Wide beam interference suppression method for weak target detection

Abstract

The invention provides a wide beam interference suppression method for weak target detection, which comprises the following steps: step 1) receiving a broadband signal of a long-distance target by a space linear array, and performing fast Fourier transform on the signal received by each array element of the linear array in a time domain to generate a time domain frequency spectrum of each array element signal of the linear array; dividing the space linear array into a plurality of overlapped sub-arrays; performing phase compensation on the signal time domain spectrum of the overlapped subarrays to form beam domain output and obtain a subarray azimuth spectrogram; 2) utilizing a sub-array azimuth spectrogram, determining an interference orientation, performing interference suppression weighting on the beam domain output, correcting the interference suppression weighting by using the expected null width to obtain null weighting, and controlling the interference suppression width of the beam domain output to obtain an orientation spectrogram after interference suppression, thereby realizing suppression of strong interference and detection of a weak target under a strong interference background. According to the invention, a strong interference signal of a wide beam is effectively suppressed, the detection performance of a weak target is improved, and the output signal-to-interference ratio is improved; sea test data proof validity.

Description

technical field [0001] The invention belongs to the field of sonar digital signal processing, in particular to a wide beam interference suppression method for weak target detection. Background technique [0002] The detection of weak signals is one of the key technologies of array signal processing. The spectral peak of the weak target in the strong interference background on the spatial spectrum is covered by the side lobes of the interference spectrum, which has a great impact on the detection of weak signals and the estimation of direction of arrival. Therefore, the interference should be effectively suppressed first. [0003] Scholars at home and abroad have conducted extensive and in-depth research on the interference suppression problem, and proposed many effective solutions, such as document 1 [Robust generalized sidelobe canceller with an eigenanalysis-based blocking matrix. International conference on electrical engineering and automation control, 2017] and Docume...

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Problems solved by technology

[0005] The purpose of the present invention is to overcome the slow calculation speed of the existing interference suppression algorithm, the low feasibility and the need for multiple peak-finding suppression near the wide-beam interference azimuth in practical applications, and at the same time, it is sensitive to random phase disturbances in complex ocean environments. Disadvantages that cause unsatisfactory interference suppression effect

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