ONR HLF-3 Source Operations for MIZEX 84.
HYDROACOUSTICS INC ROCHESTER NY
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This final report briefly describes the preparation, system checkout, and tow operations of the ONR HLF-3 for the MIZEX 84 experiment in the FRAM STRAIT. The HLF-3 low frequency acoustic projector was towed during June, 1984 from the U.S.N.S. LYNCH in the Greenland Sea. The projector was towed at speeds up to nine knots and at depths between 100 and 110 meters during two tow periods totalling 291 hours of source operation. The HLF-3 transmitted single tones, multiple tones, and noise between 25 and 275 Hz at levels to 194 dB re 1 microPa at 1m. The major components of the HLF-3 sound source system are the sound source mounted in a tow body, a faired tow cable, a topside motor starter 440 VAC, 3-PHASE, a FM telemetry system, and a topside monitor-controller. The sound source is a short cylinder, 47 inches in diameter and 20 inches long. Two center-driven, steel alloy flexural disk radiators are mounted back-to-back on a cylindrical aluminum housing. The housing is a spoke stiffened 6061 aluminum alloy ring which serves to mount the flexural disk radiators and contains all the submersible components of the system. The drive piston assembly, hydroacoustic circuits, five horsepower hydraulic power supply, and various electronic sensors and components are contained within the housing.
- Acoustic Detection and Detectors