Forward modeling of wave equation and reverse-time migration in frequency domain with rugged topography based on generalized coordinate transformation
Effiicient and accurate forward modeling of wave equations is the key of seismic structure imaging and parameter inversion.The finite difference method in frequency domain offers notable advantages for forward modeling,including enhanced computational efficiency in multi-source simulations and greater flexibility in grid spacing selection.However,challenges arise in effectively addressing topographic surface conditions using this method.To tackle the issues associated with frequency domain wave-equation forward modeling and reverse time migration with rugged topography,we propose employing a generalized coordinate system.This approach involves utilizing a mapping from the traditional Cartesian coordinate system to an topographic coordinate system to accurately simulate the propagation of seismic wave fields.Building upon this framework,we further explore the feasibility of implementing frequency domain reverse time migration.We conduct numerical tests using both uniform and Foothills models to validate the effectiveness and computational efficiency of our proposed method.The results demonstrate that this approach offers a promising solution for forward modeling in frequency domain seismic imaging and inversion of complex surface environments.