Description:
<jats:p>A one-watt sound source covering the frequency range from 1 to 10 Hz is under development. The source consists of a scoop towed 100 m beneath a ship feeding a modulated flow against a free piston backed by a compliant chamber. A constant sound-pressure output is obtained as the frequency is varied above the piston-compliant chamber resonant frequency. Fluidic circuit techniques are used to modulate the water jet that drives the free piston which produces the sound-source volume velocity. Low power electric signals are fed down the tow cable to control frequency and time modulation of the sound source. Ship speed determines the sound-pressure level.</jats:p>