Computing pseudo-shear-wave data using PP and PS-wave traveltime interferometry in the rayparameter domain

Raul Cova and Kris Innanen

ABSTRACT

The kinematics of converted-waves is one the features that complicates the processing of multicomponent data. The asymmetry of the converted-wave raypath prevents us from using an important part of the methods developed for P-wave processing. To accommodate the issue of asymmetric raypath Grechka and Tsvankin (2002) and Grechka and Dewangan (2003) proposed what they named the PP+PS=SS method. Their goal was to generate pseudo-shear-wave data by convolution and correlation of PP and PS-wave data. By taking advantage of the shared raypath between PS and PP data in the space domain they were able to retrieve the kinematics of pure shear-wave data. Here, we propose moving the data to the plane-wave domain, where the shared features of PS and PP are more evident. Although the P and S-leg of converted-wave events may follow different raypath angles, they share the same rayparameter following Snell's law. Recently, Tao and Sen (2013) developed a mathematical framework for doing interferometry in the plane-wave domain. They showed how the cross correlation-type reciprocity equation holds for data in the rayparameter domain. Hence, data with shared rayparameters can be cross correlated to compute redatumed data. In this work I will be using seismic interferometry in the plane-wave domain to extend the PP+PS=SS method to this framework. Access to the rayparameter values will be achieved by the t-p transform and cross correlation and convolution of PS and PP data will be performed to reconstruct the kinematics of pure S-wave data.

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