滤波在地震分析中的应用

本文运用MATLAB数字信号处理中的快速Fourier变换，对青海湟源地震台记录的云南大姚6．1级地震的P波和LG波进行频谱分析，找出其优势频率及衰减情况；根据爆破频率、噪声干扰频率和地震频率的不同，运用MATLAB滤波技术设计了Butterworth型低通数字滤波器、Butterworth型高通数字滤波器和Chebyshev Ⅰ型带通数字滤波器，对库尔勒台的爆破和地震叠加记录做滤炮处理，对湟源台记录的民乐—山丹两个余震进行噪声干扰滤波，爆破、噪声干扰经过滤波器合理滤波后，可以清晰地反映出地震波的真实信息，从而提高台站震相分析和地震波基础理论研究的准确性。

The Application of Filtering in Earthquake Analysis

This article makes use of the fast Fourier transformation in dealing with MATLAB digital signals to carry out spectrum analysis of the P wave and LG wave of the earthquake of magnitude 6.1 in Dayao, Yunnan and finds out its advantage frequency and attenuation. According to different blasting frequency, noise jamming frequency and earthquake frequency, with MATLAB filter technique, the Butterworth type low open digital wave filter, the Butterworth high pass digital wave filter and the Chebyshev I type band-pass digital wave filter were designed to triter the records of the Masting and the superimposition at Kuerle station and the noise jamming of the Minle-Shandan aftershocks recorded by Huangyuan station. After the fiflter of the blasting and the noise jamming, the true information of the seismic wave was clearly reflected, thus improving the accuracy of seismic phase analysis and the basic theoretical research of seismic wave.