High Fidelity, Low Power, Omnidirecddtional Hydrophone

There is a need to advance the state of the art low power, portable autonomous underwater hydrophones for recording fish spawning calls and other marine acoustics. Affordable and reliable autonomous underwater vehicle (AUV) mountable hydrophones that can detect such signals in the presence of AUV motor noise are required. A system that includes software to automatically determine fish size, type, and location would be extremely useful for monitoring fish populations, and for helping to understand the effects of climatic and environmental changes. Current underwater monitoring systems are presently prohibitively expensive, and have long-term reliability issues because the electronic acoustic sensors, and their associated metallic conduits, are intrinsically prone to degradation from salt water. In Phase I, Intelligent Optical Systems, Inc. (IOS) demonstrated the feasibility of developing a fiber optic-based hydrophone sensor head consuming low power, and offering a high signal-to-noise ratio in the frequency range desired for monitoring marine acoustics. In Phase II, IOS proposes to design, develop, and test an AUV-mountable, low power, batter operated high fidelity, omnidirectional hydrophone that will provide high sensitivity and reliability at depths down to ~1000m, and high SNR in the frequency range desired for fish acoustic monitoring.