基于改进经验模态分解的地震弱信号增强处理方法
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摘要
针对地震反射信号经验模态(EMD)分解过程中出现的混叠及分解重建失真等问题,本文提出一种改进的EMD分解方法.首先对地震信号进行小波转换,对转换分解得到的信号高频部分进行噪声压制处理,然后将转换后的结果再进行EMD分解;针对频带宽度、振幅大小变换,提出了地震信号EMD分解的分段控制停止准则,根据主频带宽,确定相应的时窗长度,并采用各个时窗段部分叠置衔接的方法,最后对每段结果再利用单调函数停止准则进行变换,该方法有效避免了计算结果的时窗效应.通过实际资料处理对比分析,改进的EMD分解方法较以往常规EMD分解方法,在分解结果的可靠性、分解精度及非线性弱信号时频分析能力等方面都具有显著的改善,为提高薄层地质体识别能力提供了有力的技术手段.
Based on the discussion of the reflection seismic signals aliasing problems in the process of Empirical Mode Decomposition(EMD) and the distortion of reconstruction, we put forward the improved Empirical Mode Decomposition(EMD) to ameliorate the shortcomings of the existing methods to solve the problem of aliasing and the stopping criteria. At first,the seismic signal is transformed by the wavelet transform. And then we put the results to the EMD decomposition and the high frequency part of the noise is suppressed.In view of the seismic signal frequency band width and amplitude transform, we studied the piecewise control stopping criteria of the EMD.The length of time window is determined by the frequency bandwidth. We use various windows overlap connection method to avoid the calculation results of effect of time window.At last we get the results using monotone function stop criterion.Through the application effect analysis of actual data,we can find that the improved EMD has significant improvement in many ways such as the reliability of the results, precision and the time-frequency analysis ability of nonlinear weak signal.
Based on the discussion of the reflection seismic signals aliasing problems in the process of Empirical Mode Decomposition(EMD) and the distortion of reconstruction, we put forward the improved Empirical Mode Decomposition(EMD) to ameliorate the shortcomings of the existing methods to solve the problem of aliasing and the stopping criteria. At first,the seismic signal is transformed by the wavelet transform. And then we put the results to the EMD decomposition and the high frequency part of the noise is suppressed.In view of the seismic signal frequency band width and amplitude transform, we studied the piecewise control stopping criteria of the EMD.The length of time window is determined by the frequency bandwidth. We use various windows overlap connection method to avoid the calculation results of effect of time window.At last we get the results using monotone function stop criterion.Through the application effect analysis of actual data,we can find that the improved EMD has significant improvement in many ways such as the reliability of the results, precision and the time-frequency analysis ability of nonlinear weak signal.
引文
DU Xianfeng,LI Z-J,BI F-R,et al. 2012. Source Separation of Diesel Engine Vibration Based on the Empirical Mode Decomposition and Independent Component Analysis [J]. Chinese Journal of Mechanical Engineering,25(3): 557-563.
JIA R-S,ZHAO T-B,SUN H-M,et al. 2015. Micro-seismic signal denoising method based on empirical mode decomposition and independent component analysis [J]. Chinese Journal of Geophysics (in Chinese),58(3): 1013-1023,doi: 10.6038/cjg20150326.贾瑞生,赵同彬,孙红梅,等. 2015. 基于经验模态分解及独立成分分析的微震信号降噪方法[J]. 地球物理学报,58(3): 1013-1023,doi: 10.6038/cjg20150326.
LI Y,PENG J-L,MA H-T,et al. 2013. Study of the influence of transition IMF on EMD do-noising and the improved algorithm [J]. Chinese Journal of Geophysics (in Chinese),56(2): 626- 634,doi: 10.6038/cjg20130226.李月,彭蛟龙,马海涛,等. 2013. 过渡内蕴模态函数对经验模态分解去噪结果的影响研究及改进算法[J]. 地球物理学报,56(2): 626- 634,doi: 10.6038/cjg20130226.
PAN H,BU M-S. 2014. Pressure fluctuation signal analysis of pump based on ensemble empirical mode decomposition method [J]. Water Science and Engineering,7(2): 227-235.
QIANG C-S,LIU D-Z,LIU Z-G,et al. 2010. EMD based on recursive high-pass filter and its application on seismic signal analysis [J]. Chinese Journal of Geophysics (in Chinese),53(5): 1215-1225,doi: 10.3969/j.issn.0001-5733.2010.05.024.钱昌松,刘代志,刘志刚,等. 2010. 基于递归高通滤波的经验模态分解及其在地震信号分析中的应用[J]. 地球物理学报,53(5): 1215-1225,doi: 10.3969/j.issn.0001-5733.2010.05.024.
Shi C-X,Luo Q-F. 2003. Hilbert-Huang transform and wavelet analysis of time history signal [J]. Acta seismologica sinica (in Chinese),25(4): 398- 405,doi: 10.3321/j.issn:0253-3782.2003.04.007.石春香,罗奇峰. 2003. 时程信号的Hilbert-Huang变换与小波分析[J]. 地震学报,25(4): 398- 405,doi: 10.3321/j.issn:0253-3782.2003.04.007.
SONG W-Q,ZHANG Y,WU C-D et al. 2017. The method of weak seismic reflection signal processing and extracting based on multitrace joint compressed sensing [J]. Chinese Journal of Geophysics (in Chinese),60(8): 3238-3245,doi: 10.6038/cjg20170828.宋维琪,张宇,吴彩端,等. 2017. 多道联合压缩感知弱小反射地震信号提取处理方法[J]. 地球物理学报,60(8): 3238-3245,doi: 10.6038/cjg20170828.
WANG Z-W,LIU J-H,NIE C-Y. 2008. Application of Hilbert-Huang transform in extracting dynamic properties of array acoustic signals [J]. Progress in Geophysics (in Chinese),23(2): 450- 455.王祝文,刘菁华,聂春燕. 2008. Hilbert-Huang变换在提取阵列声波信号动力特性中的应用[J]. 地球物理学进展,23(2): 450- 455.
WU Y,MENG X-H,LI S-L. 2012. Wavelet analysis and its application in geophysics of China [J]. Progress in Geophysics (in Chinese),27(2): 750-760,doi: 10.6038/j.issn.1004-2903.2012.02.043.武粤,孟小红,李淑玲. 2012. 小波分析及其在我国地球物理学研究中的应用进展[J]. 地球物理学进展,27(2): 750-760,doi: 10.6038/j.issn.1004-2903.2012.02.043.
Xu X-G,Xu G-L,Wang X-T,et al. 2009. Empirical mode decomposition and its application [J]. Acta electronica sinica (in Chinese),37(3): 581-585.徐晓刚,徐冠雷,王孝通,等. 2009. 经验模式分解(EMD)及其应用[J]. 电子学报,37(3): 581-585.
YAN Z-H,LUAN X-W,WANG Y,et al. 2017. Seismic random noise attenuation based on empirical mode decomposition of fractal dimension [J]. Chinese Journal of Geophysics (in Chinese),60(7): 2845-2857,doi: 10.6038/cjg20170729.颜中辉,栾锡武,王赟,等. 2017. 基于经验模态分解的分数维地震随机噪声衰减方法[J]. 地球物理学报,60(7): 2845-2857,doi: 10.6038/cjg20170729.
YANG P-J,YIN X-Y,ZHANG G-Z. 2007. Seismic signal time-frequency analysis and attributes extraction based on HHT [J]. Progress in Geophysics (in Chinese),22(5): 1585-1590,doi: 10.3969/j.issn.1004-2903.2007.05.037.杨培杰,印兴耀,张广智. 2007. 希尔伯特-黄变换地震信号时频分析与属性提取[J]. 地球物理学进展,22(5): 1585-1590,doi: 10.3969/j.issn.1004-2903.2007.05.037.
ZHANG Y,PAN B-Z,HE S-L,et al. 2012. Identification of the features of wavelet analysis based reservoir fluid [J]. Progress in Geophysics (in Chinese),27(6): 2554-2560,doi: 10.6038/j.issn.1004-2903.2012.06.032.张莹,潘保芝,何胜林,等. 2012. 基于小波分析的储层流体性质识别[J]. 地球物理学进展,27(6): 2554-2560,doi: 10.6038/j.issn.1004-2903.2012.06.032.
ZHANG Z-J,GU C-S,BAO T-F,et al. 2010. Application analysis of empirical mode decomposition and phase space reconstruction in dam time-varying characteristic [J]. Science China (Technological Sciences),53(6): 1711-1716,doi: 10.1007/s11431- 010-3098-1.
Zhao W,Jiang Z X,Qiu L W,et al. 2010. Geological concept,method and application of sequence unit identification through wavelet analysis [J]. Oil & Gas Geology (in Chinese),31(4): 436- 441.赵伟,姜在兴,邱隆伟,等. 2010. 小波分析划分层序单元的地质学理论基础、方法与应用[J]. 石油与天然气地质,31(4): 436- 441.
JIA R-S,ZHAO T-B,SUN H-M,et al. 2015. Micro-seismic signal denoising method based on empirical mode decomposition and independent component analysis [J]. Chinese Journal of Geophysics (in Chinese),58(3): 1013-1023,doi: 10.6038/cjg20150326.贾瑞生,赵同彬,孙红梅,等. 2015. 基于经验模态分解及独立成分分析的微震信号降噪方法[J]. 地球物理学报,58(3): 1013-1023,doi: 10.6038/cjg20150326.
LI Y,PENG J-L,MA H-T,et al. 2013. Study of the influence of transition IMF on EMD do-noising and the improved algorithm [J]. Chinese Journal of Geophysics (in Chinese),56(2): 626- 634,doi: 10.6038/cjg20130226.李月,彭蛟龙,马海涛,等. 2013. 过渡内蕴模态函数对经验模态分解去噪结果的影响研究及改进算法[J]. 地球物理学报,56(2): 626- 634,doi: 10.6038/cjg20130226.
PAN H,BU M-S. 2014. Pressure fluctuation signal analysis of pump based on ensemble empirical mode decomposition method [J]. Water Science and Engineering,7(2): 227-235.
QIANG C-S,LIU D-Z,LIU Z-G,et al. 2010. EMD based on recursive high-pass filter and its application on seismic signal analysis [J]. Chinese Journal of Geophysics (in Chinese),53(5): 1215-1225,doi: 10.3969/j.issn.0001-5733.2010.05.024.钱昌松,刘代志,刘志刚,等. 2010. 基于递归高通滤波的经验模态分解及其在地震信号分析中的应用[J]. 地球物理学报,53(5): 1215-1225,doi: 10.3969/j.issn.0001-5733.2010.05.024.
Shi C-X,Luo Q-F. 2003. Hilbert-Huang transform and wavelet analysis of time history signal [J]. Acta seismologica sinica (in Chinese),25(4): 398- 405,doi: 10.3321/j.issn:0253-3782.2003.04.007.石春香,罗奇峰. 2003. 时程信号的Hilbert-Huang变换与小波分析[J]. 地震学报,25(4): 398- 405,doi: 10.3321/j.issn:0253-3782.2003.04.007.
SONG W-Q,ZHANG Y,WU C-D et al. 2017. The method of weak seismic reflection signal processing and extracting based on multitrace joint compressed sensing [J]. Chinese Journal of Geophysics (in Chinese),60(8): 3238-3245,doi: 10.6038/cjg20170828.宋维琪,张宇,吴彩端,等. 2017. 多道联合压缩感知弱小反射地震信号提取处理方法[J]. 地球物理学报,60(8): 3238-3245,doi: 10.6038/cjg20170828.
WANG Z-W,LIU J-H,NIE C-Y. 2008. Application of Hilbert-Huang transform in extracting dynamic properties of array acoustic signals [J]. Progress in Geophysics (in Chinese),23(2): 450- 455.王祝文,刘菁华,聂春燕. 2008. Hilbert-Huang变换在提取阵列声波信号动力特性中的应用[J]. 地球物理学进展,23(2): 450- 455.
WU Y,MENG X-H,LI S-L. 2012. Wavelet analysis and its application in geophysics of China [J]. Progress in Geophysics (in Chinese),27(2): 750-760,doi: 10.6038/j.issn.1004-2903.2012.02.043.武粤,孟小红,李淑玲. 2012. 小波分析及其在我国地球物理学研究中的应用进展[J]. 地球物理学进展,27(2): 750-760,doi: 10.6038/j.issn.1004-2903.2012.02.043.
Xu X-G,Xu G-L,Wang X-T,et al. 2009. Empirical mode decomposition and its application [J]. Acta electronica sinica (in Chinese),37(3): 581-585.徐晓刚,徐冠雷,王孝通,等. 2009. 经验模式分解(EMD)及其应用[J]. 电子学报,37(3): 581-585.
YAN Z-H,LUAN X-W,WANG Y,et al. 2017. Seismic random noise attenuation based on empirical mode decomposition of fractal dimension [J]. Chinese Journal of Geophysics (in Chinese),60(7): 2845-2857,doi: 10.6038/cjg20170729.颜中辉,栾锡武,王赟,等. 2017. 基于经验模态分解的分数维地震随机噪声衰减方法[J]. 地球物理学报,60(7): 2845-2857,doi: 10.6038/cjg20170729.
YANG P-J,YIN X-Y,ZHANG G-Z. 2007. Seismic signal time-frequency analysis and attributes extraction based on HHT [J]. Progress in Geophysics (in Chinese),22(5): 1585-1590,doi: 10.3969/j.issn.1004-2903.2007.05.037.杨培杰,印兴耀,张广智. 2007. 希尔伯特-黄变换地震信号时频分析与属性提取[J]. 地球物理学进展,22(5): 1585-1590,doi: 10.3969/j.issn.1004-2903.2007.05.037.
ZHANG Y,PAN B-Z,HE S-L,et al. 2012. Identification of the features of wavelet analysis based reservoir fluid [J]. Progress in Geophysics (in Chinese),27(6): 2554-2560,doi: 10.6038/j.issn.1004-2903.2012.06.032.张莹,潘保芝,何胜林,等. 2012. 基于小波分析的储层流体性质识别[J]. 地球物理学进展,27(6): 2554-2560,doi: 10.6038/j.issn.1004-2903.2012.06.032.
ZHANG Z-J,GU C-S,BAO T-F,et al. 2010. Application analysis of empirical mode decomposition and phase space reconstruction in dam time-varying characteristic [J]. Science China (Technological Sciences),53(6): 1711-1716,doi: 10.1007/s11431- 010-3098-1.
Zhao W,Jiang Z X,Qiu L W,et al. 2010. Geological concept,method and application of sequence unit identification through wavelet analysis [J]. Oil & Gas Geology (in Chinese),31(4): 436- 441.赵伟,姜在兴,邱隆伟,等. 2010. 小波分析划分层序单元的地质学理论基础、方法与应用[J]. 石油与天然气地质,31(4): 436- 441.