Temporal wavelet analysis for deformation and velocity measurement in speckle interferometry
When a continuously deforming object is measured by electronic...
Saved in:
| Main Authors: | , , , |
|---|---|
| Other Authors: | |
| Format: | Article |
| Language: | English |
| Published: |
2010
|
| Subjects: | |
| Online Access: | https://hdl.handle.net/10356/91918 http://hdl.handle.net/10220/6474 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Institution: | Nanyang Technological University |
| Language: | English |
| Summary: | 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. |
|---|