Patent ID: 7353709

Claim:
A method for using a measurement of ultrasonic attenuation to determine a material property of an object, the method comprising: (a) receiving an interaction signal from an ultrasound detector, at a detection location on the object in response to a broadband ultrasonic pulse impinging on the detection location, the ultrasonic pulse having been attenuated in travel through the object; (b) transforming a portion of the interaction signal corresponding to the attenuated pulse from the time domain to the frequency domain, to obtain an amplitude spectrum; (c) comparing the amplitude spectrum with a reference amplitude spectrum to obtain an attenuation spectrum, the reference amplitude spectrum produced using a reference piece having equivalent diffraction properties as the object with respect to the propagating broadband ultrasonic pulse, the reference amplitude spectrum being substantially free of attenuation; (d) determining a best fit of the attenuation spectrum to a model of frequency dependent attenuation that accounts for frequency independent variations of signal strength between the object and the reference piece, to obtain an attenuation parameter; and (e) using the attenuation parameter to compute a material property of the object that depends on the attenuation.