The Bidirectionally Coupled Ray Tracing study () is used to compute ray trajectories that are affected by external fields. This study solves for all degrees of freedom related to rays using a Time-Dependent Solver. All other degrees of freedom are computed using a Stationary Solver. The two solvers are repeated using a For-End For loop so that a self-consistent solution is obtained, taking the bidirectional coupling between the propagating rays and stationary fields into account.