Accuracy of common-azimuth migration approximations

Louis Vaillant and Biondo Biondi

louis@sep.stanford.edu, biondo@sep.stanford.edu

ABSTRACT

Common-azimuth migration (CAM) is an attractive solution for 3-D prestack imaging. It reduces the full 5-D phase-shift operator to 4-D through the stationary-phase approximation, lowering the computational cost. However, this assumption yields constraints in the downward-continuation process that can limit accuracy. Those errors are estimated in this paper by comparison to other wave-equation methods and to analytical solutions. Common-azimuth migration appears robust, but leaves opportunities for formulating an extended migration algorithm, which overcomes some of its inherent limits.