Shear wave imaging from traffic noise using seismic interferometry by cross-coherence
Shear wave imaging from traffic noise using seismic interferometry by cross-coherence
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DOI：
10.1190/geo2010-0188.1
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发表时间：
2011-11-01
期刊：
影响因子：
3.3
通讯作者：
Matsuoka, Toshifumi
中科院分区：
文献类型：
--
作者：
Nakata, Norimitsu;Snieder, Roel;Matsuoka, Toshifumi
将互相干法应用于公路和铁路交通噪声的地震干涉测量，以求取体波和面波。在存在高变量和强加性随机噪声的情况下，我们的首选算法使用交叉相干，它使用通过每个道的频谱幅度进行归一化，而不是互相关或去卷积。这种归一化抑制了加性噪声的影响，并克服了输入道之间的幅度变化引起的问题。该方法只利用信号的相位信息，忽略幅度信息，有效地从提取的响应中去掉了源特征，即使在强噪声的情况下也能得到稳定的结构重建。当原始道之间的相对幅度在道与道之间变化很大时，该算法特别有效。我们使用从交通噪声数据中提取的反射横波来构建叠加和偏移图像，并且使用提取的面波(Love波)来估计作为深度的函数的剪切速度。这一剖面与由地震干涉法构造的反射横波正常时差得到的层速度吻合得很好。这些结果在适用于地球物理和土木工程的广泛情况下都是有用的。
We apply the cross-coherence method to the seismic interferometry of traffic noise, which originates from roads and railways, to retrieve both body waves and surface-waves. Our preferred algorithm in the presence of highly variable and strong additive random noise uses cross-coherence, which uses normalization by the spectral amplitude of each of the traces, rather than crosscorrelation or deconvolution. This normalization suppresses the influence of additive noise and overcomes problems resulting from amplitude variations among input traces. By using only the phase information and ignoring amplitude information, the method effectively removes the source signature from the extracted response and yields a stable structural reconstruction even in the presence of strong noise. This algorithm is particularly effective where the relative amplitude among the original traces is highly variable from trace to trace. We use the extracted, reflected shear waves from the traffic noise data to construct a stacked and migrated image, and we use the extracted surface-waves (Love waves) to estimate the shear velocity as a function of depth. This profile agrees well with the interval velocity obtained from the normal moveout of the reflected shear waves constructed by seismic interferometry. These results are useful in a wide range of situations applicable to both geophysics and civil engineering.