METHOD TO DETECT NOISY OBJECTS IN SHALLOW SEA Russian patent published in 2019 - IPC G01S15/04 

FIELD: hydro acoustics.

SUBSTANCE: invention relates to the field of hydroacoustics and can be used in noise control systems. Method includes receiving a noise signal by a combined receiver comprising a sound pressure receiver and a three-component pressure gradient vector receiver, frequency-time processing of the received signal, calculation in each frequency channel formed as a result of frequency-time processing of received noise signals, complex amplitudes of sound pressure, three components of the pressure gradient vector, three components of the oscillation speed vector, three components of the intensity vector in the local coordinate system associated with the combined receiver, for total process of signal plus interference and for interference separately, formation in each frequency channel of 8-channel static fan of directivity characteristics in horizontal plane, generating in each frequency channel of 2-channel static fan directional characteristics in a vertical plane, calculating a signal plus interference for the overall process and for separately taking 20 components, real and imaginary, an intensity vector in 10 spatial channels, calculating six quadratic components for the pressure gradient vector, five components for the intensity vector rotor and for the square of the sound pressure, centering and normalizing all 32 information parameters calculated for the total signal plus interference process, to the corresponding information parameters calculated for the interference, then maximum signal-to-noise ratio is calculated for one of 32 informative parameters, and decision is made on detection of maximum signal-to-noise ratio calculated for one of 32 informative parameters by comparison with threshold value of signal-to-noise ratio.

EFFECT: increase noise immunity and range of the receiving system at low frequencies in shallow sea conditions by using a receiving system that has directivity in shallow sea conditions at any arbitrarily low frequencies.

1 cl, 1 dwg