A 2-WAY PARABOLIC EQUATION FOR ELASTIC MEDIA

The parabolic equation (PE) method is extended to handle wave propagation and scattering in range-dependent elastic waveguides, which are approximated by a sequence of range-independent regions. The two-way elastic PE involves an efficient PE-based scattering method for computing reflected and transmitted fields at the vertical interfaces separating range-independent regions. The one-way elastic PE is used to propagate the outgoing and incoming fields through the range-independent regions with two-way range marching. In addition to providing the backscattered field, the two-way PE provides a correction to the outgoing field. The self-starter is generalized to handle a source in a solid layer.