Two-dimensional deconvolution applied to phase-stepped shearography

Abstract Shearography can be applied as a non-contact inspection technique with which small local deformations of an object surface can be visualised. When using phase-stepped Shearography, the measurement results are quantitative data. But as they depict the displacement difference over the shear vector, the data do not directly give information on the actual deformation. Using digital image processing, images generated by a phase-stepped Shearography are processed by a deconvolution technique, resulting in quantitative displacement data. The deconvolution technique developed at Fokker Aircraft is described and deconvolution measurement results are shown.