Conclusions

We present a procedure for calculating ray-coordinate system updates incorporating RWE and phase-ray tracing. This procedure can successfully generate a ray-coordinate systems that better conforms with the direction of wavefield propagation. This fact then leads to an improved wavefield extrapolation operator fidelity. However, coordinate system realignment is not always a global advantage. This is because, as a result, structural dips may be mapped more steeply in the updated ray-coordinate velocity models. Importantly, steeper structural dip angles in the velocity model also inhibit the accuracy of wavefield extrapolation. Accordingly, we suggest that a trial-and-error (or a more sophisticated) approach could be used to generate a ray-coordinate system for RWE that represents an optimal trade-off between improving operator fidelity and lowering structural dips in resulting velocity models.