Moiré pattern

About: Moiré pattern is a research topic. Over the lifetime, 1917 publications have been published within this topic receiving 27176 citations. The topic is also known as: moiré fringes & moire pattern.

Moiré Fringe Phase Difference Measurement Based on Spectrum Zoom Technology

Abstract: Grating displacement measurement technique is an important means to achieve precise displacement measurement of nanometer scale. Moire fringe phase difference measurement is the basis of grating displacement measurement technique. Traditional Moire fringe subdivision method based on DFT algorithm has low frequency resolution relatively when extracting Moire fringe fundamental frequency spectral line, which causes frequency and phase measurement errors of Moire fringe fundamental frequency. CZT spectrum zoom technique can improve the frequency resolution of frequency band near Moire fringe fundamental frequency and get fundamental frequency spectrum lines more exactly, which can solve the problem of low frequency resolution of DFT. The paper studies the relation of Moire fringe phase difference and grating displacement, and analyzes the working principles of DFT and CZT spectrum zoom method. DFT and CZT spectrum zoom are used for Moire fringe spectrum analysis and phase difference calculation respectively. Simulation results show measurement error of Moire fringe phase difference with DFT algorithm is in 10 -3 degree scale, while measurement error with CZT spectrum zoom algorithm is approximate 0 degree. The comparison results show CZT spectrum zoom method has better performance and applicability, which improves the phase difference measurement accuracy of Moire fringe effectively. DOI: http://dx.doi.org/10.11591/telkomnika.v11i10.3461

Demodulation of moire fringes in digital holographic interferometry using an extended Kalman filter.

Abstract: This paper presents a method for extracting multiple phases from a single moire fringe pattern in digital holographic interferometry. The method relies on component separation using singular value decomposition and an extended Kalman filter for demodulating the moire fringes. The Kalman filter is applied by modeling the interference field locally as a multi-component polynomial phase signal and extracting the associated multiple polynomial coefficients using the state space approach. In addition to phase, the corresponding multiple phase derivatives can be simultaneously extracted using the proposed method. The applicability of the proposed method is demonstrated using simulation and experimental results.

Line Thinning Algorithm For Nearly Straight Moire Fringes

Abstract: A simple noniterative line-thinning algorithm, which is suitable for nearly straight interferometric and moire fringes, is proposed. The algorithm was found to be fast and accurate. An error analysis is presented.