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(Fast Fourier Transtorm)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、快速的对地震信号某一窄带频谱的分析和研究.与FFT相比,复调制细化能够更好的得到幅度最大处的频率,使地震信号的频谱更精确.

In order to get a certain fine structure of seismic signal spectrum and improve the frequency resolution, the frequency refining technology is put forward. The ZFFT of the seismic signal is implemented by the ZFFT frequency shift, digital lowpass filter, resampling , complex FFT processing and frequency adjustment. Matlab is used to analyze the actual seismic signal to get the maximum frequency of the seismic signal energy, which relizes to analyze and study a certain narrowband spectrum of the seismic signal accurately and rapidly. Compared wiyh FFT, ZFFT is a more effective way to analyze local frequency structure of the seismic signal in terms of analysis accuracy.