Displacement Measurement from Double-exposure Laser Photographs
- 1 April 1972
- journal article
- research article
- Published by Taylor & Francis Ltd in Optica Acta: International Journal of Optics
- Vol. 19 (4), 253-271
- https://doi.org/10.1080/713818559
Abstract
Surface displacement can be measured by recording a double-exposure photograph of the laser-illuminated object, followed by optical processing of the recorded speckle-pattern image. The analysis can either be on a point-by-point basis, or by a spatial filtering technique which resolves the motion in any desired direction orthogonal to the line of sight. The limits within which the technique may be used to measure lateral translations and rotations of the surface are examined theoretically and experimentally, and the effect of lens aberrations and surface scattering properties are discussed. Surface tilt may also be measured by recording a defocused double exposure image and analysing its optical transform. The photographic techniques described can be extended to measuring surface vibration, by recording a single ‘time-averaged’ exposure and examining the modified optical transform fringe pattern.Keywords
This publication has 6 references indexed in Scilit:
- Application of Speckling for In-plane Vibration AnalysisOptica Acta: International Journal of Optics, 1971
- Recording of In-plane Surface Displacement by Double-exposure Speckle PhotographyOptica Acta: International Journal of Optics, 1970
- Laser Speckle and Its EliminationIBM Journal of Research and Development, 1970
- Interferometric displacement measurement on scattering surfaces utilizing speckle effectJournal of Physics E: Scientific Instruments, 1970
- Formation and Localization of Holographically Produced Interference FringesOptica Acta: International Journal of Optics, 1969
- Production of Multiple Beam Fringes from Photographic ScatterersOptica Acta: International Journal of Optics, 1968