Specular ray parameter extraction and stationary‐phase migration

Abstract

The Kirchhoff‐type prestack depth migration operator is a diffraction stack of seismic reflection energies over seismic traces. Typically, the diffraction stack is carried out over the full data aperture, producing not only images of reflectors but also aliasing artifacts. Aliasing artifacts often break reflector continuity in images. The stationary‐phase approximation to the migration operator shows that, for image points on reflectors, traces within the neighborhood of specular rays contribute most to the diffraction stack. Traces outside this vicinity introduce aliasing artifacts into the image, especially in the case of coarse trace spacing and aperture truncation. A new migration algorithm, denoted as stationary‐phase migration, is proposed to find the specular ray parameters and then to migrate the specular‐ray energies and reject nonspecular ray energies to yield images with less aliasing.