|Seismic wave extrapolation using lowrank symbol approximation|
We have presented a novel algorithm for wave extrapolation in heterogeneous and anisotropic media. The algorithm is based on a lowrank approximation of the extrapolation symbol. It reduces the cost of extrapolation to that of a small number of FFT operations per time step, which correspond to the approximation rank. The algorithm has a high, spectral accuracy. In that sense, it is comparable with a number of other recently proposed FFT-based methods. Its advantage is a direct control on the accuracy-efficiency trade-off by controlling the rank of the approximation and the corresponding approximation error. We propose to incorporate the lowrank extrapolation algorithm in seismic imaging by reverse-time migration.