Analogue and digital developments for project DISCO at Budapest University of Technology and Economics

The paper summarizes main researches done at the Department of Physics for DISCO project - Distant Shape Control. The main contribution to the project is the comparative technique - difference holographic interferometry (DHI) - elaborated earlier and developed continuously at the Department. Applications of digital holography are presented which include direct and comparative displacement measurement with both digital and analogue reconstructions. A special attention is taken to the increasing practical upper measuring limit of both analogue and digital holographic interferometry that is well below its theoretical value and is determined by evaluation system used and by peculiarities of the actual interference pattern. Because of the space and time limitations the main ranges of the work are presented here; for further details the reader is kindly referred to papers of F. Gyimesi at al., ("Two wavelength contouring in difference holographic interferometry and DISCO") and J . Kornis at al. ("Comparative displacement measurement by digital holographic interferometry") in this volume.