Translations:Mathematical foundation of 3-D migration/83/en

We start with the solution of the 3-D scalar wave equation to extrapolate a 3-D zero-offset wavefield P(x, y, z = 0, t) as given by equation (G-2) in the frequency-wavenumber domain. We also assume a horizontally layered earth model associated with a vertically varying velocity function v(z). By inverse Fourier transforming equation (G-2), we have