A Method for Measuring Echo Reduction of Acoustic Overlay Based on Compressive Sensing Technology

Abstract

The invention discloses a method for measuring echo reduction of an acoustic overlay layer based on compressed sensing technology. The method is based on the sparse characteristics of acoustic channels in a limited test space, and uses compressed sensing technology to process broadband signals to obtain accurate estimation of multipath channel time delay. On this basis, the least square method is used to estimate the amplitude of the sample reflection wave of the frequency point signal to be measured, so as to realize the extraction of the sample echo and the accurate measurement of the echo reduction under the condition of low frequency strong reverberation. The invention realizes the separation of the reflected echo and the direct wave of each sound-absorbing layer in the measurement of large-scale echo reduction of the acoustic covering layer under the condition of low frequency and limited space, and further improves the existing echo reduction measurement technology of the acoustic covering layer in the low-frequency range and multi-layer The accuracy of the measurement results in the shell model test; it can effectively reduce the measurement error and improve the measurement accuracy, while simplifying the experimental process and reducing the workload required for measurement.

Description

technical field [0001] Underwater acoustic coatings are widely used and crucial underwater components in underwater acoustic engineering. In order to evaluate the echo reduction performance of acoustic coating samples, the echo reduction measurement of large samples under laboratory conditions is an essential Link, the invention relates to a method for measuring the echo reduction of a large sample of an underwater acoustic covering layer. Background technique [0002] Acoustic covering layer refers to the special functional acoustic materials and structures laid on the underwater parts, mainly composed of a series of products with different acoustic functions such as anechoic tiles, sound insulation tiles, vibration suppression tiles, decoupling tiles, array mufflers, etc. Acoustic protection system. On the one hand, the acoustic covering layer can absorb active detection sound waves and reduce the acoustic target intensity of underwater structures, and on the other hand, ...

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Problems solved by technology

In a limited space environment, the reverberation and multipath effects are serious, and the precise decomposition of the plane wave cannot be realized, thus limiting the application of the spatial Fourier transform method; the broadband pulse compression method can realize the focus of the pulse signal waveform in the time domain, but under low frequency conditions, The characteristics of its single-channel transmission lead to poor directivity, serious diffraction and reverberation interference; the acoustic focusing method is a test technology under waveguide conditions, and multipath information is superimposed in the direct wave and sample echo, which is different from the plane wave test technology. difference

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