Appendix A: Reflection and Transmission Coefficients
In this appendix, we provide the formulas for the amplitude-normalized plane-wave reflection and transmission coefficients, as derived in Červený et al. (1977) and Červený (2001) on the basis of the boundary conditions of Zoeppritz (1919). We assume the incidence angle to be between 0° and 90° or between 90° and 180°, depending on the direction that is chosen for the normal vector of the interface. In this appendix, we denote the incidence angle of a P-wave by θ and the incidence angle of an S-wave by φ.
We also state several linearized expressions for the reflection coefficients because generally, contrasts at seismic reflectors are rather small. The linearized formulas have proved to be very useful when we are inverting the reflection coefficients for medium parameters.