Sensors 2008, 8(12), 7609-7635; doi:10.3390/s8127609

High Precision Signal Processing Algorithm for White Light Interferometry

Received: 22 April 2008; in revised form: 7 November 2008 / Accepted: 7 November 2008 / Published: 1 December 2008
(This article belongs to the Special Issue Sensor Algorithms)
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract: A new signal processing algorithm for absolute temperature measurement using white light interferometry has been proposed and investigated theoretically. The proposed algorithm determines the phase delay of an interferometer with very high precision (<< one fringe) by identifying the zero order fringe peak of cross-correlation of two fringe scans of white light interferometer. The algorithm features cross-correlation of interferometer fringe scans, hypothesis testing and fine tuning. The hypothesis test looks for a zero order fringe peak candidate about which the cross-correlation is symmetric minimizing the uncertainty of mis-identification. Fine tuning provides the proposed algorithm with high precision subsample resolution phase delay estimation capability. The shot noise limited performance of the proposed algorithm has been analyzed using computer simulations. Root-mean-square (RMS) phase error of the estimated zero order fringe peak has been calculated for the changes of three different parameters (SNR, fringe scan sample rate, coherence length of light source). Computer simulations showed that the proposed signal processing algorithm identified the zero order fringe peak with a miss rate of 3 x 10-4 at 31 dB SNR and the extrapolated miss rate at 35 dB was 3 x 10-8. Also, at 35 dB SNR, RMS phase error less than 10-3 fringe was obtained. The proposed signal processing algorithm uses a software approach that is potentially inexpensive, simple and fast.
Keywords: Phase delay estimation; white light interferometry; signal processing algorithm; fine tuning
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MDPI and ACS Style

Kim, J.H. High Precision Signal Processing Algorithm for White Light Interferometry. Sensors 2008, 8, 7609-7635.

AMA Style

Kim JH. High Precision Signal Processing Algorithm for White Light Interferometry. Sensors. 2008; 8(12):7609-7635.

Chicago/Turabian Style

Kim, Jeonggon H. 2008. "High Precision Signal Processing Algorithm for White Light Interferometry." Sensors 8, no. 12: 7609-7635.

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