A method and system for enhancing spectral features of distorted towed fronts

Abstract

The present invention discloses a method and system for enhancing the characteristics of the distortion towed front spectrum, wherein the method includes: 1. Obtaining the observation array signal; 2. Roughly estimating the target orientation based on ideal beamforming; 3. Detecting L frequencies with the highest power of the target signal , to calculate the relative delay difference vector Γ of the strong line spectrum array l ; 4. The relative delay difference vector Γ of the L strong line spectrum arrays l Fitting to L curves; 5. Use the hierarchical clustering algorithm based on Frechet distance to classify the L curves to obtain a classification cluster set; 6. Select the class with the most line spectrum in the classification results to obtain the relative time delay of the array to eliminate the influence of strong interference Difference vector estimation Γ'; 7. Acquire the target tracking beam based on the estimated time delay, and obtain the line spectrum feature with enhanced fidelity through Fourier transform. This method eliminates the influence of the strong interference line spectrum on the time delay estimation by fitting-hierarchical clustering, and obtains the target radiation noise tracking beam based on the estimated time delay. Enhanced spectral features.

Description

technical field [0001] The invention belongs to the technical field of sonar signal processing, and in particular relates to a method and system for enhancing line spectrum features of a distorted towed array in a strong-interference underwater environment. Background technique [0002] Compared with the traditional hull sonar, the towed line array, on the one hand, is not restricted by the geometric size of the hull, so it can deploy more hydrophones, increase the sonar aperture, and has the ability to receive low-frequency and even very low-frequency sound waves; , because the towed line array is far away from the working mother ship, the influence of platform noise is reduced, and the receiving signal-to-noise ratio is significantly improved; these characteristics greatly improve the detection capability of the towed sonar. However, the acoustic section of the linear array is usually flexible due to dragging. In practical applications, after the towline is deployed in th...

AI Technical Summary

Problems solved by technology

But for some array structures, such as equidistant line arrays, the unique identification of parameter estimates is often not guaranteed

More importantly, the high-dimensional, multi-modal, and nonlinear optimization problems corresponding to the joint estimation of parameters in the self-calibration algorithm bring a huge amount of computation, and the global convergence of parameter estimation is often not guaranteed.

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