曲率放大的λ-f域高分辨率抛物Radon变换多次波压制方法

Multiple-suppression method using theλ―f domain high-resolution parabolic Radon transform with curvature magnification

在实际数据处理中抛物Radon变换是多次波压制的一种常用手段,然而,常规Radon变换方法难以有效压制那些与一次波曲率差异较小的多次波,本文给出了曲率放大的多次波压制方法来改善多次波的压制效果。通过研究影响同相轴的曲率的参数,发现压缩炮检距或增大时差能够放大多次波和一次波曲率差异,加大一次波和多次波在Radon域的分离程度,从而提高了多次波的压制能力。为进一步提高Radon变换的计算效率和精度,采用λ-f域高分辨率抛物Radon变换,通过引入新变量λ消除了常规Radon变换算子对频率的依赖性,由于变换算子和它的逆只需要计算一次,因此显著提高了计算效率。通过理论模型和实际资料的处理表明,该方法能够较好地压制表层多次波,对于那些与一次波存在一定曲率差异的层间多次波,也具备一定的压制能力。

In actual data processing,the parabolic Radon transform is a commonly used method to suppress multiples.However,it is difficult to suppress those multiples whose curvatures are very similar to that of the primaries using the conventional Radon transform.This paper gives a multiple-suppression method with curvature amplification to improve the multiple-suppression effect.By studying the parameters that affect the curvature of the event,it is found that compressing the offset or increasing the time difference can amplify the difference between the curvatures of the multiples and primaries,and the separation degrees of the multiples and primaries in the Radon domain are increased,so the multiple-suppression ability is improved.To improve the computational efficiency and accuracy of the Radon transform,theλ–f domain high-resolution parabolic Radon transform is used to eliminate the frequency dependence of the conventional Radon transform operator by introducing a new variableλ.Because the new transform operator and its inverse operator need to be calculated only once,the computational efficiency is significantly improved.The theoretical model data and the actual data processing show that the method can suppress the surface multiples well,and it also has a certain ability to suppress the internal multiples that have a particular curvature difference from the primaries.