Homogeneous medium

The procedure to estimate the elastic constants of a homogeneous TI medium from traveltime measurements near one axis of symmetry is the following:

1.

Fit the traveltimes with elliptically anisotropic models, one model for each wave type. This gives direct and NMO group slownesses.

2.

From the direct and NMO group slownesses, find the corresponding direct and NMO phase velocities, using equation (26).

3.

From the estimated phase velocities, find the elastic constants using the equations that correspond to the given recording geometry [either (22) or (23)]. In the case of SH waves, the estimated phase velocities squared are the same as the corresponding elastic constants.