The modified Snell law for seismic ray in anisotropic media

It is related to the application of Snell law to solute the geometrical parameters for seismic waves on the interface in various kinds of complicated media. Although the application of Snell law in isotropic media is well known, the classic Snell law based on the phase velocity is not easily adapted to anisotropic media and need to be modified because of the difference of the magnitude and direction between the phase velocity and ray velocity (energy velocity), which is important to the study of seismic behavior in anisotropic media. So far, few reports about it have been published. By starting from the