Complex polarization analysis based on windowed Hilbert transform and its application
基于加窗Hilbert变换的复偏振分析方法及其应用

The implying assumption of the traditional Hilbert transform is that the length of time series is infinite. Considering its actual limitation, a multi_taper method (MTM) is introduced into the Hilbert transform of three short_time series to construct a complex covariance matrix. Time_varying polarization parameters can be measured by computing the eigenvalues and eigenvectors of the covariance matrix analytically. Combining with the polarization characteristics of special wave types and the measured parameters of actual seismic data, some signals can be identified, and then be separated using some adaptive filters, such as linear-cosine function or Gaussian weighting function filters. Application example of actual three-component earthquake data demonstrates that this method can be used to identify and separate some special seismic responses with special polarization.