Maximum likelihood estimation of A-scan amplitudes for coherent targets in media of unresolvable scatterers

The author derives a maximum-likelihood estimator (MLE) for A-scan amplitudes corresponding to coherent reflectors embedded in media of unresolvable scatterers. The MLE processes sampled RF A-scans from broadband ultrasonic pulse-echo systems. A major source of interference for these signals is the...

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Bibliographische Detailangaben
Veröffentlicht in:IEEE transactions on ultrasonics, ferroelectrics, and frequency control. - 1986. - 39(1992), 3 vom: 28., Seite 422-31
1. Verfasser: Donohue, K D (VerfasserIn)
Format: Aufsatz
Sprache:English
Veröffentlicht: 1992
Zugriff auf das übergeordnete Werk:IEEE transactions on ultrasonics, ferroelectrics, and frequency control
Schlagworte:Journal Article
Beschreibung
Zusammenfassung:The author derives a maximum-likelihood estimator (MLE) for A-scan amplitudes corresponding to coherent reflectors embedded in media of unresolvable scatterers. The MLE processes sampled RF A-scans from broadband ultrasonic pulse-echo systems. A major source of interference for these signals is the backscattered energy from the unresolvable scatterers that exist throughout the beam field. A statistical model is formulated that characterizes the backscattered energy from a resolution cell when a coherent target scatterer is present. It is shown that the MLE is equivalent to a matched filter when the distribution of the interfering back-scatter energy is stationary over the resolution cell. In addition, the form of the MLE is described when the interfering echoes are not stationary within the resolution cell. Experimental results are presented for an adaptive implementation of the MLE applied to flaw detection in stainless steel. The results demonstrate the ability of the MLE to reveal targets masked by grain echoes, without prior knowledge of the gain-echo spectral characteristics
Beschreibung:Date Completed 02.10.2012
Date Revised 12.02.2008
published: Print
Citation Status PubMed-not-MEDLINE
ISSN:1525-8955