Globally optimized Chebyshev Fourier propagator: A wide-angle dual-domain one-way method

We present a dual-domain one-way propagator using Chebyshev polynomials and global optimization. First, the square-root operator is approximated using Taylor expansion around the reference background velocity. Then, the first-kind Chebyshev polynomials are used to rearrange the partial derivative coefficients. Finally, the constant coefficients are optimized using simulating annealing by the globally-optimized scheme. We demonstrate the proposed method using theoretical error analyses and impulse responses. For various velocity contrasts, the accurate propagation angle of our method is about 60°, which allow us to handle wide-angle propagations and strong lateral velocity contrast simultaneously by purely using Fourier transform. Only four 2D Fourier transforms are required for each step of 3D wavefield extrapolation. Compared with globally optimized Fourier finite-difference method, this method has no splitting error for 3D cases and no numerical dispersion.