METHOD FOR DETERMINING THE COORDINATES OF A NOISE-EMITTING SEA TARGET Russian patent published in 2022 - IPC G01S15/00 

FIELD: acoustics.

SUBSTANCE: area of application: invention relates to the field of hydroacoustics, namely, to methods and apparatus for detecting sea targets by noise emission thereof; more specifically, to methods for determining the coordinates of the targets using correlation maxima in an autocorrelation function of target noise. Substance: in the method, by generation an exponential function for each correlation maximum (CM) from the combined two-dimensional array of KMs of the received signal, a combined autocorrelation function (ACF) of the received signal is generated by summing the values of exponential functions of all KMs for each time count separately; calculating the values of the signal to noise ratio (SNR) for each point in the area of possible target location at the output of the spatial channels of the tiers of the vertical fan of pattern characteristics (VVHN) of the sound-locating station (SLS) in three frequency bands (FB) for a single noise level of the target; calculating, for each point in the area, the energy structure of the signal and the intensities of each calculated KM in each VVHN tier in three FBs for a single noise level of the target; recording the KM intensities calculated in the FB corresponding to the frequency of the received signal in the two-dimensional array of calculated KMs; normalising the intensity value of each calculated KM for each point in the area using the maximum SNR value of the received signal and the calculated SNR value for the corresponding point, calculated in the FB corresponding to the frequency of the received signal and in the VVHN tier corresponding to the optimal reception tier; generating exponential functions for all calculated KMs for each point in the area; generating the calculated ACF for each point in the area by summing the values of function of all the calculated KMs in this point; resetting the values of ACF in the vicinity of the points in time wherein the values of KM intensities do not exceed the threshold value for detecting the KM in the SLS path ACF; calculating the correlation coefficient for each point in the area between the calculated ACF generated therefor and the combined ACF of the received signal, and determining the coordinates of the target by selecting the coordinates of the point of possible location of the target wherefor the highest value of the correlation coefficient was obtained.

EFFECT: ensured detection of sea targets.

1 cl, 1 dwg