广义S变换与短时傅里叶变换在地震时频分析中的对比研究

Contrastive Study of Generalized S Transform with Short-time Fourier Transform in Seismic Time-frequency Analysis

短时傅里叶变换(STFT)和广义S变换(GST)都被应用到地震时频分析中,但对两者在信号分析过程中的特点和差异的研究相对较少。通过比较两者的理论公式、窗口函数及地震信号的实际处理效果发现:短时傅里叶变换在地震信号分析过程中整个时频域具有相同的分辨率,整体性较强,缺少时频聚焦能力,不能对信号重点观测区域有针对性的提高时频分辨率;广义S变换对地震高频信号具有较高的时间分辨率,对低频信号具有较高的频率分辨率,且可以通过改变参数p的值对广义S变换窗口函数的形态做出较大的调整,也可以改变λ的值实现窗口形态微调,通过对窗口函数的调整,广义S变换可以对信号特定区域进行时频聚焦。

The short-time Fourier transform（STFT） and generalized S transform（GST） are all applied to the seismic time-frequency analysis procedure, but without systematic study of difference and peculiarity between the two in signal analysis procedure. The paper through correlation of theoretical formulae, window functions and real processed effects of the two has found that the STFT during the seismic signal analysis procedure has identical resolution in whole time-frequency domain with better integrity, but lack of time-frequency focusing capability and can not enhance time-frequency resolution in key signal observation area. The GST has higher time resolution on seismic high frequency signals, higher frequency resolution on low frequency signals; and can make major adjustment on GST window functions through change of parameter p; also can change λ value to realize fine adjustment of window configuration;through adjustment of window functions, GST can carry out time-frequency focusing in signal specific areas.