S变换在面波去噪中的应用

英文篇名：Application of S transform in surface wave denoising
中文刊名：地震学报
英文刊名：Acta Seismologica Sinica
作者：李玲利 ; 王清东 ; 沈文渊 ; 朱良保
英文作者：Li Lingli1 ; 2) ; Wang Qingdong3) Shen Wenyuan4) Zhu Liangbao3 ; 5) 1) University of Science and Technology of China ; Hefei 230026 ; China 2) Earthquake Administration of Anhui Province ; Hefei 230031 ; China 3) Department of Geophysics ; School of Geodesy and Geomatics ; Wuhan University ; Wuhan 430079 ; China 4) Institute of Electronics ; Chinese Academy of Sciences ; Beijing 100190 ; China 5) Key Laboratory of Geospace Enviroment and Geodesy ; Ministry of Education ; Wuhan University ; Wuhan 430079 ; China
中文关键词：S变换 ; 时频滤波 ; 阈值滤波 ; 频散曲线 ; 相位匹配滤波
英文关键词：S transform ; time-frequency filter ; threshold filter ; dispersion curves ; phase match filter
出版日期：2012-11-15
机构：中国科学技术大学;安徽省地震局;武汉大学测绘学院地球物理系;中国科学院电子学研究所;武汉大学地球空间环境与大地测量教育部重点实验室;
年：2012
期：06
出版单位：地震学报

摘要

S变换是一种用于分析非平稳信号的时频变换方法,可以很好地刻画地震信号的时频特性.本文将S变换用于地震面波数据的噪声去除中,首先介绍了S变换的理论基础,然后设计了时频滤波和阈值滤波两种方法,分别对天然地震面波数据和背景噪声数据进行去噪处理,并与相位匹配滤波进行了比较.结果表明,面波数据经S变换去噪后,群速度频散曲线的短周期部分得到改善,能够连续追踪至6s左右,但长周期部分出现了缺失;S变换去噪的效果优于相位匹配滤波,两者相结合会得到更加理想的结果.
S transform is a time-frequency transformation method used to analyze non-stationary signals,and it can depict the time-frequency characteristics of seismic signals very well.In this paper,S transform is used to remove noises in seismic surface wave data.The theoretical basis of S transform is introduced first,and then time-frequency filter and threshold filter are designed for processing ambient noise data and surface wave data of natural earthquakes,respectively.The results show that the short period part of group velocity dispersion curve of surface wave data is improved after S transform denoising,and the group velocity can be tracked continuously to about 6 s,but the long period part is missing.The effect of S transform is better than that of phase match filter(PMF),and the combination of the two will get more ideal results.

引文

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