TITLE

Improving the resolution of ultrasonic data through deconvolution

AUTHOR(S)
Gautier, S.; Lavayssie`re, B.; Besnerais, G. Le
PUB. DATE
May 2000
SOURCE
AIP Conference Proceedings;2000, Vol. 509 Issue 1, p699
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Ultrasonic nondestructive testing data contains information about breaks in the inspected medium. Discontinuities due to a defect can be identified through the interpretation of those data. Still, the interesting information about the discontinuities does not always appear directly in the ultrasonic data. Firstly, the presence of each discontinuities is “diluted” in the data; such an effect creates difficulty for the data interpretation, especially when the discontinuities are very close together, several echoes are then mixed in on widely spread echo. Secondly, when the structure of the medium granular, the ultrasonic data can be corrupted by a strong speckle noise. Thus, the proposed signal processing helps for the data interpretation, by improving the resolution and suppressing the noise. The observation model that relates the discontinuities to the data is modeled as a convolution process. The goal of the deconvolution processing is to recover the discontinuities from the data. So as to improve classical deconvolution results, we propose to account both for the data and for the a priori spikiness of the discontinuities. Processing results of real data sets are given for the inspection of austeno-ferritic steel blocks, mixed echoes are separated and the resolution is highly improved. © 2000 American Institute of Physics.
ACCESSION #
6029061

 

Related Articles

  • 1164. Lamb wave signal retrieval by wavelet ridge. Xiao Chen; Yang Gao; Lisuo Bao // Journal of Vibroengineering;Feb2014, Vol. 16 Issue 1, p464 

    Lamb wave testing is one of the important methods in ultrasonic nondestructive testing. One of the key technologies in the Lamb wave testing is to get a clear signal. In this paper, a signal retrieval method for the Lamb wave signal from noisy signals is presented on the basis of its wavelet...

  • Discrete wavelet analysis of two-dimensional signals. Asamoah, F. // International Journal of Electrical Engineering Education;Apr2002, Vol. 39 Issue 2, p162 

    Discrete wavelet transform using Daubechies coefficients is applied to decompose a two-dimensional signal into levels. Examples are given using BMP images of a sheep and a thumbprint. The size of the two- dimensional signal is 2[sup N] by M. It is shown that it is not necessary for M to be a...

  • Wavelet analysis of signals with gaps. Frick, Peter; Grossmann, Alex // Journal of Mathematical Physics;Aug98, Vol. 39 Issue 8, p4091 

    Presents an algorithm of spectral analysis of signals with gaps. Use of a modified continuous wavelet transform in the analysis; Characterization of the wavelet family by an additional parameter; Formulation of three theorems concerning the properties of gapped wavelet transform.

  • Multidimensional signal processing for ultrasonic signal classification. Kim, J.; Ramuhalli, P.; Udpa, L.; Udpa, S. // AIP Conference Proceedings;2001, Vol. 557 Issue 1, p595 

    Neural network based signal classification systems are being used increasingly in the analysis of large volumes of data obtained in NDE applications. One example is in the interpretation on ultrasonic signals obtained from inspection of welds where signals can be due to porosity, slag, lack of...

  • An Approximation to Sparse-Spike Reflectivity Using the Gold Deconvolution Method. Dondurur, Derman // Pure & Applied Geophysics;Oct2010, Vol. 167 Issue 10, p1233 

    Wiener deconvolution is generally used to improve resolution of the seismic sections, although it has several important assumptions. I propose a new method named Gold deconvolution to obtain Earth’s sparse-spike reflectivity series. The method uses a recursive approach and requires the...

  • Passive impacts localization based on dispersion compensation and cross-correlated signals wavelet analysis. Perelli, Alessandro; Marchi, Luca De; Marzani, Alessandro; Speciale, Nicolò // AIP Conference Proceedings;5/24/2012, Vol. 1433 Issue 1, p431 

    A method for impact location in plate-like structures with a passive sensors network is proposed. The approach is based on guided waves dispersion compensation joint with a distance-frequency analysis obtained through a wavelet basis of cross-correlated signals. In passive monitoring techniques...

  • Variable mixing frequency method for accurate and convenient measurement of ultrasonic velocity. Kojima, Akira; Tozaki, Ken-ichi; Akao, Fumio // Review of Scientific Instruments;Jun86, Vol. 57 Issue 6, p1179 

    A simple and convenient method for the accurate measurement of ultrasonic velocity is presented using a commercially available pulsed ultrasonic oscillator and receiver. The principle of operation of the present method belongs to the variable frequency method. The cw signal by the rf signal...

  • Wave Propagation in Multi-Wire Strands by Wavelet-Based Laser Ultrasound. P. Rizzo; F. L. di Scalea // Experimental Mechanics;Aug2004, Vol. 44 Issue 4, p407 

    Methods based on guided ultrasonic waves are gaining increasing attention for the non-destructive inspection and condition monitoring of multi-wire strands used in civil structures such as prestressing tendons and cable stays. In this paper we examine the wave propagation problem in seven-wire...

  • Medical Image Fusion via an Effective Wavelet-Based Approach. Yong Yang; Dong Sun Park; Shuying Huang; Nini Rao // EURASIP Journal on Advances in Signal Processing;2010, Special section p1 

    A novel wavelet-based approach for medical image fusion is presented, which is developed by taking into not only account the characteristics of human visual system (HVS) but also the physical meaning of the wavelet coefficients. After the medical images to be fused are decomposed by the wavelet...

Share

Read the Article

Courtesy of VIRGINIA BEACH PUBLIC LIBRARY AND SYSTEM

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics