利用改进的F-K变换法提取瑞雷波的频散曲线

发布时间：2018-04-19 08:35

本文选题：频散曲线 + F-K变换　；参考：《地球物理学进展》2017年01期

【摘要】：瑞雷波成像能够有效的探测近地表的横波速度结构,准确的提取瑞雷波的频散曲线是该技术的关键.F-K变换法是一种常见的提取频散曲线的方法,然而传统的F-K变换法由于受到震源频带范围和介质滤波作用的影响,计算的频散能量通常集中在较窄的频带范围内,其余频带的能量受到压制,因此提取出的频散曲线频带范围较窄,高阶模式不易识别,为了克服这种缺陷,我们提出一种改进的F-K变换法,提高了该方法提取高阶模式频散曲线的能力.在本文中,我们首先介绍了改进的F-K变换法的原理与计算步骤,然后分别利用传统的和改进的F-K变换法对理论模型正演模拟和实际采集的瑞雷波数据进行处理,将两种方法得到的频散能量图进行对比,结果表明改进的F-K变换法能够呈现出分辨率更高的频散信息,保证了高阶模式频散曲线的有效提取.
[Abstract]:Rayleigh wave imaging can effectively detect the velocity structure of shear wave near the surface. Accurate extraction of Rayleigh wave dispersion curve is the key of this technique. F-K transform is a common method to extract dispersion curve.However, because the traditional F-K transform method is affected by the range of the source frequency band and the filtering effect of the medium, the calculated dispersion energy is usually concentrated in the narrower frequency band, and the energy of the remaining frequency band is suppressed.Therefore, the frequency band range of the extracted dispersion curve is narrow and the high-order pattern is difficult to be recognized. In order to overcome this defect, we propose an improved F-K transform method, which improves the ability of this method to extract the high-order mode dispersion curve.In this paper, we first introduce the principle and calculation steps of the improved F-K transform method, and then use the traditional and improved F-K transform method to process the Rayleigh wave data from the forward simulation of the theoretical model and the actual collection, respectively.The results show that the improved F-K transform method can present higher resolution dispersion information and ensure the efficient extraction of high-order mode dispersion curves.
【作者单位】：长安大学地质工程与测绘学院;
【基金】：国家自然科学基金(41374145) 中国地质调查局地质调查项目(DD20160060)共同资助
【分类号】：P631.4

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