Variation of reflection coefficient is the primary thing in analyzing AVO. It starts when the P-Waves hit the interface, if it is normal incidence ([[:File:Fig.2.normal incidence.jpg|Figure 2]]), the coefficient reflections will be the difference of acoustic impedance (product of density and P velocity) over the sum. | Variation of reflection coefficient is the primary thing in analyzing AVO. It starts when the P-Waves hit the interface, if it is normal incidence ([[:File:Fig.2.normal incidence.jpg|Figure 2]]), the coefficient reflections will be the difference of acoustic impedance (product of density and P velocity) over the sum. |