Testing pseudo-linear Zoeppritz approximations: Analytical error expressions

Charles P. Ursenbach

Analytical expressions are derived for the error of contrasts estimated by AVO inversion. This is carried out for three approximations to the Zoeppritz equations, and for both conventional and converted-wave data. The expressions are tested against errors obtained by explicit numerical inversion. The formulae obtained show that errors in P-wave impedance contrasts are an order of magnitude smaller than those of other contrasts. The formulae for errors in shear-wave impedance contrast and density contrast are particularly accurate for linear theories and multicomponent data.