In seismology, impedance of a rock layer is defined as the product of bulk density ρB and P-wave velocity VP:
The normal incidence (vertical) reflection coefficient between an upper layer i and a lower layer i + 1 is given by
S-wave impedance is the product of bulk density and S-wave velocity
Elastic impedance (EI) is an offset (or angle) dependent property for non-normal angles of incidence. It was first described by Connolly, 1999.
P to S converted wave elastic impedance (PSEI)
Also called Shear wave impedance.