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Proceedings Paper

Numerical computation of modulated factor in measuring D*
Author(s): Xiangrong He; Yan Zhang; Yani Zhang; Hengjing Tang
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Paper Abstract

The "direct current" radiation is turned to periodic "alternating current" radiation by the modulate tray, then, the periodic "alternating current" radiation is received by photoelectric detector in one constant frequency during measuring D*. The ratio is called modulated factor, which the ratio is the fundamental virtual factor of "alternating current" radiant power to "direct current" radiant power. The modulated factor is an important parameter in measuring D*. The modulated factor could be gained by analytic method or numerical computation method. In this paper, by the method of numerical computation and Matlab program, the authors give out modulated factor of a light-spot modulated by a fan-shaped modulate tray. The modulated factor is different from r, R, n. Some conclusions that we are using in measuring D* are testified. When the light-spot and the detector are at the same axis and L≥10 √Ab (Ab is the area of the light-spot), the diameter of the light-spot is 0.87 of the width of fan-shaped modulate tray dentition, the modulated factor is 0.3536.

Paper Details

Date Published: 4 August 2009
PDF: 6 pages
Proc. SPIE 7383, International Symposium on Photoelectronic Detection and Imaging 2009: Advances in Infrared Imaging and Applications, 738316 (4 August 2009); doi: 10.1117/12.835707
Show Author Affiliations
Xiangrong He, Shanghai Institute of Technical Physics (China)
Yan Zhang, Shanghai Institute of Technical Physics (China)
Yani Zhang, Shanghai Institute of Technical Physics (China)
Hengjing Tang, Shanghai Institute of Technical Physics (China)


Published in SPIE Proceedings Vol. 7383:
International Symposium on Photoelectronic Detection and Imaging 2009: Advances in Infrared Imaging and Applications
Jeffery Puschell; Hai-mei Gong; Yi Cai; Jin Lu; Jin-dong Fei, Editor(s)

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