Conversion Points of Converted Wave in Vertical Inhomogeneous Media

Abstract

Calculating conversion points is a key problem in converted wave data processing. Here we introduce the methods to compute conversion point in vertical inhomogeneous media based on linear functions of velocity, or slowness with depth or vertical travel time. We also study three ways to choose appropriate equivalent velocity methods, including velocity fitting, travel time approximation and semblance coefficient methods. We compare the errors of the methods in vertical inhomogeneous media with asymptotic conversion point, Thomsen approximate formula and analytic formula in homogeneous media. The results show that conversion point would be calculated more accurately by the methods for inhomogeneous media.