Traveltime Parameters for Vertically Heterogeneous 2D TTI Media

In this paper, we derive the traveltime parameters for 2D vertically heterogeneous transverse isotropic model with tilted axis of symmetry (TTI) model. We show that in case of one-way propagation there are two more traveltime parameters in additional to the standard ones (the vertical traveltime, the normal moveout velocity and the heterogeneity coefficient) such as reflection point sideslip and anti-symmetrical parameter. The comparison performed for synthetic multilayered TTI model shows that the effective TTI traveltime parameters are strongly affected by the tilt value. To illustrate the effect of tilt we compare the effective traveltime parameters for the VTI and TTI multilayered models. The most dramatical difference is observed for heterogeneity coefficient. We also compute the traveltimes for these models and denote significant difference due to the presence of tilt.