## Moveout approximation for P waves in a homogeneous VTI medium

**Veronique Farra** and
**Ivan Psencik**
### Summary

We propose an alternative expression for the P-wave moveout approximation in
a VTI medium based on the weak-anisotropy approximation. The proposed formulae
are relatively simple, they yield highly accurate results for zero and far offsets.
First-order formulae depend on four parameters, two-way zero-offset traveltime
*T*_{0}
related to the vertical velocity α, the depth *H* of the reflector and
two weak-anisotropy (WA) parameters ε and δ. Very accurate
second-order formula is slightly more complicated and, in addition to the
mentioned parameters, depends on an additional parameter, *r*, the ratio
of the S- and P-wave velocities. Since the dependence of the moveout on
*r* is very weak, *r* can be specified as a typical S- to P-wave velocity
ratio and the number of parameters necessary for the specification of moveout
is four too.

### Whole paper

The paper is available in
PDF (106 kB).

In: Seismic Waves in Complex 3-D Structures, Report 22,
pp. 41-54, Dep. Geophys., Charles Univ., Prague, 2012.