3D MULTIVALUED TRAVEL-TIME AND AMPLITUDE MAPS

An algorithm for computing multivalued maps for travel time, amplitude and any other ray related variable in 3D smooth velocity models is pr esented. It is based on the construction of successive isochrons by tr acing a uniformly dense discrete set of rays by fixed travel-time step s. Ray tracing is based on Hamiltonian formulation and includes comput ation of paraxial matrices. A ray density criterion ensures uniform ra y density along isochrons over the entire ray field including caustics . Applications to complex models are shown.