Title :
A linear model approach for ultrasonic inverse problems with attenuation and dispersion
Author :
Carcreff, Ewen ; Bourguignon, Sebastien ; Idier, Jerome ; Simon, Laurent
Author_Institution :
Inst. de Rech. en Commun. et Cybernetique de Nantes (IRCCyN), Nantes, France
Abstract :
Ultrasonic inverse problems such as spike train deconvolution, synthetic aperture focusing, or tomography attempt to reconstruct spatial properties of an object (discontinuities, delaminations, flaws, etc.) from noisy and incomplete measurements. They require an accurate description of the data acquisition process. Dealing with frequency-dependent attenuation and dispersion is therefore crucial because both phenomena modify the wave shape as the travel distance increases. In an inversion context, this paper proposes to exploit a linear model of ultrasonic data taking into account attenuation and dispersion. The propagation distance is discretized to build a finite set of radiation impulse responses. Attenuation is modeled with a frequency power law and then dispersion is computed to yield physically consistent responses. Using experimental data acquired from attenuative materials, this model outperforms the standard attenuation-free model and other models of the literature. Because of model linearity, robust estimation methods can be implemented. When matched filtering is employed for single echo detection, the model that we propose yields precise estimation of the attenuation coefficient and of the sound velocity. A thickness estimation problem is also addressed through spike deconvolution, for which the proposed model also achieves accurate results.
Keywords :
acoustic signal processing; inverse problems; matched filters; ultrasonic absorption; ultrasonic measurement; ultrasonic scattering; attenuative materials; data acquisition process; frequency dependent attenuation; frequency dependent dispersion; frequency power law; incomplete measurements; inversion context; linear model approach; matched filtering; model linearity; noisy measurements; object spatial properties; physically consistent responses; single echo detection; spike train deconvolution; synthetic aperture focusing; thickness estimation problem; travel distance; ultrasonic attenuation; ultrasonic data taking linear model; ultrasonic dispersion; ultrasonic inverse problems; ultrasonic tomography; ultrasonic wave shape; Acoustics; Attenuation; Computational modeling; Data models; Dispersion; Transducers; Transfer functions;
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
DOI :
10.1109/TUFFC.2014.3018