【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.更多还原

【Abstract】 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.更多还原