Palmer, Stuart B., Dixon, S. and Petcher, P. A. (2012) Obtaining more information from time-of-flight-diffraction measurements. In: Nondestructive Characterization for Composite Materials, Aerospace Engineering, Civil Infrastructure, and Homeland Security 2012, San Diego, CA, 12-15 Mar 2012. Published in: Proceedings of SPIE - The International Society for Optical Engineering, Vol.8347 83470Z-83470Z. doi:10.1117/12.913605 ISSN 0277-786X.

Research output not available from this repository.

Request-a-Copy directly from author or use local Library Get it For Me service.

Request Changes to record.

Abstract

Time of flight diffraction and imaging (TOFDI) is based on time of flight diffraction (TOFD); it adds cross-sectional imaging to examine the bulk of a sample. Multiple wave modes are generated by a pulsed laser beam, ablative source and are received by a sparse array of non-contact electromagnetic acoustic transducers (EMATs). A B-scan is formed from multiple data captures (A-scans), with time and scan axes, and colour representing amplitude. B-scans may contain horizontal lines from surface waves propagating directly from emitter to receiver, or via a back-wall reflection, and angled lines after reflection off a surface edge. A Hough transform (HT), modified to deal with the constraints of a B-scan, can remove such lines. A parabola matched filter has been developed to identify features in the B-scan caused by scattering from point-like features, reducing them to peaks. The processed B-scan is processed further to form a cross-sectional image, enabling detection and positioning of multiple defects. Phase correlation of camera images is used to track the relative position between transducer and sample to sub-pixel precision. © 2012 SPIE.

Item Type:	Conference Item (Paper)
Divisions:	Faculty of Science, Engineering and Medicine > Science > Physics
Journal or Publication Title:	Proceedings of SPIE - The International Society for Optical Engineering
Publisher:	S P I E - International Society for Optical Engineering
ISSN:	0277-786X
Official Date:	2012
Dates:	Date Event 2012 Published
Volume:	Vol.8347
Page Range:	83470Z-83470Z
DOI:	10.1117/12.913605
Status:	Peer Reviewed
Publication Status:	Published
Access rights to Published version:	Restricted or Subscription Access
Conference Paper Type:	Paper
Title of Event:	Nondestructive Characterization for Composite Materials, Aerospace Engineering, Civil Infrastructure, and Homeland Security 2012
Type of Event:	Conference
Location of Event:	San Diego, CA
Date(s) of Event:	12-15 Mar 2012

Request changes or add full text files to a record

Repository staff actions (login required)

View Item