13th International Conference on Fracture June 16–21, 2013, Beijing, China -2- holographic and speckle interferometry there is a number of restrictions, which connected with existence of own noise (speckles), which lead to reduction of sensitivity and accuracy of measurements. Besides, speckle noise leads to restriction of measurement of displacements with great values of a gradient. Also we will note that existence of own noise (speckles) complicates processing of interferential pictures, both in the holographic, and the speckle interferometry and becomes impossible at research of high-frequency vibrations, because the contrast of interference fringes is falls. A problem of processing of the holographic and speckle interferograms the huge attention is paid [5-7]. Standard methods of the digital holographic and speckle interferometry, as a rule, don't allow to observe dynamic processes of solid mechanics in real time as at researches are generally used: averaging method in time; method of two expositions or pulse method. In this work the new method of registration dynamic displacements of a research surface of object in large range of measured value of displacements and in the large frequency range on the basis of the analysis of distribution of intensity in the single speckle is considered. Such decision allows to overcome restrictions which are connected with existence of own noise (speckles) in the holographic and speckle interferometry and to register dynamic displacements in real time. 2. Speckle and practical application 2.1. Speckle pattern When lighting by coherent radiation a rough surface because of scattering of a coherent radiation in space the complicated interference pattern, which is called speckle pattern, is formed. The characteristic kind of speckle pattern is presented in Fig. 1. Figure 1. Photography of speckle patterns Distinguish two kind of speckle patterns: a) the objective - formed in space at the expense of an interference of a large set of the reflected beams from a rough surface, and which can be registered directly without optical system on a photographic material; b) the subjective - formed and recorded on a photographic material by means of optical system in the plane of the image of a researched rough surface. The sizes, longitudinal — L and transversal – H, of a speckle in objective and subjective speckle patterns are estimated on known formulas [1]: 2 4 L , (1) 1,22 H , (2)
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