METHOD FOR DETECTION OF UNDERWATER SOURCE OF BROADBAND NOISE Russian patent published in 2019 - IPC G01S3/80 

FIELD: hydro acoustics.

SUBSTANCE: method for detecting an underwater source of broadband noise relates to hydroacoustics and can be used in systems for noise direction and underwater monitoring. Method includes receiving broadband source noise by a combined receiver comprising a sound pressure receiver and a three-component receiver of the vibrational velocity vector of the particles of the medium, wherein: generating, for a received signal, a set of frequency channels covering the entire observed frequency band; for each time fragment of the received signal: calculating in each frequency channel the horizontal angle of arrival of the acoustic energy flow and its intensity value; distributing energy flows of frequency channels on assigned equal to horizontal angular sectors of observation horizon; calculating for each angular sector value of sector intensity of energy flow; calculating a value of average sector intensity of energy flow and assigning it threshold value; selecting from angular sectors, energy flow sector power intensity of which exceeds threshold value; based on the processing results of a number of time fragments of the received signal, a sonogram of the time-angular arrival of the energy flux of the extracted sectors is formed, from which the dominant angular sector with the maximum value of the sector intensity of the energy flow is determined, and the time stability of the value of the latter is estimated; analysing the current sonogram data and deciding on the broadband noise source detection based on the level of the sector energy intensity exceeding the dominant angular sector of the threshold value, by the time stability of the level, as well as correspondence of temporal variability of orientation of dominant angular sector to expected dynamics of source motion, and on orientation of dominant sector on direction to source.

EFFECT: high noise-immunity of the receiving system and range of detection of a source of broadband noise based on directional properties of the flow of acoustic energy from it through spatial filtration of noise emission of the source and accumulation of the value of energy of the flow from the source at each frequency of the observed frequency range.

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