1 November 2004 Temporal wavelet analysis for deformation and velocity measurement in speckle interferometry
Author Affiliations +
Optical Engineering, 43(11), (2004). doi:10.1117/1.1801472
Abstract
When a continuously deforming object is measured by electronic speckle pattern interferometry (ESPI), the speckle pattern recorded on a camera sensor changes constantly. These time-dependent speckle patterns would provide the deformation history of the object. Various objects are applied with both linearly and nonlinearly varying loads and speckle patterns are captured using a high-speed CCD camera. The temporal intensity variation of each pixel on the recorded images is analyzed by a robust mathematical tool—Morlet wavelet transform instead of conventional Fourier transform. The transient velocity and displacement of each point can be retrieved without the necessity of the temporal or spatial phase unwrapping process. The displacements obtained are compared with those from a temporal Fourier transform, and the results show that the wavelet transform minimizes the influence of noise and provides better results for a linearly varying load. System error in the wavelet analysis for nonlinear load is also discussed.
Yu Fu, Cho Jui Tay, Chenggen Quan, L. J. Chen, "Temporal wavelet analysis for deformation and velocity measurement in speckle interferometry," Optical Engineering 43(11), (1 November 2004). http://dx.doi.org/10.1117/1.1801472
JOURNAL ARTICLE
8 PAGES


SHARE
KEYWORDS
Wavelets

Speckle pattern

Wavelet transforms

Fourier transforms

Continuous wavelet transforms

Error analysis

CCD cameras

RELATED CONTENT

Active thermal testing of moisture in bricks
Proceedings of SPIE (April 06 1993)
Constructing Steane code fault-tolerant gates
Proceedings of SPIE (February 23 2005)
Wavelet-based line simplification
Proceedings of SPIE (October 28 2006)
Time-delay estimation in time-warping environments
Proceedings of SPIE (May 05 2009)

Back to Top