A method and system for enhancing spectral features of distortion dragged arrays

Abstract

The present invention discloses a method and system for enhancing the spectrum feature of the distortion dragging array, wherein the method includes: 1. Obtaining the observation array signal x i (t); 2. Roughly estimate the target orientation based on ideal beamforming as the steering angle when the target signal beam energy is maximum; 3. Detect the L frequencies with the highest power of the target signal and calculate the array relative delay difference vector of L strong line spectra Γ l ; 4. Use the weighted Kalman filter to reduce the array relative delay difference vector Γ l 5. Based on the estimated time delay, the target tracking beam is obtained to obtain the line spectrum features with enhanced fidelity through Fourier transform. This method can correct the distortion of the towed line array and the effect of the delay vector outlier on the beamforming under the condition of low signal-to-noise ratio, and realize the line spectrum feature enhancement of the distorted towed array in the multi-target strong interference underwater acoustic environment.

Description

technical field [0001] The invention belongs to the technical field of sonar signal processing, and in particular relates to a method and a system for enhancing the line spectrum characteristics of a distorted towed array in a strong interference underwater environment. Background technique [0002] Among the various energy forms known so far, the propagation performance of sound waves in water is the best. People have been using sound waves to locate, track and identify underwater or surface targets. The equipment with this function is called sonar. At present, the sonar system is mainly divided into hydrophone shore-based array sonar and hydrophone towed line array sonar. The hydrophone towed line array sonar is referred to as the towed array, which is an acoustic detection system towed at a certain distance at the stern of the ship. related parameters. It has the characteristics of strong detection ability, low detection frequency, strong hydrological adaptability and ...

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.

For self-calibration algorithms, there are still outliers in the delay of some array elements with low signal-to-noise ratio, which will lead to the degradation of beamforming performance.

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