@article{DialloKuleshHolschneideretal.2006, author = {Diallo, Mamadou Sanou and Kulesh, Michail and Holschneider, Matthias and Scherbaum, Frank and Adler, Frank}, title = {Characterization of polarization attributes of seismic waves using continuous wavelet transforms}, issn = {0016-8033}, doi = {10.1190/1.2194511}, year = {2006}, abstract = {Complex-trace analysis is the method of choice for analyzing polarized data. Because particle motion can be represented by instantaneous attributes that show distinct features for waves of different polarization characteristics, it can be used to separate and characterize these waves. Traditional methods of complex-trace analysis only give the instantaneous attributes as a function of time or frequency. However. for transient wave types or seismic events that overlap in time, an estimate of the polarization parameters requires analysis of the time-frequency dependence of these attributes. We propose a method to map instantaneous polarization attributes of seismic signals in the wavelet domain and explicitly relate these attributes with the wavelet-transform coefficients of the analyzed signal. We compare our method with traditional complex-trace analysis using numerical examples. An advantage of our method is its possibility of performing the complete wave-mode separation/ filtering process in the wavelet domain and its ability to provide the frequency dependence of ellipticity, which contains important information on the subsurface structure. Furthermore, using 2-C synthetic and real seismic shot gathers, we show how to use the method to separate different wave types and identify zones of interfering wave modes}, language = {en} } @article{DialloKuleshHolschneideretal.2006, author = {Diallo, Mamadou Sanou and Kulesh, Michail and Holschneider, Matthias and Kurennaya, Kristina and Scherbaum, Frank}, title = {Instantaneous polarization attributes based on an adaptive approximate covariance method}, series = {Geophysics}, volume = {71}, journal = {Geophysics}, number = {5}, publisher = {SEG}, address = {Tulsa}, issn = {0016-8033}, doi = {10.1190/1.2227522}, pages = {V99 -- V104}, year = {2006}, abstract = {We introduce a method for computing instantaneous-polarization attributes from multicomponent signals. This is an improvement on the standard covariance method (SCM) because it does not depend on the window size used to compute the standard covariance matrix. We overcome the window-size problem by deriving an approximate analytical formula for the cross-energy matrix in which we automatically and adaptively determine the time window. The proposed method uses polarization analysis as applied to multicomponent seismic by waveform separation and filtering.}, language = {en} }