Multistatic Acoustic Source for Unmanned Underwater Vehicles (UUV)

Period of Performance: 05/22/2000 - 11/22/2000


Phase 1 SBIR

Recipient Firm

Image Acoustics, Inc.
56 Margin Street Array
Cohasset, MA 02025
Principal Investigator


A low frequency underwater acoustic source for Unmanned Underwater Vehicles (UUV) will be developed. The transducer will operate in the 300 Hz to 500 Hz spectrum with an acoustic source level of at least 205 dB /1uPa @ 1m. The proposed innovative transducer design will be based on the X-spring design (U. S. Patent 4,845,688 "Electromechanical Transduction Apparatus,"). The new X-spring transducer element configuration proposed uses a large 33 mode ring which drives two concave cone shaped shells which, in turn, amplify the motion translated to two symmetrical pistons. The design allows an increase in radiating area and a magnified motion resulting in a larger volume velocity than could be achieved from a ring alone. Also, the radiation load is magnified yielding a low Q and high mechanical efficiency even at low frequencies. Although a single transducer should be capable of achieving the desired acoustic source level, we present a directional capability scheme where an improved directivity index can be achieved reducing the power needed for the desired level. A UUV transducer for multi-static sonar applications will be developed. The ring driven X-spring approach should provide a scalable approach applicable to current and future underwater acoustic systems. The technology should provide improvement for low frequency sonar systems, and for oceanographic and possibly tomography applications.