3d Acoustic Prestack Reverse‐time Migration1

A prestack reverse‐time migration algorithm which operates on common‐source gathers, recorded at the Earth's surface, from 3D structures, is conceived, implemented and tested. Reverse‐time extrapolation of the recorded wavefield (a boundary‐value problem), and computation of the excitation‐time imaging condition for each point in a 3D volume (an initial‐value problem), are both performed using a second‐order finite‐difference solution of the full 3D scalar wave equation. The algorithm is illustrated by processing synthetic data for a point diffractor, an oblique wedge, and the French double dome and fault model.