多道面波频散分析在实际大炮数据中的应用

通常应用小道距、短排列接收到的高频面波进行面波反演，但也已开始利用大炮地震数据中的面波进行近地表结构反演。复杂实际地震数据会降低频散曲线的精度，从而影响近地表结构反演的效果。文中探讨了大炮数据多道面波反演中如何确定参与频散分析数据道的最小炮检距大小、数据道数量及同炮地震数据中强弱面波不均衡等难题，提出了提高频散曲线生成精度的方法。实例分析结果证明这些提高频散曲线生成精度的方法是有效的，取得了令人满意的近地表结构反演效果。

Frequency dispersion analysis of MASW in real seismic data

Usually surface inversion is performed with the high-frequency surface wave acquired with small trace interval at short spreads.Near-surface structure inversion is also conducted with surface waves from surface seismic data.Real seismic data decrease the accuracy of frequency dispersion curve during the surface wave inversion due to data complexity,which will affect the results of near-surface structure inversion.In this paper,the authors make a detailed analysis about some difficulties of frequency dispersion analysis during the multi-trace analysis of surface wave (MASW),for example,how to determine the minimum offset and the quantity of seismic traces used for frequency dispersion analysis,and how to process strong surface waves and weak surface waves on the same shot data.At the same time,some discussions are made about frequency dispersion curve accuracy improvement.Analysis results on real data prove that our method is effective and can achieve favorable near-surface structure inversion results.