小波分析在微地震信号处理中的应用研究

摘要

We selected an appropriate wavelet basis for the processing of micro-seismic signal by investigating the characteristics of some wavelet bases. We also addressed the process of employing the wavelet toolbox in MATLAB to perform the processing of the measured micro-seismic signal. Sym8 wavelet basis, the heuristic threshold selection rule, soft threshold function and five-layer decomposition were employed to automatically suppress signal noise, which was shown to have better noise suppression effect. We drew a frequency-time wavelet coefficients chart and time-frequency spectrum (TFS) by scale-frequency conversion, which provided an effective approach for analyzing the characteristic of signal time and frequency synchronization.%通过探究小波分析特性选取适合微地震信号处理的基本小波,并以实测微地震信号为例,论述了利用MATLAB小波工具箱成功实现微地震信号处理的过程.利用对称小波函数sym8、启发式阈值选择规则、软阈值函数、5层分解等参数实现了信号的自动去噪,经检验去噪效果良好.通过尺度-频率转换成功绘制出频率-时间-小波系数图和时间频率谱,为分析信号时频同步特性提供了有效手段.