Reconstruction of the images of reflectors from ultrasonic echo signals using the maximum-entropy method

It is proposed to use the maximum-entropy method (MEM) for processing ultrasonic echo signals for reconstructing images of reflectors with a high signal-to-noise ratio and a low level of “side lobes” of the point-scattering function. When processing echo signals, the pulse-propagation paths can be considered taking reflections from irregular boundaries of a tested object with the wave-type transformation into account. In model experiments, images of reflectors were obtained taking the refractions of rays at the rough surface into account, when echo signals were recorded both using an ordinary single-element transducer in the transceiver mode and an antenna array that recorded echo signals in the double- and triple-scanning modes. The reconstructed images have a resolution that exceeds the resolution according to the Rayleigh criterion. The MEM makes it possible to obtain images of flaws with low-level side lobes, when less than 10% of the complete set of echo signals are used.

[1]  René Marklein,et al.  Three-dimensional imaging system based on Fourier transform synthetic aperture focusing technique , 1990 .

[2]  P. Wilcox,et al.  Post-processing of the full matrix of ultrasonic transmit-receive array data for non-destructive evaluation , 2005 .

[3]  MAXIMUM ENTROPY TOMOGRAPHY , 1996 .

[4]  A. Papoulis,et al.  Detection of hidden periodicities by adaptive extrapolation , 1979 .

[5]  Stephen J. Wernecke,et al.  Maximum Entropy Image Reconstruction , 1977, IEEE Transactions on Computers.

[6]  Peter Hore,et al.  Nuclear Magnetic Resonance , 1995 .

[7]  J. Goodman.  Introduction to Fourier optics , 1969 .

[8]  B. Frieden.  Restoring with maximum likelihood and maximum entropy. , 1972, Journal of the Optical Society of America.

[9]  Solomon Kullback,et al.  Information Theory and Statistics , 1970, The Mathematical Gazette.

[10]  Steven R. Doctor,et al.  Implementation of a Real-Time Ultrasonic Saft System for Inspection of Nuclear Reactor Components , 1987 .

[11]  E. Bazulin,et al.  Application of the maximum entropy method in ultrasound nondestructive testing for scatterer imaging with allowance for multiple scattering , 2010 .

[12]  E. G. Bazulin.  Utilization of double scanning in ultrasonic testing to improve the quality of the scatterer images , 2001 .

[13]  J. Devaney,et al.  1 Super-resolution Processing of Multi-static Data Using Time Reversal and MUSIC A , 2000 .

[14]  A. Shmelev,et al.  Numerical and physical modeling of the tomography process based on third-order nonlinear acoustic effects , 2009 .

[15]  E. Bazulin,et al.  Image quality improvement in ultrasonic nondestructive testing by the maximum entropy method , 2005 .

[16]  P. Young,et al.  Time series analysis, forecasting and control , 1972, IEEE Transactions on Automatic Control.

[17]  S. Kullback,et al.  Information Theory and Statistics , 1959 .

[18]  E. Bazulin.  Two-dimensional adaptive extrapolation of the spectrum of multifrequency acoustic holograms , 1991 .

[19]  E. Iakovleva,et al.  TIME OF FLIGHT INVERSE MATCHING RECONSTRUCTION OF ULTRASONIC ARRAY DATA EXPLOITING FORWARDS MODELS , 2009 .

[20]  W. T. Grandy.  Maximum entropy in action: Buck, Brian and Macaulay, Vincent A., 1991, 220 pp., Clarendon Press, Oxford, £30 pb, ISBN 0-19-8539630 , 1995 .

[21]  R. Gerchberg.  Super-resolution through Error Energy Reduction , 1974 .

[22]  E. G. Bazulin,et al.  Application of an ultrasonic antenna array for registering echo signals by the double-scanning method for obtaining flaw images , 2009 .

[23]  Gwilym M. Jenkins,et al.  Time series analysis, forecasting and control , 1972 .

[24]  E. G. Bazulin.  Determining the flaw type from images obtained by the C-SAFT method with account for transformations of wave types upon reflections of ultrasonic pulses from the irregular boundaries of a test object , 2011 .

[25]  John Skilling,et al.  Maximum Entropy and Bayesian Methods , 1989 .

[26]  M. Srinivasan,et al.  Robust deconvolution of high-frequency ultrasound images using higher-order spectral analysis and wavelets , 2003, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[27]  M. P. Hobson,et al.  Maximum-entropy image reconstruction using wavelets , 2003, astro-ph/0303246.

[28]  Valentin A. Burov,et al.  Modeling of the exact solution of the inverse scattering problem by functional methods , 2010 .