Signal processing in optical coherence tomography for aerospace material characterization

Journal article (2013)
Department
Aerspace Structures and Materials (Aerospace Engineering) (TU Delft)
Copyright: ©2013 The Authors and SPIE
DOI: https://doi.org/doi:10.1117/1.OE.52.3.033201
Signal processing Microstructure Optical coherence tomography Demodulation Median filter Aerospace materials
More Info
expand_more

Published Date

04-03-2013

Reuse Rights

Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.

Source:

Optical Engineering, 52(3)2013

ISSN:

0091-3286

Source:

http://opticalengineering.spiedigitallibrary.org/article.aspx?articleid=1660103

Faculty

Aerospace Engineering

Department

Aerspace Structures and Materials

Abstract

Based on a customized time-domain optical coherence tomography (OCT) system, a series of signal processing approaches have been designed and reviewed. To improve demodulation accuracy and image quality, demodulation approaches such as median filter, Hilbert transform, and envelope detector were investigated with simulated as well as experimental data. Without noise, the Hilbert transform has the best performance, but after considering the narrow-band noise in the modulated signal, the envelope detector was selected as the ideal demodulation technique. To reduce noise and enhance image contrast, digital signal processing techniques such as a bandpass filtering and two-dimensional median filtering were applied before and after the demodulation, respectively. Finally with integration of the customized OCT setup and designed signal processing algorithms, aerospace materials, such as polymer coatings and glass-fiber composites, were successfully characterized. The cross-sectional images obtained clearly show the microstructures of the materials.

Files

Liu.pdf
(pdf | 1.45 Mb)