3D generalized nonhyperboloidal moveout approximation

Layered orthorhombic model

We also test the accuracy of the proposed approximation in a three-layer orthorhombic model over flat reflector with parameters (Layer 1-3) listed in Table 1. The thicknesses of the three layers are 0.25, 0.45, and 0.3 $km$ respectively. For previously proposed approximations, the effective coefficients are calculated, as the original authors suggested, by the VTI averaging relationship (Tsvankin and Thomsen, 1994; Hake et al., 1984). The reference rays for the proposed approximation (equation 1) were shot at $P_{x1} = 0.254$ and $P_{y1}=0.0$ along $x$ -axis, at $P_{x2} = 0$ and $P_{y2}=0.24$ along $y$ -axis, at $P_{x3}=0.195$ and $P_{y3}=0.166$ along $x=y$ , and at $P_{x4}=0.21$ and $P_{y4}=-0.182$ along $x=-y$ . The proposed generalized approximation performs with the highest accuracy (Figure 4).