Finding small displacements of recorded speckle patterns: revisited

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Abstract

An analytical expression for the bias effect in digital speckle correlation is derived based on a Gaussian approximation of the spatial pixel size and array extent. The evaluation is carried out having assumed an incident speckle field. The analysis is focused on speckle displacements in the order of one pixel, thus having no speckle decorrelation. Furthermore, sensitivity is a main issue wherefore we need speckles close to the pixel size, which means that speckle averaging becomes important, and that Nyquist’s criteria may not be fulfilled. Based on these observations, a new correlation method is introduced, which alleviates the need to know the expected shape of the crosscovariance between the original and the off-set recorded speckle pattern. This concept calls for correlating the crosscovariance with the auto covariance, which essentially carries information on the expected shape of the crosscovariance.
Original languageEnglish
Title of host publicationProceedings of SPIE
EditorsFernando Mendoza Santoyo
Number of pages8
Volume9660
PublisherSPIE - International Society for Optical Engineering
Publication date2015
Article number96601J
DOIs
Publication statusPublished - 2015
EventSPECKLE 2015: VI International Conference on Speckle Metrology - Guanajuato, Mexico
Duration: 24 Aug 201526 Aug 2015

Conference

ConferenceSPECKLE 2015
CountryMexico
CityGuanajuato
Period24/08/201526/08/2015
SeriesProceedings of SPIE, the International Society for Optical Engineering
Volume9660
ISSN0277-786X

Bibliographical note

Copyright 2015 Society of Photo Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic electronic or print reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.

Cite this

Hanson, S. G., Jakobsen, M. L., Chakrabarti, M., & Yura, H. (2015). Finding small displacements of recorded speckle patterns: revisited. In F. M. Santoyo (Ed.), Proceedings of SPIE (Vol. 9660). [96601J] SPIE - International Society for Optical Engineering. Proceedings of SPIE, the International Society for Optical Engineering, Vol.. 9660 https://doi.org/10.1117/12.2195631