加权叠加法压制多次波

一个 CDP 道集经动校正后，多次波仍存在剩余时差δt，它随炮检距呈抛物线规律变化。由δt 的变化即可求出多次波剩余波数△k 的分布规律。据此，可设计一个理想的叠加复剩余波数响应，以菲涅尔(Fejer)多项式来逼近，求出各叠加道的加权系数，用于动校正后的 CDP 道集道的加权叠加。在 t-x 平面选择δt，即可改变叠加复剩余波数响应，从而改变各道的加权系数，实现最佳压制多次波的效果。

Multiple suppression with weighted stack method

After normal moveout (NMO) correction of a CDP gather, multiples have residual moveout 8t, which varies parabolically as a function of shot-receiver distance。The distribution of residual wave number Ok of multiple can be derived from the changes of 8t。Therefore, a desirable complex stacking residual response of wave number is designed, the weight of each stacked trace is derived with Fejer polynomial approximation and then the NMO corrected CDP gather is weighted stacked. The complex stacking residual response of wave number can be changed with the change of 8t on the t-x plane and there by the weight of each trace can also be changed to yield optimum results in suppressing multiples.