## Weak-anisotropy moveout approximations
for P waves in homogeneous TTI layers

**Ivan Psencik**
**&** **Veronique Farra**
### Abstract

We offer approximate nonhyperbolic P-wave moveout formulae
applicable to weakly or moderately anisotropic media of arbitrary
anisotropy. Instead of commonly used Taylor expansion of the square
of the reflection traveltime in terms of the square of the offset,
we expand the traveltime in terms of weak-anisotropy (WA) parameters.
We specify the general formulae for the TI media with arbitrary tilt
of the axis of symmetry. Resulting formulae depend on three WA
parameters specifying the TI symmetry and two angles specifying
the orientation of the axis of symmetry. Tests of the accuracy
of the more accurate of approximate formulae indicate that maximum
relative errors are not greater than 2.5% for P-wave anisotropy of,
approximately, 26%.

### Whole paper

The paper is available in
PDF (125 kB).

*Seismic Waves in Complex 3-D Structures*, **26** (2016), 61-80.