一种适用于有限长度混合相位未知脉冲的最小平方反褶积新方法

A new least-squares deconvolution method for unknown finite length mixed-phase pulse

普通的最小平方反褶积只有在子波为最小相位脉冲和反射序列为白噪声的假设下才是成立的,而对于混合相位未知脉冲来说,这种最小平方反褶积就不再适用了。本文提出一种适合于有限长度混合相位未知脉冲的最小平方反褶积方法。运用此法只需预先估计一个混合相位子波的长度。合成数据的试验结果表明,该方法有较好的效果,且对预先估计出的子波长度不敏感。文中还证明混合相位未知脉冲最小平方反褶积等效于一种有间隙的平滑误差滤波器的作用,而这种有间隙的平滑误差滤波又可分解为一个前向多步预测误差滤波与一个后向多步预测误差滤波之和。可以预计这种新的反滤积方法将在地震数据处理中得到有效的应用。

Conventional least-squares deconvolution technique is valid only when the conditions of both minimum-phase wavelet and a white re- flectivity series are satisfied;but it is invalid in the case of unknown mixed-phase pulse.A new least-squares deconvolution method suitable for unknown finite duration mixed-phase pulse is proposed here.The predicted duration of a mixed-phase wavelet must be offered before the method is used.The tests of synthetic data show that this method bri- ngs good result and is insensitive to the predicted wavelet duration. It is also proved that the least-squares deconvolution method for un- known mixed-phase pulse is equivalent to gapped smoothing error filter- ing,which can be decomposed into a forward multi-step prediction error filtering and a backward multi-step prediction error filtering.It can be foreseen that this new deconvolution technique will finds its practical applications in seismic data processing.