A new speckle photographic technique is proposed to measure the 3-D displacement of a curved surface. The movement of the image speckle is recorded on a cylindrical surface, whereby the defocussing is dismissed. The principle of the method is described. The relations between the displacement of the model and the speckle movement on the cylindrical image surface are derived. Experimental results are given and compared with those calculated by the finite-element method.
"Three Dimensional Displacement Measurement With A Novel Speckle Method", Proc. SPIE 1121, Interferometry '89, (3 April 1989); doi: 10.1117/12.961308; https://doi.org/10.1117/12.961308