USE OF HOLOGRAPHIC INTERFEROMETRY AND ELECTRONIC SPECKLE PATTERN INTERFEROMETRY FOR MEASUREMENTS OF DYNAMIC DISPLACEMENTS

The paper presents the use of Holographic Interferometry and Electronic Speckle Pattern Interferometry for the measurement of dynamic surface displacements. A concise theoretical background of the optical phenomena on which the two techniques are based is given. Analysis of holographic and speckle fringe patterns due to dynamic displacements is introduced as a generalisation of the case of fringe patterns due to static displacements. Experimental results obtained on a turbine blade, an aluminium panel and a microsatellite sandwich structure are reported.