Method for testing and identifying underwater sound noise based on small wave area

A technology of wavelet domain and noise, which is applied in the field of target detection and recognition of naval weapons and equipment, can solve the problems of poor model practicability, large amount of calculation, and inability to realize ship noise detection, and achieve improved recognition rate and robustness, and improved detection capabilities Effect

Inactive Publication Date: 2005-04-27
SHANGHAI JIAO TONG UNIV
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Problems solved by technology

For the former modeling method, in reality, due to the complex structure of the hull itself, there are many sound sources causing noise, and the propagation channel cannot be accurately modeled, so it is almost impossible to establish an accurate mechanism model , and is not universal
The latter is to model ship noise from the perspective of statistical analysis, but the practicability of the model is poor, and the de

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  • Method for testing and identifying underwater sound noise based on small wave area
  • Method for testing and identifying underwater sound noise based on small wave area
  • Method for testing and identifying underwater sound noise based on small wave area

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Embodiment Construction

[0025] 1. Use a sampling rate of 512Hz to collect 0.25 second ship noise signals (under different transverse distances, different speeds, different tonnages and different sea conditions) and marine environmental noise x(t), with a length of 128 points. Taking these signals as training samples, first remove the mean of x(t) to get x 1 (t). to x 1 (t) is normalized (divided by the largest absolute value of the respective signals), and s(t) is obtained. Then choose the wavelet as the Haar wavelet, and perform wavelet decomposition on s(t) respectively, the maximum scale is 5, and the number of wavelet coefficients on the 5th scale is 8, thus forming 8 binary trees rooted at these 8 nodes. The wavelet coefficients on each node have two states M=2, and a tree structure in the wavelet domain is formed.

[0026] 2. Using the tree structure in the wavelet domain and using the EM (Mathematical Expectation Maximization) algorithm, obtain the respective HMT models of ship noise and ma...

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Abstract

The hydroacoustic noise detecting and distinguishing method based on wavelet domain includes the first mean value-eliminating and amplitude normalizing treatment of ship noise and marine environment noise, and the subsequent multiple scale domain decomposing of the wavelet domain and establishing implicit wavelet domain Markov model. Based on the characteristic difference between marine environment noise model and ship radiation noise model, one detection method based on Nyman-Pearson criterion is proposed. The likelihood value between the ship noise and the marine environment noise HMT model is used as the inspection statistic for binary hypothesis inspection to raise the ship noise detecting capacity. One characteristic vector describing the detection sample is formed for judging ship noise type, resulting in raised identification rate and robustness.

Description

technical field [0001] The invention relates to a detection and identification method of underwater acoustic noise based on wavelet domain (underwater acoustic noise is divided into ship noise and marine environment noise), relates to the fields of non-stationary signal processing, pattern recognition and data mining, and can be directly applied to the navy Target detection and recognition of weapons and equipment. Background technique [0002] Underwater acoustic technology is a method and technology that uses sound waves to detect, locate, track, identify, underwater communication, and navigation targets in water, on the seabed, and below the seabed. The sinking of the giant passenger ship "Titanic" in 1912 promoted the birth of modern underwater acoustic technology. In World War I, echolocation sonar appeared. During World War II, underwater acoustic technology developed greatly, sonar equipment was improved, and acoustic guidance torpedoes and acoustic mines appeared. ...

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Application Information

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IPC IPC(8): G01H3/00G01H17/00G01S7/539G01S15/88
Inventor 周越
Owner SHANGHAI JIAO TONG UNIV
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