精密控制机械震源特征及信号检测方法

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

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。

Based on the different characteristics of the conventional vibroseis with accurately controlled routinely operated sig- nal system（ACROSS）, the ACROSS signal was processed by the cross-correlation, short-window correlation, cross-coher- ence 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 char- acterized by good stability of processing results and can highlight the high-energy frequency components, but it is not applica- ble for analysis of the narrow frequency band signal with much difference in power spectral characteristics. There is an over- lap 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.