Improved automatic line spectrum extraction method

Abstract

The invention relates to the technical field of target line spectrum detection and feature extraction of hydroacoustics and underwater acoustic signal processing, in particular to an improved automatic line spectrum extraction method, which can effectively filter false alarm noise line spectrums and realize an interference purification function of the line spectrums. Meanwhile, by utilizing a Kalman filtering tracking technology, the method can effectively realize stable tracking of line spectrums which are relatively weak in signal-to-noise ratio, discontinuous in track and relatively large in frequency change, and can independently and accurately track a plurality of harmonic line spectrums which are close in frequency and relatively large in change, so that the problem of error tracking is avoided; the method can finally realize automatic extraction of the long-time characteristics of the line spectrum, provides powerful support for subsequent target classification and recognition, and has a good application prospect.

Description

technical field [0001] The invention relates to the technical field of target line spectrum detection and feature extraction of underwater acoustics and underwater acoustic signal processing, and the specific field is an improved automatic line spectrum extraction method. Background technique [0002] Passive sonar target classification and recognition, as the main function of sonar systems such as submarines, surface ships, and shore-based warnings, is a key technical field for the development of various countries and has important military application value. Its performance is determined by the strength of naval combat capabilities important manifestation. At present, passive target classification and recognition is mainly realized by analyzing target radiation noise and extracting related features such as power spectrum and modulation spectrum that represent the physical properties of the target. The power spectrum of ship radiated noise is composed of line spectrum and ...

AI Technical Summary

Problems solved by technology

However, in reality, due to changes in ship target working conditions, changes in motion state, changes in underwater acoustic channels, and fluctuations in environmental noise, the frequency and signal-to-noise ratio of the target line spectrum present time-varying characteristics. At this time, line spectrum broadening, frequency Problems such as drift and trajectory discontinuity have brought great difficulties to the estimation of target line spectrum features

It is difficult to obtain some long-term features of the line spectrum, such as frequency position stability, line spectrum intensity stability, and line spectrum migration velocity, by only relying on short-term line spectrum feature extraction methods, which restricts Doppler velocity estimation, harmonic sequence discrimination, etc. processing

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