EAI designed, manufactured, and installed a complete Extended Low-Frequency Projector System (ELFPS)for the Naval Air Warfare Center consisting of a towed sound source, electro-mechanical tow cable, winch, mechanical handling system, power amplifier, and system monitors. The sound source produced a SL in excess of 160 dB re 1 microPascal at 1 meter from 10 Hz to 10 kHz. The towed sound source consisted of two projectors: a low-frequency moving coil projector and a higher frequency piezoelectric ceramic projector. A low-noise towed hydrophone was provided to monitor the radiated waveform.
The handling system for the towfish is capable of deployment and recovery in conditions up to Sea State 4 with the vessel underway. The complete system was field proven for operation to depths of 150 meters and speeds up to 10 kts.
| ELFPS Specifications | |
| Frequency Range | 10 Hz to 10 kHz |
| Source Level | 160 dB re 1 µPa @ 1 meter |
| Towfish Weight in Air | 750 lbs |
| Towfish Weight in Water | 225 lbs |
| Maximum Towing Speed | 10 knots |
| Operating Depth | 10 to 150 meters |
| Survival Depth | 500 meters with operational recovery |
| Compensation | Passive Bladder / Active Electro-Pneumatic |
Engineering Acoustics, Inc.