Frequency-Domain qP Wave Simulation in TTI Media Using Weighted-Averaging Finite-Difference Operator

摘要

Finite-difference method is a widely applied seismic numerical simulation method. Finite-difference method accurately simulates the seismic wave propagation in any inhomogeneous media, but it has the problem of numerical dispersion. In order to decrease the numerical dispersion, many scholars do a lot of researches and present corresponding solving methods. Jo et al. (1996) present optimal 9-point weighted-averaging method solving the 2D acoustic equation in isotropic media. To improve the operator accuracy, Shin and Sohn (1998) designed a 25-point weighted-averaging operator at four different angles. Some scholars apply the optimal weighted-averaging finite-difference operator to frequency-domain forward modeling in isotropic media. Stekl and Pratt (1998) present 9-point finite-difference operator which calculate in rotated coordinate systems. Min et al (2000) propose a 25-point weighted-averaging scheme for 2-D elastic modeling in the frequency domain. On the basis of former scholars' research, we extend the frequency-domain finite-difference elastic modeling method in isotropic media, and present frequency-domain 25-point weighted-averaging finite-difference operator for qP wave simulation in transversely isotropic media with a tilted symmetry axis (TTI media). Using the 25-point weighted-averaging operator, we successfully simulate the qP wave propagation in homogeneous and layered TTI media.