Results 141 to 150 of about 1,058 (187)

Developments in sonar and array technologies

2011 IEEE Symposium on Underwater Technology and Workshop on Scientific Use of Submarine Cables and Related Technologies, 2011
Sonar and Array Technologies have been developed over more than 100 years. This paper will give an exposition of this development with emphasis on the most recent one. However, tracks to earlier sonar types will be illuminated. Demands to sonar and arrays will be discussed, and an exposition will be given of the state-of-the-art in single-beam and ...
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Acoustic decoupler for a sonar array

The Journal of the Acoustical Society of America, 1992
An inner decoupler for a sonar array including a linear array of hydrophones and consisting of an alternating multi-layer configuration of acoustic compliance elements in the form of acoustic baffles and acoustic non-compliance elements in the form of water or other acoustic mass-like element located between the hydrophones and the outer surface of a ...
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An optimal sonar array for target localization and classification

Proceedings of the 1994 IEEE International Conference on Robotics and Automation, 2002
A novel sonar array for mobile robots is presented with applications to localization and mapping of indoor environments. The ultrasonic sensor localizes and classifies multiple targets in two dimensions to ranges of up to 8 meters. By accounting for effects of temperature and humidity, the system is accurate to within 1 mm and 6.1 degrees in still air.
Lindsay Kleeman, Roman Kuc
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Shape and doppler correction for a towed sonar array

Oceans '04 MTS/IEEE Techno-Ocean '04 (IEEE Cat. No.04CH37600), 2005
Anti Submarine Warfare (ASW) is more and more focused toward shallow water environments. Many complications have come up for ASW sonar performance as a result of this. The problem that is tackled in this article is the performance loss due to the shape and motion of the sonar during a maneuver. Standard beamforming in towed sonar arrays is based on the
Groen, J., Beerens, S.P., Doisy, Y.
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Disappearing baffle for sonar arrays

The Journal of the Acoustical Society of America, 1989
A selectively transparent baffle means for controlling beam pattern dispel or direction, further comprising a plurality of parallel, vertically oriented, compliant tubes each of which attach to one of two header tubes at one end while the opposite ends are open to sea pressure. The headers provide air fill or vent.
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Optical Processing for Sonar Arrays

1999
Abstract : We present an adaptation of the BEAMTAP (Broadband and Efficient Adaptive Method for True-time-delay Array Processing) algorithm, previously developed for wideband phased array radars, to lower bandwidth applications such as sonar. This system utilizes the emerging time or wavelength multiplexed optical hydrophone sensors and processes the ...
Lloyd Griffiths, Dana Anderson, Kelvin Wagner   +2 more
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Optimized aberration correction for sonar arrays

Global Oceans 2020: Singapore – U.S. Gulf Coast, 2020
In this paper a method using simulated annealing is applied to the problem of array pattern synthesis subject to aberrations. For linear arrays an optimal suppression of the maximum sidelobe level can be achieved using a Dolph-Chebyshev window. However, the sensitivity of this window to position and phase aberrations means it has practical limitations ...
Jan Egil Kirkebo, Andreas Austeng
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Matched array processing for wideband passive sonar

ICASSP '81. IEEE International Conference on Acoustics, Speech, and Signal Processing, 2005
The Matched Array Processor (MAP) is quadratic adaptive matrix filter designed to optimize detection and bearing estimation of a desired wideband target signature in the presence of interferences. It is made adaptive in the spatial domain to remove interferences entering through the beam sidelobes and it is spectrally matched to the signal of interest.
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Phased array Doppler sonar transducer

The Journal of the Acoustical Society of America, 1987
A plurality of piezoelectric or magnetostrictive rectangular planar staves are held in side-by-side relation in a laminate assembly including insulative spacers. The widthwise polarity of adjacent pairs of the staves are inverted relative to each other.
Robert L. Simmons, Clifton M. Wyant
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Receiver array technology for sonar

1985
In sonar, we are concerned with the detection of targets against a background of unwanted signals. These unwanted signals may be noise in several forms, or reverberation. The task of the receiving system designer is to ensure an optimal system response to the wanted signal and minimal response to the unwanted signal.
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