Optimal re-referencing rate for in-plane dynamic speckle interferometry

Abstract

We investigate experimentally the optimal rate at which the reference speckle pattern should be updated when dynamic speckle interferometry is used to measure transient in-plane displacement fields. Images are captured with a high-speed camera and phase shifting and phase unwrapping are done temporally. For a wide range of in-plane velocities, up to a maximum of 40% of the Nyquist limit, the random errors in the calculated displacement field are minimized by updating the reference speckle pattern after a speckle displacement of 1/10 of the pixel spacing. The technique is applied to measurements of microscale deformation fields within an adhesive joint in a carbon-fiber epoxy composite.

Axial loading verification method for small bones using carrier fringes in speckle pattern interferometry

“…However, if we want to know the effect of greater loads, further consecutive deformation stages can be implemented and the final map of bone micro-displacements can be found by the simple expedient of adding the micro-displacement maps that are obtained at each stage of deformation. This technique is known as re-referencing [9].…”