scholarly journals The theoretical measurement error of a novel static polarization wind imaging interferometer

2010 ◽  
Vol 59 (6) ◽  
pp. 4369
Author(s):  
Liu Ning ◽  
Zhang Chun-Min ◽  
Wang Jin-Chan ◽  
Mu Ting-Kui
Author(s):  
C. Zhang ◽  
T. Yan ◽  
T. Mu ◽  
Y. He

Abstract. Polarization array based polarization Michelson wind field detection interferometer is a new type of interferometer for detecting atmospheric temperature and wind field velocity. We proposed a theoretical model and design of the novel static polarization wind imaging interferometer (NSPWII). It consists of a group of polarizers and waveplates, a polarization beamsplitter, a field widened Michelson interferometer, a pyramid prism, and a polarization array. Based on the principle of polarization interference, a polarization array composed of four polarizers with 45° polarization directions differences is directly in front of the detector, and four modulated light beams from the pyramid prism pass through the four polarizers. Then, interferograms with four different intensity are imaged on the detector simultaneously, which further provides the atmospheric temperature and wind field velocity. The advantages of this instrument are static (no moving parts), achromatic, and temperature compensated. It is capable of measuring the upper atmospheric wind field in real time with a high precision.


Optik ◽  
2013 ◽  
Vol 124 (24) ◽  
pp. 6932-6935
Author(s):  
Jinchan Wang ◽  
Chunmin Zhang ◽  
Wenyi Ren ◽  
Lin Zhang ◽  
Junqiang Mao

2013 ◽  
Vol 52 (11) ◽  
pp. 2248 ◽  
Author(s):  
Jinchan Wang ◽  
Chunmin Zhang ◽  
Lin Zhang ◽  
Wenyi Ren ◽  
Xiaoke Sun

1999 ◽  
Vol 15 (2) ◽  
pp. 91-98 ◽  
Author(s):  
Lutz F. Hornke

Summary: Item parameters for several hundreds of items were estimated based on empirical data from several thousands of subjects. The logistic one-parameter (1PL) and two-parameter (2PL) model estimates were evaluated. However, model fit showed that only a subset of items complied sufficiently, so that the remaining ones were assembled in well-fitting item banks. In several simulation studies 5000 simulated responses were generated in accordance with a computerized adaptive test procedure along with person parameters. A general reliability of .80 or a standard error of measurement of .44 was used as a stopping rule to end CAT testing. We also recorded how often each item was used by all simulees. Person-parameter estimates based on CAT correlated higher than .90 with true values simulated. For all 1PL fitting item banks most simulees used more than 20 items but less than 30 items to reach the pre-set level of measurement error. However, testing based on item banks that complied to the 2PL revealed that, on average, only 10 items were sufficient to end testing at the same measurement error level. Both clearly demonstrate the precision and economy of computerized adaptive testing. Empirical evaluations from everyday uses will show whether these trends will hold up in practice. If so, CAT will become possible and reasonable with some 150 well-calibrated 2PL items.


2019 ◽  
Vol 24 (1) ◽  
pp. 70-91 ◽  
Author(s):  
Noémi K. Schuurman ◽  
Ellen L. Hamaker

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