Stretch-free migration imaging condition

Prestack migration has angle-dependent wavelet stretch effects, which lowers the image resolution at large reflection angles. Most current stretch correction methods operate on the migrated images. We develop a new stretch-free imaging condition, which does a shrink-and-shift operation on the extracted propagation wavelet after extrapolation, but before the imaging condition is applied. The algorithm is illustrated with the excitation amplitude imaging condition; the new images show successful stretch corrections over wide angle apertures, and preserve amplitude and phase.