An ultrasonic method for determination of acoustic impedance, time of flight, and attenuation of a thin linear-viscoelastic layer.

A method for the determination of acoustic impedance, time of flight, and attenuation of an immersed thin linear-viscoelastic layer on a substrate of infinite extent is proposed as the transfer functions of the normally incident ultrasonic reflected signals are given. Utilizing the derived analytical expressions related to the measured data, three parameters can be determined without considering the acoustic impedance of the substrate and giving the initial guesses and the corresponding convergence zones. The measurement relations between the layer properties and the three parameters are theoretically derived. The method stability against the experimental noises is numerically investigated. [ABSTRACT FROM AUTHOR]