Comparison of travel time computation and ray tracing methods
Bernard K. Law, Daniel O. Trad
Travel times and ray paths of the propagation of seismic body wave in heterogenous media are used in seismic tomography, imaging and inversion processes. In this study, we review the seismic ray theory, basic principles of the fast marching, wavefront construction and paraxial method. We analyze their differences and similarities to investigate the effectiveness of these methods in refraction tomography and seismic imaging. We compare the travel times from these method to a finite difference synthetic shot record of the Marmousi model and find travel time from all three methods are accurate except at area where rays diverge. We also used the travel time from the fast marching method in the refraction tomography processing of the Hussar 2D dataset. The CDP stack from the refraction tomography processing is more coherent and better resolved than the CDP stack with datum static correction only.