Azimut-Angle Migration for Node Type Data

Kirchhoff (or Born) migration- inversion formulas of full azimuth data in the azimuth-opening domain have been obtained as integrals over migration dips, azimuth and opening angle, making use of the Beylkin Jacobian that transforms the acquisition coordinates into the four angular coordinates. It happens that this determinant is quite simple and that the final imaging formula is also simple,for P-P and P-SVwaves. The interest of this approach is to form substacks for selected ranges of azimuth and incidence in order to conduct AVAZ studies. We show how to form such classes, introducing a definition always stable of the local dip dependant azimuth and demonstrate the validity of the formula on node type synthetic data. Application to a real node type dataset is also shown.