Abstract
Electronic speckle pattern interferometry is based on the use of the coherent speckle pattern effect to acquire surface data combined with the use of closed circuit television, and a special video processing unit, to extract measurement information. Developments at Loughborough have grown directly from the application of holographic interferometry (HI) for engineering measurement purposes and the electronic speckle pattern interferometer (ESPI) carries out a function exactly analogous to both time averaged HI and real time HI.