FIELD: acoustics and applied hydroacoustics.
SUBSTANCE: proposed method that can be used for marine geological and geophysical investigations, search for sunk objects, and the like, and also in fish industry for searching and evaluating fish reserves includes generation of high-frequency pumping signals at frequencies ω1 and ω2, their amplification, and radiation into water medium, generation of differential-frequency wave Ω = ω1 - ω2 in water medium for locating investigated object, and reception of reflected differential-frequency wave Ω'; high-frequency pumping signals ω1 and ω2 are close to resonant frequency of air bubbles ω0 in water surface layer and are close to investigated object frequencies; in addition high-frequency pumping signal is generated at frequency ω3 close to second harmonic of air bubble resonant frequency ω0, amplified, and radiated into water medium; high-frequency signals are also received and amplified at combined frequencies ω3 ± Ω', then they are demodulated and filtered off to produce broadband signal of resonant frequency Ω' reflected from investigated objects.
EFFECT: provision for object detection and determination of its spatial coordinates in sea noise and intensive reverberation environment.
1 cl, 13 dwg
