Linear‐transform techniques for analyzing shear‐wave splitting in four‐component seismic data

iUlUlU~ directions of faster and slower split shear-waves. The medium between the source and the first g-phone, and between successive geophones, is assumed to be homogeous Most techniques for analyzing shear-wave splitting employ with a uniform distribution of cracks. rotation procedures and tend to be computing intensive. We define the principal time series qSl(c) and @2(c) of the Here, we present a fast linear-transform technique for faster and slower split shear-waves, respectively, as the time analyzing shear-wave splitting in four-component seismic series received at a geophone position when a source vector data (two source orientations recorded by two receivers). F is polarized along el and e2, respectively, with signature We transform the data by four linear transforms so that the F(I). The concept of the principal time series was introduced shear-wave motion is linearized in a wide variety of by Alford (1986) and Thomsen (1988). Here, we give an conditions. Many properties of shear-waves can be easily alternative geometrical definition. We introduce two estimated from the transformed components. transformed time series vz(c) and m(c) as the sum and The technique allows various attributes to be measured, difference, respectively, of the principal time series qSl(c) and including the polarizations of faster split shear-wave, and the qs2(c): time delays between faster and slower split shear-waves, as well as allowing the time series of the faster and slower split wo = qSI(c) + qs2(c); shear-waves to be separated deterministically. In addition, with minimum assumptions, the geophone orientations can W) = qssl(c) qs2(c). (1)