METHOD OF DETECTING LOCAL OBJECT AGAINST BACKGROUND OF DISTRIBUTED INTERFERENCE IN BISTATIC SONAR Russian patent published in 2020 - IPC G01S15/42 G01S15/87 G01S7/539 

FIELD: hydro acoustics.

SUBSTANCE: invention relates to the field of hydroacoustics and can be used for construction of detection systems of local objects in conditions of distributed interferences of various origin. Method comprises emitting a complex probing signal, receiving an echo signal simultaneously by first and second multi-channel receiving paths, spatial receiving channels of which form a fan of static directional characteristics, set of time implementations in each receiving channel, determination in each receiving channel in each time realization of the first and second receiving paths of modules of mutually-covariance function of the received and emitted signals by means of inverse Fourier transform of convolution of spectrum of the received signal with complex conjugated spectrum of the emitted signal. Correlation of envelopes of time realizations of receiving channels of the first and second receiving paths, aimed at an angle and at a distance to an expected location of a detection object, based on calculation of maximum modulus of mutual covariance function between envelopes of received echo signals for each pair of selected receiving channels. Further, average value is determined by all maxima, all maxima of mutually-covariance functions are normalized to their average value, and decision on availability of local object is accepted in case of exceeding normalized maxima of mutually-covariance functions of level of specified threshold not more, than in N receiving channels, otherwise decision is made on detection of non-local object.

EFFECT: technical result is high noise immunity of bistatic sonar detecting local objects in conditions of intense reverberation interference and low level of echo signal with multi-field structure of detection object.

1 cl, 8 dwg