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Author (up) Bará, S.; Nievas, M.; Sanchez de Miguel, A.; Zamorano, J.
Title Zernike analysis of all-sky night brightness maps Type Journal Article
Year 2014 Publication Applied Optics Abbreviated Journal Appl Opt
Volume 53 Issue 12 Pages 2677-2686
Keywords modeling; light at night; light pollution; all-sky; Zernike polynomials; image decomposition; sky brightness
Abstract All-sky night brightness maps (calibrated images of the night sky with hemispherical field-of-view (FOV) taken at standard photometric bands) provide useful data to assess the light pollution levels at any ground site. We show that these maps can be efficiently described and analyzed using Zernike circle polynomials. The relevant image information can be compressed into a low-dimensional coefficients vector, giving an analytical expression for the sky brightness and alleviating the effects of noise. Moreover, the Zernike expansions allow us to quantify in a straightforward way the average and zenithal sky brightness and its variation across the FOV, providing a convenient framework to study the time course of these magnitudes. We apply this framework to analyze the results of a one-year campaign of night sky brightness measurements made at the UCM observatory in Madrid.
Address Área de Óptica, Dept. de Física Aplicada, Fac. de Física, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Galicia, Spain
Corporate Author Thesis
Publisher Optical Society of America Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6935 ISBN Medium
Area Expedition Conference
Notes PMID:24787595 Approved no
Call Number IDA @ john @ Serial 318
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Author (up) Smith, G.; Vingrys, A.J.; Maddocks, J.D.; Hely, C.P.
Title Color recognition and discrimination under full-moon light Type Journal Article
Year 1994 Publication Applied Optics Abbreviated Journal Appl Opt
Volume 33 Issue 21 Pages 4741-4748
Keywords Human Health
Abstract The ability to recognize and discriminate colors under full-moon light was measured Color naming was performed at three sizes (0.5 degrees , 2 degrees , and 4 degrees ) by the use of one white and six colored chips that spanned the spectrum at two levels of saturation. The results show that correct color recognition is possible under full-moon light. However, the recognition rate depends on a complex interaction between hue, level of saturation, and size of test field. For small fields and desaturated colors, the recognition rate is low. However, for saturated colors, most hues can be recognized at better than chance levels, with red being recognized very accurately.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6935 ISBN Medium
Area Expedition Conference
Notes PMID:20935847 Approved no
Call Number LoNNe @ christopher.kyba @ Serial 531
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Author (up) Zukauskas, A.; Vaicekauskas, R.; Vitta, P.
Title Optimization of solid-state lamps for photobiologically friendly mesopic lighting Type Journal Article
Year 2012 Publication Applied Optics Abbreviated Journal Appl Opt
Volume 51 Issue 35 Pages 8423-8432
Keywords Lighting Systems; Circadian Rhythm; Color; Equipment Design; Humans; Light; *Lighting; Melatonin/metabolism; Photobiology/*methods; Semiconductors; Time Factors; Vision, Ocular
Abstract The circadian and visual-performance-based mesopic systems of photometry were applied for the optimization of the spectral power distributions (SPDs) of the solid-state sources of light for low-illuminance lighting applications. At mesopic adaptation luminances typical of outdoor lighting (0.1-2 cd/m(2)), the optimal SPDs were obtained through the minimization of the mesopic circadian action factor, which is the ratio of the circadian efficacy of radiation to mesopic luminous efficacy of radiation. For correlated color temperatures below ~3000 K, the optimized dichromatic light-emitting diodes (LEDs) are shown to pose a lower circadian hazard than high-pressure sodium lamps and common warm white LEDs; also they are potentially more efficacious and have acceptable color rendition properties under mesopic conditions.
Address Institute of Applied Research, Vilnius University, Sauletekio al. 9-III, Vilnius LT-10222, Lithuania. arturas.zukauskas@ff.vu.lt
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6935 ISBN Medium
Area Expedition Conference
Notes PMID:23262538 Approved no
Call Number LoNNe @ christopher.kyba @ Serial 448
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