METHOD FOR DETECTING A LOCAL OBJECT AGAINST BACKGROUND OF DISTRIBUTED INTERFERENCE Russian patent published in 2022 - IPC G01S15/04 

FIELD: hydroacoustics.

SUBSTANCE: invention relates to the field of hydroacoustics and can be used to build systems for detecting local objects in conditions of distributed interference of various origins. In the method for detecting a local object against a background of distributed interference, a complex probing signal is emitted in the form of a sequential bundle of N identical complex elementary pulses. After receiving the echo signals, the spectrum of the envelope of the module of the mutual covariance function in each time realization corresponding to the duration of the elementary pulse is determined. The stored spectra of the current q-th realization are multiplied in pairs with the complex-conjugate spectrum (q-1) of the previous realization. The obtained (N-1) pairs of products of complex conjugate spectra of neighboring realizations are summarized. By calculating the inverse Fourier transform of the resulting sum, the correlation relationship between the implementations is determined and the maximum value of the modulus of the mutual covariance function is determined. All the maxima of the modules of the cross-covariance functions are normalized by a certain average value of the modules for the selected set of time implementations. If the normalized maximum of the cross-covariance function of the level of a given threshold is exceeded, a decision is made on the presence of a local object in the selected set of time implementations.

EFFECT: increase in the noise immunity of detecting local objects against the background of distributed interference by sonars that have a single-channel receive path.

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