Beam-domain Time-Frequency Analysis Method for Ship Line Spectrum Noise Source Location

Abstract

The invention provides a wave beam domain time-frequency analysis method for warship line spectrum noise source positioning. The wave beam domain time-frequency analysis method comprises the following steps: performing frequency domain filtering and super-directivity beam forming to the signals received by an array, that is, performing spatial filtering and constituent isolation on the time domain, so as to realize space-time-frequency domain combined processing of the signals; estimating the abeam moment of each line spectrum noise source, and referring to the synchronous acoustic beacon information to estimate the longitudinal position distribution of the line spectrum noise source along the warship. The wave beam domain time-frequency analysis method disclosed by the invention adopts the high-order super-directivity beam forming algorithm to greatly shrink the physical size of the receiving array and improve the actual operability of the measuring method on the premise of maintaining the receptivity; the space-time-frequency domain combined processing to the received signals is used for extracting the signal constituents of each line spectrum noise source; the time-frequency analysis method is used for obtaining the accurate time-frequency domain distribution diagram of the Doppler signals and accurately estimating the Doppler inflexions, so as to realize noise source position estimation of the high-precision multi-line spectrum and the same-frequency line spectrum.

Description

technical field [0001] The invention relates to the field of underwater acoustic measurement, in particular to estimation of ship line spectrum noise source position. Background technique [0002] The spectrum of ship radiated noise is mainly composed of the mixed spectrum formed by the superposition of continuum spectrum and line spectrum. Among them, the line spectrum noise reflects the periodic components in the noise signal, concentrated in the low frequency band below 1kHz. In the underwater radiation noise of ships, the radiation sources of different frequency bands have different radiation parts on the ship. The radiation sound of several hundred Hz is mainly excited by the mechanical vibration source, and the area where the main engine and auxiliary engine are located may be its radiation source location. The low-frequency line spectrum of tens of hertz is mainly produced by reciprocating mechanical noise, propeller blade resonance line spectrum and blade velocity ...

AI Technical Summary

Problems solved by technology

Due to the low frequency band of ship radiation noise, the size of the receiving array is required to be quite large, which will bring a lot of inconvenience in practical application

For moving targets in water, domestic scholar Shi Jie et al. (Shi Jie, Yang Desen, Shi Shengguo. Research on Robust Focusing and Localization Recognition Method of Moving Sound Source Based on Worst Performance Optimization. Acta Physica Sinica, 2011,60(6):1-11) Using the method of passive synthetic aperture, a linear array deployed on the seabed is virtualized into a large-scale planar array, so as to realize the localization of noise sources in the near field, but this method has strict restrictions on the speed of ship movement

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