GLOBALLY OPTIMIZED FOURIER FINITE-DIFFERENCE MIGRATION METHOD

Summary To accurately image complex structures with strong lateral velocity variations and steep dips, we develop a globally optimized Fourier finite-difference method that uses a rational approximation of the square-root operator in the one-way wave equation. The method uses a split-step Fourier operator coupled with a one-term optimized finite-difference operator. The two coefficients in the rational approximation are obtained by an optimization scheme that maximizes the maximum dip angle of the method for a given model. Our optimized method uses the same coefficients throughout a model in contrast