PROJECT ARTEMIS ACOUSTIC SOURCE SUMMARY REPORT
NAVAL RESEARCH LAB WASHINGTON DC
Pagination or Media Count:
A directional 400-Hz source was developed for the Navy research program on undersea surveillance. The source can be operated over a 100-Hz frequency band from 350 to 450 Hz with a maximum available source level of 147 dB versus 1 dyne per square centimeter at 1 yard dB1 dynecm squared at 1 yd . The system is installed in a converted T-2 class A-2 tanker, the major modification being a well cut through the main deck and keel approximately at midship through which the transducer array is lowered to operating depth. The system includes winches and cable-handling machinery for lowering the approximately 800,000 pound transducer array to a 1200-foot depth. Interaction between transducer elements in the multielement array was a major problem in the system development. Although the effect of interaction was reduced, it was not completely overcome. The principal effect of the interaction was to cause excessive fatigue in transducer elements, necessitating reduction of input power to prevent transducer failure. A modified version of the element was developed which can withstand the larger displacement associated with interaction. If this element were used in the array, it is anticipated that a source level of approximately 156 dB could be obtained. This assumes that the pressure-release system required to suppress the back radiation of the array could be modified to withstand the higher acoustic intensity.
- Acoustic Detection and Detectors