Title :
Model-based estimation of ultrasonic echoes. Part II: Nondestructive evaluation applications
Author :
Demirli, Ramazan ; Saniie, Jafar
Author_Institution :
Dept. of Electr. & Comput. Eng., Illinois Inst. of Technol., Chicago, IL, USA
fDate :
5/1/2001 12:00:00 AM
Abstract :
For Part I see ibid., vol.48, no.3, pp.787-802 (2001). Accurate estimation of the ultrasonic echo pattern leading to the physical property of the object is desirable for ultrasonic NDE (nondestructive evaluation) applications. In Part I of this study, we have presented a generalized parametric ultrasonic echo model, composed of a number of Gaussian echoes corrupted by noise, and algorithms for accurately estimating the parameters. In Part II of this study, we explore the merits of this model-based estimation method in ultrasonic applications. This method produces high resolution and accurate estimates for ultrasonic echo parameters, i.e., time of flight (TOF) amplitude, center frequency, bandwidth, and phase. Furthermore, it offers a solution to the deconvolution problem for restoration of the target response, i.e., ultrasonic reflection and transmission properties of materials, from the backscattered echoes. The model-based estimation method makes deconvolution possible in the presence of significant noise. It can also restore closely spaced overlapping echoes beyond the resolution of the measuring system. These properties of the estimation method are investigated in various ultrasonic applications such as transducer pulse-echo wavelet estimation, subsample time delay estimation, and thickness sizing of thin layers.
Keywords :
Gaussian noise; deconvolution; echo; parameter estimation; ultrasonic materials testing; ultrasonic scattering; Gaussian noise; deconvolution; nondestructive evaluation; parameter estimation algorithm; subsample time delay; thin layer thickness measurement; transducer pulse-echo wavelet; ultrasonic backscattering; ultrasonic echo; ultrasonic reflection; ultrasonic transmission; Acoustic applications; Acoustic reflection; Amplitude estimation; Bandwidth; Deconvolution; Delay estimation; Frequency estimation; Gaussian noise; Parameter estimation; Phase estimation;
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on