Ultrasonic Flaw Detection and Imaging through Reverberant Layers via Subspace Analysis and Projection
Joint Authors
Amin, Moeness G.
Demirli, Ramazan
Shen, Xizhong
Zhang, Yimin D.
Source
Advances in Acoustics and Vibration
Issue
Vol. 2012, Issue 2012 (31 Dec. 2012), pp.1-10, 10 p.
Publisher
Hindawi Publishing Corporation
Publication Date
2012-07-18
Country of Publication
Egypt
No. of Pages
10
Main Subjects
Abstract EN
Ultrasonic flaw detection and imaging through reverberant layers are challenging problems owing to the layer-induced reverberations and front surface reflections.
These undesired signals present a strong clutter and mask the flaw echoes.
In this paper, a subspace-based approach is developed for removing, or significantly reducing, the unwanted reverberations, enabling proper flaw detection and imaging.
The technique utilizes a set of independent clutter-only reference measurements of the material through the layer.
If these measurements are not available, array measurements of the material with flaws are used instead.
The clutter, due to its high strength relative to the flaw reflections, forms a subspace spanned by the eigenvectors corresponding to the dominant eigenvalues of the data covariance matrix.
The clutter subspace is estimated and removed using orthogonal subspace projection.
The clutter usually occupies multidimension subspace that is dependent on the level of coupling, material inhomogeneity, surface roughness, and the sampling rate of the measurements.
When the clutter-only reference is not available, information theoretic techniques are used to estimate the dimension of the clutter subspace so that clutter signals are sufficiently suppressed without distorting the flaw signals.
The effectiveness of the proposed approach is demonstrated using simulations and real measurement results.
American Psychological Association (APA)
Demirli, Ramazan& Amin, Moeness G.& Shen, Xizhong& Zhang, Yimin D.. 2012. Ultrasonic Flaw Detection and Imaging through Reverberant Layers via Subspace Analysis and Projection. Advances in Acoustics and Vibration،Vol. 2012, no. 2012, pp.1-10.
https://search.emarefa.net/detail/BIM-511338
Modern Language Association (MLA)
Demirli, Ramazan…[et al.]. Ultrasonic Flaw Detection and Imaging through Reverberant Layers via Subspace Analysis and Projection. Advances in Acoustics and Vibration No. 2012 (2012), pp.1-10.
https://search.emarefa.net/detail/BIM-511338
American Medical Association (AMA)
Demirli, Ramazan& Amin, Moeness G.& Shen, Xizhong& Zhang, Yimin D.. Ultrasonic Flaw Detection and Imaging through Reverberant Layers via Subspace Analysis and Projection. Advances in Acoustics and Vibration. 2012. Vol. 2012, no. 2012, pp.1-10.
https://search.emarefa.net/detail/BIM-511338
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references
Record ID
BIM-511338