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Proceedings Paper

An improved centroid detection method based on higher moment for Shack-Hartmann wavefront sensor
Author(s): Ai-li Xia; Cai-wen Ma
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Paper Abstract

The accuracy of the Shack-Hartmann wavefront sensor (SHWS) for measuring the distortion wavefront is mainly dependent upon the measurement accuracy of the centroid of the focal spot. Many methods have been presented to improve the accuracy of the wavefront centroid measurement by weakening the influence of various noises, such as the photo noise, the read-out noise, the background noise, unevenness and instability of the light source, etc. In general, these methods mainly use the first moment centroid algorithm to calculate the centroid in the whole sub-aperture. In this paper, we present an improved centroid measurement approach that calculate the centroid of the focal spot more precisely using the higher moment centroid method in an optimized detection window. Based on the improved method, the effects of various noises out of the optimized detection window are almost eliminated; furthermore, the noise influences in the optimized detection window are also weakened due to the more contributions of the focal spot intensity. The experimental results demonstrate that the precision and repeatability of focal spot centroid are more prominent than the results obtained via other commonly centroid methods.

Paper Details

Date Published: 9 November 2010
PDF: 6 pages
Proc. SPIE 7850, Optoelectronic Imaging and Multimedia Technology, 78501Q (9 November 2010); doi: 10.1117/12.870136
Show Author Affiliations
Ai-li Xia, Xi'an Institute of Optics and Precision Mechanics (China)
Graduate Univ. of the Chinese Academy of Sciences (China)
Cai-wen Ma, Xi'an Institute of Optics and Precision Mechanics (China)

Published in SPIE Proceedings Vol. 7850:
Optoelectronic Imaging and Multimedia Technology
Toru Yoshizawa; Ping Wei; Jesse Zheng; Tsutomu Shimura, Editor(s)

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