SYSTEM FOR PROTECTING SHIPS FROM UNDERWATER DRONES Russian patent published in 2024 - IPC G01S3/38 G01S13/86 G01S15/87 

FIELD: sonar; radar.

SUBSTANCE: invention relates to sonar and radar and can be used to detect, estimate coordinates and destroy marine unmanned aerial vehicles (UAV). Disclosed system for protecting ships from underwater drones includes a system of sonars and radars with a circular field of view installed on board the ship, which provide monitoring of their appearance and evaluation of coordinates of underwater drones in the underwater and surface position. Complex of sonars includes a pair of transceiving acoustic phased antenna arrays with electronic azimuth scanning installed along the ship board below the waterline, the transmitting array of which is connected to a pulse generator of acoustic oscillations, and the receiving room is connected to two phase detectors operating with an interval of one emission period of the transmitter. Output of the phase detectors includes band-pass filters of Doppler frequency signals of a moving target, which are connected through a mutual correlator to a threshold device for recognizing the moment when the target appears. Complex of radars includes narrow-band radars with switching of the polarization plane of the emitted waves, which are installed above the upper deck of the ship, each of which provides scanning along the azimuth of its scanning sector. Two orthogonal dipoles connected to a transmitter are placed at the focus of the mirror of the radar antennae. Receiving outputs of the circulators are connected through an amplitude detector to a second switch operating through one scanning period of the scanning sector, connected to two band-pass filters, tuned to the switching frequency of the polarization plane, outputs of which are connected through phase detectors to a microcontroller, which calculates the cross-correlation coefficient of Doppler frequency signals periodically arriving after one scanning period of radars of the corresponding scanning sector. Target detection and recognition is carried out by calculating the cross-correlation coefficient of Doppler frequency signals of the moving target, received after one period of scanning space, and comparing the calculated cross-correlation coefficient with a given threshold.

EFFECT: high reliability of detecting and identifying a low-visibility target in the form of a UAV by decorrelation of interference caused by sea disturbance and cavitation of water in the wake jets of the ship and the UAV.

2 cl, 6 dwg