Rayleigh Wave Suppression Using Super-virtual Interferometry Method

WANG Yuhang, AN Shengpei, WANG Weizhong, HU Tianyue†

ACTA Scientiarum Naturalium Universitatis Pekinensis - - Contents -

Department of Geophysics, School of Earth and Space Sciences, Peking University, Beijing 100871; † Corresponding author, E- mail: tianyue@pku.edu.cn

Abstract Conventional Rayleigh wave suppression methods take advantage of differences in frequencies or apparent velocities between surface waves and effective waves to separate Rayleigh waves. However, the suppression may fail when the waves present small differences. To solve this problem, the super-virtual interferometry method is introduced to predict and suppress Rayleigh waves. It is a data-driven method, which is independent of frequencies or apparent velocities, and presents good applicability to complex near surface. Compared with conventional interferometry method which only predicts inter- receiver Rayleigh waves and requires a real shot around the receiver position, the super-virtual interferometry method is able to achieve shot-receiver Rayleigh waves, followed by adaptive subtraction using multichannel L1- norm. The synthetic data examples demonstrate the validity of the proposed method and obtain good results. Key words Rayleigh wave; super-virtual interferometry method; adaptive subtraction;

面波, 又称为地滚波。在地震勘探领域, 面波主要是瑞利波, 由 P 波和 SV 波耦合而成, 在自由表面传播, 振幅随深度呈指数衰减。瑞利波是地震干扰波的一种, 具有高振幅、低频率、低视速度及强频散等特点, 在地震记录中呈扇形分布, 与有效波信号重叠, 降低地震数据的信噪比, 增加了地震资料处理的难度。利用其特点, 已经有数种方法实

[ 1] [ 2]现对瑞利波的压制, 如高通滤波 、f- k 滤波 、

[ 3] [ 4 5] Radon 变换 等方法, 后又引入小波变换 、Rid- L1- norm

[ 6] [ 7] gelet 变换 、Curvelet 变换 等方法。以上 6 种方法都用不同的变换方法把原数据变换到另一个域,利用瑞利波与有效波在新的域分离的特性实现滤波。高通滤波是频率域滤波, 去除的是低频部分,可能会损伤部分低频有效波信号。f-k 滤波将数据转换到二维 f- k 域(频率 波数域), 但需要规则的空间采样间隔, 同时也存在分离不完全的问题。Radon变换分为线性 Radon 变换、抛物线 Radon 变换和双曲线 Radon 变换等。与 f- k 滤波类似, 对于地质

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