Translations:Synthetic seismogram without multiples/6/en

We suppose that the subsurface consists of many ideal layers, each of which has a two-way traveltime $\Delta t$. Let the top interface (the surface of the ground or water, as the case may be) be called interface 0, let the next interface down be interface 1, and so on, to the bottom interface N. Denote the reflection coefficient of interface n by ${\varepsilon }_{n}$. In practice, many of these interfaces will be nonexistent. Any nonexistent interface has the reflection coefficient 0. Normal incidence is assumed, so the source and receiver coincide. This source-receiver point is chosen as a point just below the surface, so it is just barely inside the top layer (Figure 5).