If we have two waves with different apparent velocities that interfere with
each other, then it is reasonable to apply wave-field continuation into the
homogeneous model because these waves can be separated as a result of
propagation in a continued field. The consideration is very simple.
If both waves are
observed in the interval and the k-th one
has travel time ( see Figure a), then as the result of forward
continuation into the medium with velocity,
*v*_{c}<min{*v _{1}*,

The choice of velocity *v*_{c} does not depend on the velocity
in the true model of the medium, but only on the condition
of wave resolution. We have time resolution if
(where *T _{0}* is the duration of the pulse) and spatial
resolution if . It is very easy to derive
proper conditions in terms of

Let one of the waves be nondesirable (for example, one which has less value of
apparent velocity: *v _{2}* <

In fact, the operators act as fan filters for the fan of velocities

|*v*|>*v*_{c}.

In order to improve the quality of resolution, we can
introduce preliminary time shifts .Afterward waves have new apparent velocities and *v*'_{2} =*v*_{n}. Now we may apply the operator at *v*_{c}<*v*_{n}. The big advantage of this approach is that it
is not necessary that apparent velocities *v _{1}* and

The Figure illustrates interference analysis for the
situation when *V _{1}* changes in the interval (5 km/s, 6.3 km/s) and

1/13/1998