SHEAR MEASUREMENT IN DIGITAL SPECKLE SHEARING INTERFEROMETRY USING DIGITAL CORRELATION

Accurate computations of surface slope deformation based on digital sp eckle shearing interferometry fringe patterns require a precise measur e of the amount of shear introduced. A previous method of employing im age processing, while providing accurate and fast measurements, is lim ited by the need to place a tape target on the object surface. In this paper, a novel method employing digital correlation is demonstrated t o obviate this requirement while maintaining accurate mensurations of shear. It also allows automated measurement procedures to be readily i ncorporated.