Dual extrapolation algorithms towards optimum efficiency and accuracy

Yanpeng Mi, Gary F. Margrave, Zhengsheng Yao

In heterogenous media with velocity field v(x,z), Fourier domain wavefield extrapolators are typically applied recursively over depth to perform migration or modelling. Due to the approximation in the theory, errors accumulate through depth steps. In this paper a dual algorithm is formulated that employs high-accuracy, integral, wavefield extrapolation to compute quality control wavefields at a grid coarser than the imaging grid and employs algorithms of lower accuracy to compute the intermediate wavefields.