精密控制机械震源特征及信号检测方法

基于精密控制机械震源(ACROSS)信号与石油工业上的常规可控震源的特征差异,对ACROSS信号进行互相关、短时相关、相干和反褶积等四种方法处理分析,并分别从重复性、走时剖面、频谱特征以及信噪比等方面对处理结果进行对比分析研究。结果表明:互相关方法处理结果稳定性好,能较好地突出高能量频率成分,但不适用于在频谱特征里能量相差较大的窄带信号分析;ACROSS信号与环境背景噪声在频谱上有重叠,短时相关法会放大噪声的作用,其效果较相干和反褶积法显得略差一些;信噪比对相干和反褶积法处理结果的稳定性影响较大,相干和反褶积法适合于具有一定信噪比的ACROSS信号检测分析。

Characteristics and signal detection method of accurately controlled routinely operated signal system

Based on the different characteristics of the conventional vibroseis with accurately controlled routinely operated signal system(ACROSS), the ACROSS signal was processed by the cross-correlation, short-window correlation, cross-coherence and deconvolution. The comparative analysis on the processing results was carried out from repeatability, travel time profile, spectral characteristics, and signal-to-noise ratio (SNR). The results show that the cross-correlation method is characterized by good stability of processing results and can highlight the high-energy frequency components, but it is not applicable for analysis of the narrow frequency band signal with much difference in power spectral characteristics. There is an overlap in the spectrum of ACROSS signal and the ambient background noise. Short-window correlation can enlarge the role of the noise, and the effect of the processing is less than cross-coherence and deconvolution. The SNR has a great impact on the processing results of cross-coherence and deconvolution. The cross-coherence and deconvolution method are suitable for ACROSS signal detection with a certain SNR.