Method and system for detecting and distinguishing passive synthetic aperture target signal

Abstract

The present invention provides a method and a system for detecting and distinguishing a passive synthetic aperture target signal, wherein the method comprises the following steps: step 101) constructing a motion doppler receiving model for a target signal under motion of a towed array sonar; step 102) respectively performing cross correlation averaging on target signals which are received by a hydrophone at an overlapping part on spatial position according to a passive synthetic aperture sonar algorithm when the array performs two successive motions in a fixed time interval, and then performing frequency domain wave beam forming treatment on the target signals which are received by array elements at different time periods; step 103) performing energy integration on the output sub-frequency-bands after forming of the frequency domain wave beam for obtaining wave beam output of each time interval; step 104) performing phase estimation on time delay and spatial position movement according to the doppler receiving model, and acquiring a phase correction factor according to the phase estimation; and step 105) compensating the wave beam output through each phase correction factor of time interval, and performing cross combined accumulation on the compensated wave beam output and realizing detection on the target through a time orientation process map.

Description

technical field [0001] The invention relates to an underwater acoustic passive sonar signal detection method and an algorithm for detecting and distinguishing target signals by passive synthetic aperture sonar (Passive Synthetic Aperture Sonar, PSAS) technology, in particular to a moving non-overlapping aperture towed linear array Passive synthetic aperture signal detection method and system. Background technique [0002] In recent years, the detection of low-noise targets by passive sonar systems has become more and more important and difficult. With the emergence and rapid development of quiet targets, its detection ability has been seriously challenged. Throughout the history of sonar development, high resolution and high gain have always been the goals pursued by the sonar field. However, due to the limitation of stability and maneuverability in the towing process, it is unrealistic to increase the length of the array to too large an order. The passive synthetic apertur...

AI Technical Summary

Problems solved by technology

Due to the array movement deviation caused by the disturbance of the medium and the path in the actual underwater complex environment, the phase correction compensation of the conventional passive synthetic aperture sonar algorithm is at two consecutive positions with a fixed interval, and the front and rear apertures of the array elements do not completely coincide, so that the phase estimation factor Errors or even errors occur, that is, there are overlapping array element position constraints in the PSAS algorithm such as the extended towing line size algorithm for array expansion, resulting in the inability to effectively detect and distinguish underwater target signals

The passive synthetic aperture sonar algorithm of overlapping array elements (apertures) is generally used for the detection and resolution of target signals under ideal conditions. Considering the influence of complex factors such as underwater acoustic channels, the towed line array maintains a constant speed in practical applications to ensure that the overlapped underwater The same spatial position of the earphones is difficult to satisfy, and it does not have feasibility, versatility and practicability, so that the conventional signal detection and resolution methods of passive synthetic aperture sonar cannot be reasonably applied in engineering

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