Accession Number : ADD018105

Title :   Method and System for Sensing with an Active Acoustic Array.

Descriptive Note : Patent, Filed 28 Jun 93, patented 9 Jul 96,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Yang, Tsih C

Report Date : 09 Jul 1996

Pagination or Media Count : 7

Abstract : A method and system provide for the sensing of objects under water where the acoustic energy is suitably focused or directed so that reverberation returns are minimized. A vertical source array of adjustable acoustic sources is located in the water body, with each acoustic source producing a separate acoustic pulse or continuous wave controlled by a control device. The control device controls a phase and amplitude of the separate acoustic pulses such that a waveform (combined acoustic pulse) with selective nodes adjustable to a desired depth is emitted. A calibration device is also located at a distance from the source array for calibrating the separate acoustic pulses or continuous wave so that the source array emits a desired waveform. The calibration device includes a checking device for determining whether the emitted waveform conforms to the desired waveform and for calculating a deviation of the emitted waveform from the desired waveform. The calibration device also includes a feedback device for feeding deviation information back to the control device which further controls each acoustic source in accordance with the deviation information back to the control device which together controls each acoustic source in accordance with the deviation information so that the desired waveform is produced. The control device controls the sources to generate continuous waves and/or combined pulses focused to a desired depth domain or a desired range-and-depth cell in the water body.

Descriptors :   *ACOUSTIC ARRAYS, *SONAR SOUND ANALYZERS, *PATENTS, CONTROL SYSTEMS, CONTINUOUS WAVES, NODES, FEEDBACK, ACOUSTIC SIGNALS, CALIBRATION, REVERBERATION, SOUND GENERATORS

Subject Categories : Acoustic Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE