小波变换在地震信号噪声处理中的应用
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摘要
常规小波域阈值去噪方法未能充分利用地震信号相关性的特点进行去噪 ,只能去除地震信号中部分随机噪声 ,为此提出了一种小波域分时分频相关结合阈值去噪处理方法。该方法首先对小波变换后多个尺度上小波系数进行分时分频相关去噪处理 ,然后对处理后小波系数进行重构 ,并可去除大部分不相关随机噪声。对重构后地震信号再进行常规小波域阈值去噪处理以进一步去除噪声。模型测试和实际资料处理效果表明 :使用该方法可以有效地改进地震信号去噪处理效果
Conventional de-noising methods by threshold filter in wavelet domain do not utilize the correlations of seismic data to remove random noises. So we propose a new and we believe better method which we call de-noising method. This de-noising method combines time-frequency analysis with threshold filter in wavelet domain. We explain in much detail how to use time-frequency correlation analysis to analyze correlations of seismic data, i.e., to analyze wavelet coefficients of multi-scales; after correlation analysis, we reconstruct these wavelet coefficients; in this way, most random noises can be removed. We then use conventional de-noising method by threshold filter in wavelet domain to remove more noises. We applied our new de-noising method to seismic data and did succeed in removing most random noises and raising SNR (signal-to-noise ratio).
Conventional de-noising methods by threshold filter in wavelet domain do not utilize the correlations of seismic data to remove random noises. So we propose a new and we believe better method which we call de-noising method. This de-noising method combines time-frequency analysis with threshold filter in wavelet domain. We explain in much detail how to use time-frequency correlation analysis to analyze correlations of seismic data, i.e., to analyze wavelet coefficients of multi-scales; after correlation analysis, we reconstruct these wavelet coefficients; in this way, most random noises can be removed. We then use conventional de-noising method by threshold filter in wavelet domain to remove more noises. We applied our new de-noising method to seismic data and did succeed in removing most random noises and raising SNR (signal-to-noise ratio).
引文
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[2] 章 珂,刘贵忠等.二进小波变换方法的地震信号分时分频去噪处理.地球物理学报,1996,39(2):265～271
[3] MallatS G,HangW L .SingularityDetection andProcessing withWavelets.IEEE Trans onInformationTheory,1992,38(2):617～643
[4] 刘贵忠,邸双亮.小波分析及其应用.西安:西安电子科技大学出版社,1992
[5] 俞寿朋.高分辨率地震勘探.北京:石油工业出版社.1993
[2] 章 珂,刘贵忠等.二进小波变换方法的地震信号分时分频去噪处理.地球物理学报,1996,39(2):265～271
[3] MallatS G,HangW L .SingularityDetection andProcessing withWavelets.IEEE Trans onInformationTheory,1992,38(2):617～643
[4] 刘贵忠,邸双亮.小波分析及其应用.西安:西安电子科技大学出版社,1992
[5] 俞寿朋.高分辨率地震勘探.北京:石油工业出版社.1993
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