Automatic noise-removal/signal-removal based on general cross-validation thresholding in synchrosqueezed domain and its application on earthquake data
Automatic noise-removal/signal-removal based on general cross-validation thresholding in synchrosqueezed domain and its application on earthquake data
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DOI：
10.1190/geo2016-0433.1
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发表时间：
2017-07-01
期刊：
影响因子：
3.3
通讯作者：
Langston, Charles A.
中科院分区：
文献类型：
--
作者：
Mousavi, S. Mostafa;Langston, Charles A.
记录的地震信号经常被噪声破坏。本文提出了一种基于高分辨率时频分析的单道地震资料自动去噪方法。同步压缩是一种时频重排方法，其目的是锐化时频图像。噪声可以从信号中区分出来，并且在这个重新分配的域中更容易衰减。阈值水平是使用通用交叉验证方法估计的，该方法不依赖于有关噪声水平的任何先验知识。通过增加基于峰度测量的预处理步骤和基于自适应硬阈值的后处理步骤，提高了阈值化的效率。所提出的算法可以衰减噪声（白色或彩色）并保持信号或去除信号并保持噪声。因此，它可以用于正常的去噪应用或环境噪声研究中的预处理。我们测试了所提出的方法的性能合成，微震，地震地震图。
Recorded seismic signals are often corrupted by noise. We have developed an automatic noise-attenuation method for single-channel seismic data, based upon high-resolution time-frequency analysis. Synchrosqueezing is a time-frequency reassignment method aimed at sharpening a time-frequency picture. Noise can be distinguished from the signal and attenuated more easily in this reassigned domain. The threshold level is estimated using a general cross-validation approach that does not rely on any prior knowledge about the noise level. The efficiency of the thresholding has been improved by adding a preprocessing step based on kurtosis measurement and a postprocessing step based on adaptive hard thresholding. The proposed algorithm can either attenuate the noise (either white or colored) and keep the signal or remove the signal and keep the noise. Hence, it can be used in either normal denoising applications or preprocessing in ambient noise studies. We tested the performance of the proposed method on synthetic, microseismic, and earthquake seismograms.