Figure 4.
(a) Horizontally layered medium with two high-velocity layers. (b) Numerically modelled reflection response R(s1, x3, R, τ) at the surface. The horizontal slowness s1 = 1/2800 s m−1 is chosen such that the wave field is evanescent in the high-velocity layers. (c) Numerically modelled focusing function |$f(s_1,x_3,x_{3,R},\tau )$|. The trace at x3, R = 0 m illustrates the focusing condition of eq. (43).
