When the migration velocity is correct and the image is focused at zero subsurface offset, the transformation to angle domain does not change the depth of the image point, and the reflections are imaged at the same depth for all aperture angles. In contrast, when the reflections are not focused at zero offset, the transformation to the angle-domain maps the events at different depths for each different angle. The variability of the depth with the aperture angle is described by the RMO function, which we want to measure and quantify as a function of the perturbation in anisotropic parameters encountered along the propagation paths.

4/6/2006