相关速度谱和复数道相关速度谱

Correlation velocity spectrum and complextrace correlation velocity spectrum

依据平均振幅能量准则求得的叠加速度谱,分辨率往往较低,Neidell和Taner(1971)利用非归一化和归一化互相关准则制作了相关速度谱,使分辨率有了改进。但是在复杂地区,由于地震道的振幅随炮检距的增大而明显衰减,造成各道的波形不一致,这样使用相关速度谱也受到限制。在这种情况下,可采用复数道相关速度谱,它适用于波形有变化的相关处理,具有较强的抗干扰能力。在相关计算中,采用了幅角加权技术,进一步增强了相位的一致性,从而使速度能量更加集中。此法并不要求较高的覆盖次数。文中用具体实例说明复数道相关速度谱的效果。

Stacking-velocity spectrum obtained using average amplitude energy criterion usually has low resolution. Neidell and Taner made correlation velocity spectra using nonnormalized and normalized cross correlation criterions in 1971, and improved the resolution. Unfortunately, in the case of complex area, the application of correlation velocity spectrum may be limited by waveform nonuniformity caused because seismic amplitude greatly attenuates due to offset increase. In such a case, complextrace correlation velocity spectrum works,which is applicable to waveform-variable correlation processing and resists noise guite well. The application of argument weighting to the correlation calculation achieves strict homophase, making energy more concentrated. This method also works upon the seismic data which were collected using low mu- ltiplicity. The effectiveness of complex-trace correlation velocity spectrum is illustrated by examples.