Volumetric passive sonobuoy array of polyvinylidene fluoride (PVDF) wires

Reference#: P02277

There is a need to array designs and signal processing approaches to satisfy a number of requirements: (a) high-frequency passive sonar to mitigate clutter form shipping noise; (b)The sonar system should be easy to deploy and the number of array elements should be minimized to reduce data rate and processor demand; (c)To maximize the detection range of the system, a new design must feature a vertical aperture to exploit the ambient noise anisotrophy and; (d) In addition, the system must be inexpensive for use as expendable units for multiple uses such as adjuncts to ocean observatories deployable from air or surface platforms.

A sonar system for detecting underwater acoustic signals is provided herein, the sonar system comprising: (a) a plurality of hydrophone units capable of converting acoustic impulses to electrical signals, said hydrophone units being substantially vertically oriented when deployed in a body of water, and aid hydrophone units occupying at least some of the positions of an NxM horizontal array wherein N is the number of rows and M is the number of columns in the array; (b) means for applying a two-dimensional Chebychev mathematical weighting to the electrical signals from the individual hydrophone units such that each individual signal from each hydrophone unit is assigned a respective weighting number a numerical value is assigned to each individual signal corresponding to the strength of the electrical signal as adjusted by the respective weighting number; and (c) means for deploying said hydrophone units in the body of water. The sonar system advantageously reduces beam side lobes which cause confusion of the acoustic signals and hamper accurate detection and directional localization of target marine vessels. Moreover, microprocessor demand is minimized.

Patent Status: U.S. patent(s) 7675819 issued.

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