Wavefield Extrapolation for Prestack Time Migration with Rms Velocity

A wave-equation based summation (WESUM) algorithm has been developed (Pan, 2006) for prestack depth migration with flexibility and option to output common image gathers in the offset domain. In this abstract we demonstrate the application of WESUM for prestack time migration (PSTM) with rms velocity as opposed to running usual wave equation migration (WEM) using interval velocity. Just as in Kirchhoff PSTM, at each individual image point, WESUM performs constant velocity migration so that it can be used to conduct velocity analysis. In addition, the WESUM uses real source and receiver locations and thus can handle 2D crooked line.