Denoising Method for Shear Probe Signal Based on Wavelet Thresholding  

作　　者：王树新 肖学忠 王延辉 王子龙 陈宝阔 

机构地区：[1]School of Mechanical Engineering, Tianjin University

出　　处：《Transactions of Tianjin University》2012年第2期135-140,共6页天津大学学报（英文版）

基　　金：Supported by National Natural Science Foundation of China (No. 50835006 and No. 51005161);National High-Tech R&D Program ("863"Program) of China (No. 2010AA09Z102)

摘　　要：Shear probe works under a tough environment where the turbulence signals to be measured are very weak. The measured turbulence signals often contain a large amount of noise. Due to wide frequency band, noise signals cannot be effectively removed by traditional methods based on Fourier transform. In this paper, a wavelet thresholding denoising method is proposed for turbulence signal processing in that wavelet analysis can be used for multi-resolution analysis and can extract local characteristics of the signals in both time and frequency domains. Turbulence signal denoising process is modeled based on the wavelet theory and characteristics of the turbulence signal. The threshold and decomposition level, as well as the procedure of the turbulence signal denoising, are determined using the wavelet thresholding method. The proposed wavelet thresholding method was validated by turbulence signal denoising of the Western Pacific Ocean trial data. The results show that the propsed method can reduce the noise in the measured signals by shear probes, and the frequency spectrums of the denoised signal correspond well to the Nasmyth spectrum.Shear probe works under a tough environment where the turbulence signals to be measured are very weak. The measured turbulence signals often contain a large amount of noise. Due to wide frequency band, noise signals cannot be effectively removed by traditional methods based on Fourier transform. In this paper, a wavelet thresholding denoising method is proposed for turbulence signal processing in that wavelet analysis can be used for multi-resolution analysis and can extract local characteristics of the signals in both time and frequency domains. Turbulence signal denoising process is modeled based on the wavelet theory and characteristics of the turbulence signal. The threshold and decomposition level, as well as the procedure of the turbulence signal denoising, are determined using the wavelet thresholding method. The proposed wavelet thresholding method was validated by turbulence signal denoising of the Western Pacific Ocean trial data. The results show that the propsed method can reduce the noise in the measured sig- nals by shear probes, and the frequency spectrums of the denoised signal correspond well to the Nasmyth spectrum.

关 键 词：wavelet analysis THRESHOLD shear probe signal processing 

分 类 号：TN911.4[电子电信—通信与信息系统]