Laser ultrasonic signal processing: A model-reference approach

Journal Article · Mon Jul 01 04:00:00 EDT 1996 · Journal of the Acoustical Society of America

DOI:https://doi.org/10.1121/1.415954· OSTI ID:285548

Candy, J V; Thomas, G H; Chinn, D J ^[1]; Spicer, J B ^[2]

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1. Lawrence Livermore National Laboratory, P.O. Box 808, L-437, Livermore, California 94550 (United States)
2. The Johns Hopkins University, Center for Nondestructive Evaluation, Baltimore, Maryland 21218 (United States)

A model-reference approach is developed to solve the signal enhancement problem of a laser ultrasonics application for nondestructive evaluation. In this problem a sophisticated laser thermoelastic propagation model is used to synthesize the surface displacement of the specimen under test. Once synthesized, this model response is used as the reference signal in an optimal (minimum error variance) signal enhancement scheme. Both fixed and adaptive processors are considered in this application where it is shown that a significant improvement in signal levels can be achieved over the usual methods to enhance noisy data acquired from a Michelson interferometric measurement system and increase its overall sensitivity.

• Research Organization: Lawrence Livermore National Laboratory
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 285548
• Journal Information: Journal of the Acoustical Society of America, Journal Name: Journal of the Acoustical Society of America Journal Issue: 1 Vol. 100; ISSN 0001-4966; ISSN JASMAN
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
DISPLACEMENTS
LASER RADIATION
MICHELSON INTERFEROMETER
NOISE
NONDESTRUCTIVE TESTING
SIGNAL CONDITIONING
SURFACES
THERMOELASTICITY
ULTRASONIC TESTING