Vice professor ZHANG Jinhai and his teacher YAO Zhenxing develop a method to reduce two-way splitting error of FFD method. They compensate the two-way splitting error in dual domains, alternately in the spatial and wavenumber domains via Fourier transform.

Numerical experiments show that optimized one-term compensation can achieve nearly perfect circular impulse responses and the propagation angle with less than 1% error for all azimuths is improved up to 60 from 35.  Compared with traditional single-domain methods, our scheme can handle lateral velocity variations (even for strong velocity contrasts) much more easily with only one additional Fourier transform based on the two-way splitting FFD method, which help retain the computational efficiency.

Zhang and Yao. Reducing two-way splitting error of FFD method in dual domains. Geophysics, 2011, 76, S165-S175. （Download Here）

Figure 5. Depth slices of 3D impulse responses at different dip angles.