The autocorrelation of ambient noise is used to capture reflected waves for crustal and sedimentary structures. We applied autocorrelation to strong‐motion records to capture the reflected waves from sedimentary layers and used them for tuning the S‐wave velocity structure of these layers. Because a sedimentary‐layered structure is complicated and generates many reflected waves, it is important to identify the boundary layer from which the waves reflected. We used spectral whitening during autocorrelation analysis to capture the reflected waves from the seismic bedrock with an appropriate smoothing band, which controls the wave arrival from the desired layer boundary. The effect of whitening was confirmed by the undulation frequency observed in the transfer function of the sedimentary layers. After careful determination of parameters for spectral whitening, we applied data processing to the strong‐motion records observed at the stations in the Shimousa region of the Kanto Basin, Japan, to estimate the arrival times of the reflected waves. The arrival times of the reflected waves were found to be fast in the northern part of the Shimousa region and slow in the western and southern parts. These arrival times are consistent with those obtained using existing models. Because we observed a slight difference in the arrival times, the autocorrelation function at each station was used for tuning the S‐wave velocity structure model of the sedimentary layers using the inversion technique. The tuned models perfectly match the autocorrelation functions in terms of the arrival time of the reflected waves from the seismic bedrock.

中文翻译：

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利用强运动记录的自相关调整日本关东盆地下草地区深部沉积层的S波速度结构

环境噪声的自相关用于捕获地壳和沉积结构的反射波。我们对强运动记录应用了自相关，以捕获沉积层的反射波，并将其用于调整这些层的S波速度结构。由于沉积层结构很复杂并且会产生许多反射波，​​因此重要的是确定反射波的边界层。我们在自相关分析过程中使用了频谱增白技术，以适当的平滑带捕获了来自地震基岩的反射波，该平滑带控制了波从所需层边界到达的情况。在沉积层的传递函数中观察到的起伏频率证实了增白的效果。在仔细确定用于光谱增白的参数之后，我们将数据处理应用于在日本关东盆地下草地区观测站观测到的强运动记录，以估计反射波的到达时间。发现反射波的到达时间在Shimousa地区的北部较快，而在西部和南部较慢。这些到达时间与使用现有模型获得的时间一致。由于我们观察到了到达时间的微小差异，因此使用反演技术将每个站的自相关函数用于调整沉积层的S波速度结构模型。经过调谐的模型在地震基岩反射波的到达时间方面与自相关函数完全匹配。我们将数据处理应用于在日本关东盆地Shimousa地区各站观测到的强运动记录，以估计反射波的到达时间。发现反射波的到达时间在Shimousa地区的北部较快，而在西部和南部较慢。这些到达时间与使用现有模型获得的时间一致。由于我们观察到了到达时间的微小差异，因此使用反演技术将每个站的自相关函数用于调整沉积层的S波速度结构模型。经过调谐的模型在地震基岩反射波的到达时间方面与自相关函数完全匹配。我们将数据处理应用于在日本关东盆地Shimousa地区各站观测到的强运动记录，以估计反射波的到达时间。发现反射波的到达时间在Shimousa地区的北部较快，而在西部和南部则较慢。这些到达时间与使用现有模型获得的时间一致。由于我们观察到了到达时间的微小差异，因此使用反演技术将每个站的自相关函数用于调整沉积层的S波速度结构模型。经过调谐的模型在地震基岩反射波的到达时间方面与自相关函数完全匹配。