6 August 1993 PIV: comparison of three autocorrelation techniques
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Proceedings Volume 2052, Fifth International Conference on Laser Anemometry: Advances and Applications; (1993) https://doi.org/10.1117/12.150548
Event: Laser Anemometry: Advances and Applications: Fifth International Conference, 1993, Koningshof, Veldhoven, Netherlands
Three ways of implementing the 2-dimensional autocorrelation function (ACF) used for the extraction of displacement information in particle image velocimetry (PIV) records have been compared. The three methods are: (1) Numerical computation by means of two consecutive FFT algorithms directly from the digitized image, (2) a hybrid method by which an optical Fourier transform first forms the spatial power spectrum of the image, after which the ACF is computed by a numerical FFT (this method is usually known as the Young's fringe method) and (2) an all-optical correlator. These three methods are compared in terms of resolution and 'quality of data', a term covering signal-to-noise and detectability considerations. In spite of the fact that three methods in principle carry out the same underlying mathematical operation the resulting ACFs may look very different. However, as it turns out, the differences may be explained by artifacts characteristic of the practical implementations, and when these differences are taken into account, the three methods are seen to perform quite similarly.
© (1993) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
C. H. Westergaard, C. H. Westergaard, Preben Buchhave, Preben Buchhave, } "PIV: comparison of three autocorrelation techniques", Proc. SPIE 2052, Fifth International Conference on Laser Anemometry: Advances and Applications, (6 August 1993); doi: 10.1117/12.150548; https://doi.org/10.1117/12.150548

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