地震信号的复调制细化方法的频谱分析

Analysis of Seismic Signal Spectrum Based on ZFFT

为了得到地震信号某段频谱的精细结构,提高其频率分辨率,提出了频率细化技术。通过对地震信号进行复调制移频、数字低通滤波、重新采样、复FFT处理、频率调整实现对地震信号的复调制频率细化。利用Matlab对实际地震信号进行分析,得到地震信号能量最大处的频率,实现了准确、快速地对地震信号某一窄带频谱的分析和研究。与FFT相比,复调制细化得到的地震信号幅度最大处的频率更接近真实值,使地震信号的频谱更精确。

In order to get a certain fine structure of the seismic signal spectrum and improve the frequency resolution, this paper puts forward the frequency refining technology. Based on the ZFFT frequency shift, digital lowpass filter, resample, complex FFT processing and frequency adjustment, this paper successfully achieves the ZFFT of the seismic signal, which uses the Matlab to analyze the actual seismic signal and get the frequency of maximum energy of the seismic signal. It realizes accurately and rapidly to analyze and study a certain narrowband spectrum of the seismic signal. Compared to FFT, ZFFr makes the frequency of maximum amplitude of the seismic signalcloser to the true value and makes the signal spectrum more precise.