DocumentCode :
3597489
Title :
Model based time-frequency estimation of ultrasonic echoes for NDE applications
Author :
Demirli, Ramazan ; Saniie, Jafar
Author_Institution :
Dept. of Electr. & Comput. Eng., Illinois Inst. of Technol., Chicago, IL, USA
Volume :
1
fYear :
2000
fDate :
10/1/2000 12:00:00 AM
Firstpage :
785
Abstract :
Modeling the ultrasonic signals in terms of the Gaussian echoes assures a solution for signal parameters and a technique for time-frequency representation. In this study, the parameter estimation is addressed using iterative Maximum A Posteriori (MAP) estimation algorithms. To reduce the computational complexity, we have developed a divide-and-conquer estimation procedure. Upon estimation, we have explored the merits of this model-based technique for time-frequency analysis of ultrasonic echoes. In particular, we are presenting ultrasonic experimental data where the microstructure scattering echoes dominate the flaw echoes (SNR is about 0 dB). This type of data is used to demonstrate the effectiveness of model based time-frequency representation over conventional techniques such as Wigner-Ville distribution and short-time Fourier transform
Keywords :
divide and conquer methods; echo; flaw detection; iterative methods; maximum likelihood estimation; time-frequency analysis; ultrasonic materials testing; Gaussian echo; computational complexity; divide-and-conquer method; flaw detection; iterative MAP algorithm; microstructure scattering; parameter estimation; time-frequency analysis; ultrasonic NDE; Amplitude estimation; Application software; Computational complexity; Fourier transforms; Frequency estimation; Gaussian noise; Parameter estimation; Phase estimation; Statistics; Time frequency analysis;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Ultrasonics Symposium, 2000 IEEE
ISSN :
1051-0117
Print_ISBN :
0-7803-6365-5
Type :
conf
DOI :
10.1109/ULTSYM.2000.922660
Filename :
922660
Link To Document :
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