describe the location of a reflector.
First step: calculation of two-way zero-offset travel time in a true model:
Second step: reverse Eiconal's continuation of t0(x) with wrong velocity :
Third step: imaging from the condition
The reflection image in time section we receive after substitution is:
Time-to-depth migration in this situation is depth scaling with true velocity :
We see that depth scaling does not supply correct imaging, although the error is not big: it is proportional to .