimating the position of a moving acoustic source is presented.
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Optimum Design of Broadband Passive Sonar

IEEE Journal of Oceanic Engineering, 2016
In this paper, a new design principle is proposed for the frontend-hardware (FEHW) chain of broadband passive sonars. This principle embraces the ultimate purpose of broadband passive sonars, which is to maximize the detection of passive targets. FEHW chains were conventionally designed as noise whiteners to guarantee the data bit dynamic range in ...
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An optimum broadband detector for passive sonar

2012 Annual IEEE India Conference (INDICON), 2012
In low SNR applications like passive surveillance sonar, an optimum detector which maximizes the output SNR is of prime importance. This paper presents a novel practical implementation scheme for an optimum (in Neyman Pearson sense) broadband detector for passive sonar, which includes a post beamformer filter named Eckart filter whose goal is to ...
G.R Anupama, K.E Nissar, Sarath Gopi, V.P Felix   +3 more
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Panoramic audio device for passive sonar

The Journal of the Acoustical Society of America, 2005
The invention concerns panoramic audio devices to process the impulsive signals received by passive sonars. It consists in isolating, in each beam, impulsive signals in the frequency and time domains and then filtering them according to the characteristics of the human ear.
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Passive Sonar Detection in the Presence of Interference

The Journal of the Acoustical Society of America, 1968
The paper deals with the detection of a passive sonar target in the presence of ambient noise and a plane-wave interference. Target signal, interference, and ambient noise are assumed to be Gaussian random processes, the ambient noise being statistically independent from hydrophone to hydrophone.
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Target classification in a passive sonar-an expert system approach

International Conference on Acoustics, Speech, and Signal Processing, 2002
A study of passive classification of underwater targets is made. A set of features pertaining to four different classes of vessels are identified, and methods of extraction of these features from the data are outlined. An expert system using Turbo PROLOG is developed for classifying the vessels. The confidence level of the classifier is analyzed. >
R. Rajagopal 0001, B. Sankaranarayanan, P. Ramakrishna Rao   +2 more
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A neural network for target classification using passive sonar

Proceedings of the conference on Analysis of neural network applications, 1991
This concerns the design, tratilng, test and evaluation of a feed-forward neural network for classifying acoustic signals emitted by ships in transit by an omnidirectional hydrophore. Relatively noisy surface ships, moving rapidly at medium to long range, emit signals which superficially resemble those of quieter submarines, moving more slowly and ...
Robert H. Baran, James P. Coughlin
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Application of multitaper methods to passive sonar

The Journal of the Acoustical Society of America, 2007
While the multitaper spectral estimation method [Thomson, Proc. IEEE 70, 1055–1096 (1982)] is used extensively in time series analysis, it has received much less attention in the array processing literature. The multitaper approach reduces the variance of power estimates by averaging windowed Fourier transforms of the data obtained using a set of ...
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