高铁震源地震信号的挤压时频分析应用

The applications of synchrosqueezing time-frequency analysis in high-speed train induced seismic data processing

我国每天有数千趟高铁列车驰骋在纵横交错的高铁线路上,构成了十分理想的均布震源,但寻找适合高铁震源地震信号的处理方法是充分挖掘信息的关键.传统的频谱分析结果表明高铁震源所产生的地震信号具有明显的窄带分立谱特征,但无法精确获得高铁震源地震信号的时频变化规律.本文首次将挤压时频分析这种分析工具引入到高铁震源地震信号处理中,对中国南方某高铁沿线采集到的高铁震源地震数据进行了分析.处理结果表明:利用挤压时频分析能够更加精确地刻画频率成分随时间的变化,能够利用单检波器精确刻画高铁列车的运行状态(匀速、加速等);同时利用挤压时频变换还可高精度地重构出所需频带的信号,为提取高铁震源地震信号的特征成分提供了一种有力工具.

In China,there are thousands of high-speed trains running on high-speed railway every day.How to choose some suitable processing methods is critical to explore useful information.The classical spectrum analysis has shown the amplitude spectrum of high-speed train induced seismic data has a multi-narrow-band characteristic.However,the conventional spectrum analysis cannot characterize the time-frequency characteristics of high-speed train induced seismic data with high precision.In this paper,we introduce the synchrosqueezing time-frequency analysis to high-speed train induced seismic data for the first time and apply this tool to the high-speed train induced seismic data which is acquired by Peking University in southern China.The data processing results show some advantages of the synchrosqueezing time-frequency analysis.The synchrosqueezing time-frequency analysis not only can depict the time-frequency characteristic more precisely but also can characterize the running state of one high-speed train,such as acceleration.Besides,the synchrosqueezing time-frequency transform can also be used to reconstruct the signal within a specified frequency band,which is very useful to extract the characteristic component of the high-speed train induced data.