Highly directive array aperture

摘要

An apparatus and method is provided that utilizes sonar array discontinuities for increasing the directivity gain of a sonar system by increasing the ratio of trace wavelengths (replicated) to the length of a fixed array aperture. Impedance discontinuities, or blocking masses, are embedded in a matrix material of fixed length to create Bragg scattered longitudinal displacements of a wavelength. The longitudinal displacements are induced by an incident acoustic plane wave. This creates longitudinal replicas of the displacements, shifted in wave number, creating a scaled acoustic trace wavelength. The replicated trace wavelength is sampled and resolved, thereby increasing the directivity gain of a sonar system.

主权项

1. A method for making a sonar array with high directivity for receiving an acoustic wave in an operating environment comprising:
providing a matrix material in which said acoustic wave induces a longitudinal wave along a length of the array; positioning a plurality of blocking members in said matrix material operable to interfere with said longitudinal wave to create smaller replica waves between said blocking members; positioning a plurality of sensors in said matrix material between said blocking members operable to detect particle motion of said replica waves between said blocking members; coupling a signal processor to said plurality of sensors; and utilizing said signal processor and said detected particle motion to determine an incident angle of the acoustic wave.