Interferometric imaging condition for wave-equation migration

Conclusions

We extend the conventional seismic imaging condition based on wavefield cross-correlations to achieve statistical stability for models with rapid, small-scale velocity variation. We assume that the random velocity variations on a scale comparable with the seismic wavelength are modeled by correlated Gaussian distributions. Our proposed interferometric imaging condition achieves statistical stability by applying conventional imaging to the Wigner distribution functions of the reconstructed seismic wavefields. The interferometric imaging condition is a natural extension of the cross-correlation imaging condition and adds minimally to the cost of migration. The main characteristic of the method is that it operates on extrapolated wavefields at image positions (thus the name interferometric imaging condition), in contrast with costlier alternative approaches using interferometry parametrized as a function of receiver coordinates.