摘要
地震信号具有非线性、非平稳的特性,用时频分析的方法处理地震信号,可以最大限度的保留原始信息,也可以较为精确地分析数据的时间、频率特征.现阶段应用于地震数据处理的时频分析方法主要有:短时傅里叶变换,小波变换和匹配追踪算法等等.S变换是近几年发展起来的一种新的时频分析方法.S变换结合了短时傅里叶变换和小波变换的优点,具有相位信息,同时该变换与小波变换一样,其时频窗可以调节大小以适应非平稳信号的特点.S变换的这些优点,使得它在地球物理方面得到广泛的应用.但是针对于S变换窗函数特性定量分析及其改进的文章较少,本文首先通过具体的实验说明了S变换的不足之处,然后通过理论分析,剖析了S变换的时频特性.指出了导致该变换不足之处的根源.最后指出了相应的改进办法,并且通过实验验证了改进后的S变换确实是对原来S变换的一种提高.
Seismic signals have nonlinear, non-stationary properties. Using time frequency method to process seismic signals could reserve the primary information of the data in maximal extend, and accurately analyze the properties of the data in the time frequency domain. Until now, there are many time frequency methods, such as the short time Fourier transform（STFT）, the wavelet transform（WT） and the matching pursuit method（MP）, and so on. The S transform is a new time-frequency method developed in recent years. The transform takes both the advantages of short time Fourier transform and the wavelet transform, that is to say the transform has phase information just as the STFT and its time frequency windows adjust adaptively according to the non-stationary signal just as the WT. These advantages make it is used widely in geophysics area. However, there are few papers quantitatively discussing the time frequency properties of the S transform. This paper points out the shortages of the S transform through experiments, finds the root of the shortages by theories analysis and points out the ways to improve the S transform. Furthermore, experiments conducted validate that the remedy ways are indeed effective.
出处
《地球物理学进展》
CSCD
北大核心
2011年第5期1661-1667,共7页
Progress in Geophysics
基金
中国石油大学(北京)基础学科基金:储层预测中新的谱分解方法研究(JCXK-2011-122)
国家自然科学基金项目:油藏数值模拟中新算法的应用研究(10926108)项目联合资助
关键词
短时傅里叶变换
小波变换
S变换
时频分析
short time Fourier transform, wavelet transform, S transform, time frequency analysis
