2014
Ellipse fitting by nonlinear constraints to demodulate quadrature homodyne interferometer signals and to determine the statistical uncertainty of the interferometric phase
KONING, Rainer; Gejza WIMMER a Viktor WITKOVSKÝZákladní údaje
Originální název
Ellipse fitting by nonlinear constraints to demodulate quadrature homodyne interferometer signals and to determine the statistical uncertainty of the interferometric phase
Autoři
KONING, Rainer; Gejza WIMMER a Viktor WITKOVSKÝ
Vydání
MEASUREMENT SCIENCE & TECHNOLOGY, BRISTOL, IOP PUBLISHING LTD, 2014, 0957-0233
Další údaje
Jazyk
angličtina
Typ výsledku
Článek v odborném periodiku
Obor
20102 Construction engineering, Municipal and structural engineering
Stát vydavatele
Velká Británie a Severní Irsko
Utajení
není předmětem státního či obchodního tajemství
Odkazy
Impakt faktor
Impact factor: 1.433
Označené pro přenos do RIV
Ano
Kód RIV
RIV/00216224:14310/14:00080210
Organizační jednotka
Přírodovědecká fakulta
UT WoS
EID Scopus
Klíčová slova anglicky
Heydemann correction; homodyne interferometry; demodulation of quadrature homodyne interferometer signals; measurement uncertainty
Příznaky
Mezinárodní význam, Recenzováno
Změněno: 19. 12. 2019 11:15, Mgr. Marie Novosadová Šípková, DiS.
Anotace
V originále
Optical interferometers are widely used in dimensional metrology applications. Among them are many quadrature homodyne interferometers. These exhibit two sinusoidal interference signals shifted, in the ideal case, by 90 degrees to allow a direction sensitive detection of the motion responsible for the actual phase change. But practically encountered signals exhibit additional offsets, unequal amplitudes and a phase shift that differs from 90 degrees. In order to demodulate the interference signals the so called Heydemann correction is used in almost all cases, i.e. an ellipse is fitted to both signals simultaneously to obtain the offsets, amplitude and the phase lag. Such methods are typically based on a simplified least squares fit that leads to a system of linear equations, which can be solved directly in one step. Although many papers related to this subject have been published already only a few of them consider the uncertainties related to this demodulation scheme. In this paper we propose a new method for fitting the ellipse, based on minimization of the geometric distance between the measured and fitted signal values, which provides locally best linear unbiased estimators (BLUEs) of the unknown model parameters, and simultaneously also estimates of the related statistical uncertainties, including the uncertainties of estimated phases and/or displacements.