Accurate and efficient numerical wave propagation in variable velocity media is crucial for seismic modeling and seismic migration,
particularly for reverse-time migration.
The FFD technique proposed in this paper promises higher accuracy than that of the conventional, explicit finite-difference method,
at the cost of only one forward and inverse Fast Fourier Transform.
Results in synthetic isotropic and anisotropic models illustrate FFD's stability in complicated velocity models.
The method can be used in reverse-time migration to enhance its accuracy and stability.