** Next:** Behavior of the reflection
** Up:** Tisserant and Biondi: 3-D
** Previous:** Construction

We verify our theoretical results on a model with five slanted planes
Vaillant and Biondi (2000).
The velocity function is *v*(*z*)=1.5+.5*z* km/s. The velocity
gradient allows us to highlight the rotation of the reflection azimuth
due to ray-bending.
The model consists of five planes
with 0, 15, 30, 45,60 dip and a 45 azimuth.
The dataset is migrated with full prestack migration.
We migrate first with the correct velocity
and then with a velocity that is too slow.
The migrated model is then transformed from offset to angle for
different reflection azimuths. Hence the image
has five dimensions: in-line and cross-line midpoints, depth,
aperture and reflection azimuth.
We select one midpoint and obtain a cube of a midpoint gather
sorted in aperture angle and reflection azimuth angle.