*3.4. Initial Velocity Model*

The interval velocity curve is extracted at the theoretical velocity model CDP 30 to simulate the data of a well. The layer velocity curve at CDP 30 is extrapolated under the paths constraint shown in Figure 10 to obtain a interval velocity model, as shown in Figure 11, which is consistent with the theoretical model shown in Figure 4. The vertical difference is because the theoretical velocity model is in depth domain and the extrapolation result is in time domain.

**Figure 11.** (**a**) Interval velocity curve at CDP 30; (**b**) extrapolation velocity result under the paths constraint.
