基于互相关相移的主动源地震面波频散成像方法

发布时间：2018-04-02 16:42

本文选题：面波　切入点：相速度　出处：《地球物理学进展》2017年04期

【摘要】：以多道面波分析技术(MASW)为代表的主动源面波方法已经在地表勘探领域获得越来越多的应用.准确的面波相速度频散成像是利用主动源面波法进行近地表横波速度反演的必要条件.本文提出了一种新的主动源面波频散成像方法—CCPS(Cross-Correlation and Phase-Shifting)法.首先,将单炮面波记录由时空域变换到频率空间域并消去振幅谱的影响,得到归一化频谱.然后,依次将每道信号与整个记录进行互相关的同时进行相速度扫描叠加.最后经过一次求和过程即得到最终的频散图像.通过理论数据、实际工程地震面波资料和石油勘探面波资料比较了普通相移法和CCPS法的频散成像效果.研究表明:新方法相对于普通相移法而言,明显提高了频散图像的质量,相速度聚焦性能和背景噪声压制能力有显著改善.
[Abstract]:The active source surface wave method, represented by MASW, has been applied more and more in the field of surface exploration.Accurate surface wave phase velocity dispersion is a necessary condition for near-surface shear wave velocity inversion using active source surface wave method.In this paper, a new active source surface wave dispersion imaging method, CCPS Cross-Correlation and Phase-Shiftingmethod, is proposed.Firstly, the single shot surface wave record is transformed from space-time domain to frequency-space domain and the amplitude spectrum is eliminated, and the normalized spectrum is obtained.Then, each signal is cross-correlated with the whole record at the same time as phase velocity scanning superposition.Finally, the final dispersive image is obtained after a summation process.Based on the theoretical data, the seismic surface wave data of practical engineering and the surface wave data of petroleum exploration, the dispersive imaging effects of the ordinary phase shift method and the CCPS method are compared.The results show that the new method can improve the quality of dispersive images, improve the focusing performance of phase velocity and the suppression ability of background noise.
【作者单位】：中国石油大学(华东)地球科学与技术学院;
【基金】：国家自然科学基金(41374123)资助
【分类号】：P631.4

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