Application of wavelet threshold de-noising in scattering optical wake flow signal processing
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Corresponding author:
ZHANG Xiao-hui, zhangxiaohui505@vip.sina.com
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Received Date:
2010-12-10
Accepted Date:
2010-11-04
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Abstract
For effectively detecting the backscattering optical wake flow signal from the noise,the collected original signal was transferred into one dimension discrete wavelets based on four Daubechies wavelet decomposition (db4WD) so that the low frequency term,indicating the backscattered signal from the shake waves,was distinguished from the high frequency terms, indicating noise.Then,the wavelet coefficients were obtained based on the threshold function.A new threshold function was put forward on the basis of wavelet soft and hard threshold de-noising method with entropies indicating the sparsity distribution of the original signal data.The new function can not only overcome discontinuity disadvantage of the hard threshold function,but also solve constant deviation in the soft threshold function.The new threshold function can effectively eliminate noise and overcome the disadvantage of soft and hard threshold function so that good results can be obtained.
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