Optimized Staggered-grid FD Method for First-order Acoustic Equation Based on Exact Time Evolution Schemes

First-order acoustic-wave equations are widely used to carry out wave extrapolation in acoustic media with velocity and density variations. The Staggered Grid Finite-Difference (SGFD) method is one of the most popular ways to solve acoustic-wave equations. In order to improve computational accuracy both in time domain and space domain, we propose an optimized SGFD method for first-order wave equations based on exact time evolution schemes. Specifically, we utilize exact time-marching scheme to optimize SGFD coefficients in the wavenumber domain with least square method. The proposed approach ensures high accuracy in the time and space domain simultaneously, and it can be applied in reverse-time migration and waveform inversion.