Transform Domain Extraction Method of Single Component Acoustic Scattering Echo of Small Underwater Target

Abstract

The invention provides a method for extracting the single-component acoustic scattering echo of an underwater small target in a transformation domain. Using the transformation domain blind separation to enhance the acoustic scattering echo components of different categories respectively; then design the acoustic scattering echo screening scheme to solve the problem of random output order of the blind separation algorithm; then design the transformation domain feature extraction method to complete the different categories The determination of the characteristic parameters of the echo finally obtains a pure single-component echo signal. Compared with the traditional method, the present invention can obtain higher-quality single-component echo signals, and can be executed automatically, and has high practical value. The invention can be applied in the fields of detection and identification of underwater targets, sound scattering theory research and the like.

Description

technical field [0001] The invention relates to an underwater acoustic signal processing method, in particular to a method for extracting a single-component acoustic scattering echo signal of an active sonar target aiming at the acoustic scattering problem of small underwater targets. Background technique [0002] The particularity of the marine environment makes the traditional communication and detection methods based on electromagnetic waves impossible to realize underwater. As the only known means of long-distance transmission underwater, sound waves have become the main means of underwater detection and communication. . For quiet small targets, active sonar can only be used for detection in most cases. At the same time, due to the small size of the target, the geometric echo based on the linear acoustic theory is difficult to distinguish the target echo from the echoes of other obstacles in the environment. The elastic acoustic scattering echo can be used to distingui...

AI Technical Summary

Problems solved by technology

The generation process of geometric echo is simple and follows the law of linear acoustics, so the signal processing method for geometric echo is relatively mature; while the mechanism of elastic echo is complex, it does not exist stably under all incident angles, and its energy is generally weaker than that of geometric echo. waves, so the extraction and analysis of elastic echoes are difficult

[0004] Traditional signal processing methods such as time-frequency analysis and wavelet transform are difficult to obtain relatively pure single-component acoustic scattering echo signals due to the limitation of resolution; matched filtering can get a good processing effect on geometric echo, but for elastic Echo processing is difficult

This is because matched filtering needs to know a lot of prior information, and the current research on elastic echo is still difficult to provide enough prior information to meet the needs of matched filtering.

[0005] The blind separation method can obtain an estimate of the source signal when the prior information is unknown, but this method usually requires the source signals to be independent of each other

In the process of experimental data processing, it is found that the blind separation algorithm can only strengthen the geometric echo and the elastic echo separately, and cannot achieve the purpose of complete separation, because the independence of the signal in the actual situation is difficult to satisfy

Xia Zhi and Li Xiukun proposed the method of converting the linear frequency modulation signal into a single-frequency signal and performing narrow-band filtering, which can extract relatively pure geometric and elastic echo components, but the narrow-band filter parameter design method given by the author needs to be artificially specified. This limits the automated application of the algorithm

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