Identification of parametric models for ultrasonic wave propagation in the presence of absorption and dispersion

Acoustic wave propagation in an absorptive and dispersive medium is usually described using models derived from a nearly local form of the Kramers-Kronig relationship, e.g., Q- and relaxation models. A modeling approach based on rational transfer function models for the generalized Hooke's law is presented. The assumptions and restrictions of models based on the nearly local absorption-dispersion relations and rational transfer function models are discussed. Using identification techniques, it is experimentally shown that the rational transfer function models explain the ultrasonic wave propagation in an absorptive-dispersive medium much better than the classical Q-models.