ABSTRACT Identification of different modes of Rayleigh waves is essential in surface‐wave surveys. Multi‐mode Rayleigh waves can provide higher accuracy of the near‐surface structure than the fundamental mode alone. However, some modes or frequencies of Rayleigh waves may be absent in the vertical‐component seismic data. To complement the dispersion information, a method based on complex‐vector seismic data is proposed. We construct the complex vector by setting the radial component and vertical component as the real part and imaginary part, respectively. Then, high‐resolution linear Radon transform is used to obtain the multi‐mode Rayleigh‐wave dispersion image of the complex‐vector seismic data. Based on different dispersion characteristics of the radial and vertical components, the dispersion images of the complex–vector seismic data show better performance against interferences and mode misidentification. Synthetic and field examples demonstrate advantages of the complex‐vector method over the traditional vertical‐component method in spectral bands and dispersion curve mode identification. Therefore, a more robust and accurate near‐surface S‐wave velocity structure can be expected compared to the traditional vertical‐component Rayleigh‐wave method.

中文翻译：

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使用复矢量地震数据进行瑞利波频散分析

摘要 瑞利波不同模式的识别在面波测量中是必不可少的。与单独的基模相比，多模瑞利波可以提供更高的近地表结构精度。然而，在垂直分量地震数据中可能不存在瑞利波的某些模式或频率。为了补充频散信息，提出了一种基于复矢量地震数据的方法。我们通过将径向分量和垂直分量分别设置为实部和虚部来构造复向量。然后，使用高分辨率线性Radon变换获得复矢量地震数据的多模瑞利波色散图像。基于径向分量和垂直分量的不同色散特性，复矢量地震数据的频散图像显示出更好的抗干扰和模式错误识别性能。合成和现场示​​例证明了复矢量方法在光谱带和色散曲线模式识别方面优于传统的垂直分量方法。因此，与传统的垂直分量瑞利波方法相比，可以预期更稳健和准确的近地表 S 波速度结构。