Very High Frequency Volumetric Acoustic Array

The Navy has a need for a high-resolution, high-gain acoustic array that will allow them to make special acoustic measurements of full and model scale submarines. Volumetric arrays such as the High Gain array used on the Hayes for NSWC-CD source localization and the Twisted Bi-Cone array developed for SEAFAC have been used in the past, but are limited in terms of sensitivity, directivity, noise floor, and detection frequencies. Further, they are problematic in terms of physical construction; it is difficult or impossible to pack hydrophones densely enough to achieve the solicitation requirements. In this proposal alternate acoustic array configurations are discussed. Potential solutions are considered, including a planar or near-planar circular array comprising linearly tapered lines of hydrophones. Such a solution allows high gain and high-resolution, while greatly minimizing the quantity of hydrophones in comparison to a cylindrically symmetrical volumetric array. The proposal discusses tools at the offerer"s disposal that will facilitate array design and enable accurate modeling of proposed designs to verify specification compliance. Also discussed are various design challenges such as the physical construction of the array, signal conditioning, and data throughput and storage constraints.