F-K域多尺度瑞雷面波全波形反演  

Multiscale Rayleigh wave full waveform inversion in F-K domain

作　　者：周云腾 张致付[1] ZHOU Yun-teng;ZHANG Zhi-fu(School of Geophysics and Information Technology,China University of Geosciences(Beijing),Beijing 100083,China;China Merchants Chongqing Communications Technology Research and Design Institute Company Limited,Chongqing 400067,China)

机构地区：[1]中国地质大学(北京)地球物理与信息技术学院,北京100083 [2]招商局重庆交通科研设计院有限公司,重庆400067

出　　处：《地球物理学进展》2020年第6期2309-2314,共6页Progress in Geophysics

基　　金：国家自然科学基金(41530321)资助。

摘　　要：瑞雷面波,又被称为地滚波,具有强能量和频散特性.面波对地下介质中横波速度十分敏感,利用面波测量浅层剪切波速度结构,已经在浅表勘探领域有了广泛的应用.本文研究瑞雷面波波场的F-K域全波形反演方法,成像近地表横波速度结构.首先对地震数据进行二维傅里叶变换至F-K域,以F-K域振幅谱数据构建目标函数,降低了面波波形反演的非线性;通过对目标函数的迭代求解,得到最优的反演速度模型.并且,采用从低频到高频的多尺度反演策略,减小了面波波形反演中对初始模型的依赖,缓解了周期跳跃的问题.为了验证本文方法的可行性,对水平层状模型、横向变速模型及异常体模型的横波速度结构反演,结果显示,F-K域面波波形反演方法能够有效的对近地表横波速度模型进行重构,得到高分辨率的近地表速度成像.Rayleigh wave, called ground-roll, is strong energy and dispersion characteristics. And it is sensitive to shear wave velocity in the shallow medium. Rayleigh wave data are acquired and processed to provide shear wave velocity structures, which help detect subsurface information about geologic structure and anomaly. In this paper, an alternative full waveform inversion of Rayleigh wave is studied in the F-K domain to image high resolution shear wave velocity structure. Full waveform data are transformed to F-K domain by 2 D FFT, and it’s amplitude spectrum is used to build the objective function, which can weaken the nonlinear of full waveform inversion. The objective function is optimized and iterative solutions are obtained. A multiscale inversion strategy, data filter from low to high frequency, is adopted to reduce dependence on initial model and mitigate cycle skipping. Some experiments on several typical geological models are made to verify the feasibility of the proposed method. Results illustrate that the F-K domain Rayleigh wave waveform inversion method can effectively reconstruct the high-resolution shallow shear wave velocity structure.

关 键 词：瑞雷面波 波形反演 F-K域 

分 类 号：P631[天文地球—地质矿产勘探]