一种减少偏移画弧的方法──同相叠加

在地震记录中的同-CDP道集内，有效波与干扰波在视速度、频率和振幅方面存在差异，主要表现为相邻地震记录道的相似性及振幅级别的变化。因此，应该设法选择相关性最好、振幅差值最小及振幅平均值适中的地震记录道进行盈前同相叠加，以消除地震叠加剖面中存在的局部干扰，减少非相干记录道对有致信号的干涉，使叠加效应最佳；同时计算某一时刻记录的振幅平均值，并根据其大小对CDP道集中记录道的野值进行剔除，从而提高地震剖面的信噪比，减少们移“画弧”现象。实际资料应用表明，该方法不仅能减少倍移“画弧”现象，而且在消除特殊的多次波方面也有明显效果。

In-phase stacking: a method to reduce arc phenomenon in seismic migration

In a CDP seismic trace gather, effective wave is different from noise wave in apparent velocity, frequency and amplitude. The main difference exists in similarity and amplitude variation of adjacent traces- The seismic traces which have optimal correlation, minimum amplitude difference and appropriate average amplitude are inphasely stacked to remove local noises in stacked seismic section and to reduce interference of incoherent traces with effective signals, achieving optimal stacking effect. In addition, average amplitude at a time is estimated, and it is taken as a standard value to elinimate wild value in a CDP trace gather, thus reducing arc phenomenon in seismic migration, and improving the signal/noise ratio of seismic section. It is shown in real data processing that the method not only reduces arc phenomenon in migration but also removes particular multiple reflection wave.