Cart (Loading....) | Create Account
Close category search window
 

Reliable estimation of virtual source position for SAFT imaging

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

4 Author(s)
Chih-Hsiung Chang ; Gen. Educ. Center, Nat. Chiayi Univ., Chiayi, Taiwan ; Young-Fo Chang ; Yushieh Ma ; Shung, K.K.

The synthetic aperture focusing technique (SAFT), employing a scanned focused transducer as a virtual source, is commonly used to image flaws in immersion testing. The position of a virtual source is estimated from rays emitted from the rim of a focused transducer. However, it is often found that the virtual source position cannot be uniquely determined because of severe focal spot aberration at the focal zone. Based on an analysis of the energy radiated from the focused transducer and the refracted energy varied with the incident angle of ultrasound, we propose that paraxial rays emitted from the focused transducer are the best for estimating the position of a virtual source for incorporation into SAFT. This study results also shows that by using this simple virtual source position estimation for SAFT, the axial resolution and SNR of the reconstructed image can be greatly improved. This new approach minimizes the effect of such factors as refraction at high-velocity-contrast interfaces, distance of the transducer to the couplant-specimen interface, and the focal length of a focused transducer, which may cause focal spot aberration resulting in decreased sensitivity in SAFT imaging.

Published in:

Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on  (Volume:60 ,  Issue: 2 )

Date of Publication:

February 2013

Need Help?


IEEE Advancing Technology for Humanity About IEEE Xplore | Contact | Help | Terms of Use | Nondiscrimination Policy | Site Map | Privacy & Opting Out of Cookies

A not-for-profit organization, IEEE is the world's largest professional association for the advancement of technology.
© Copyright 2014 IEEE - All rights reserved. Use of this web site signifies your agreement to the terms and conditions.