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Author Kyba, C.C.M.; Ruhtz, T.; Fischer, J.; Hölker, F. url  doi
openurl 
  Title Red is the new black: how the colour of urban skyglow varies with cloud cover Type Journal Article
  Year 2012 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal Monthly Notices of the Royal Astronomical Society  
  Volume 425 Issue 1 Pages 701-708  
  Keywords Keywords: skyglow; radiative transfer; atmospheric effects; instrumentation: detectors; light pollution  
  Abstract The development of street lamps based on solid-state lighting technology is likely to introduce a major change in the colour of urban skyglow (one form of light pollution). We demonstrate the need for long-term monitoring of this trend by reviewing the influences it is likely to have on disparate fields. We describe a prototype detector which is able to monitor these changes, and could be produced at a cost low enough to allow extremely widespread use. Using the detector, we observed the differences in skyglow radiance in red, green and blue channels. We find that clouds increase the radiance of red light by a factor of 17.6, which is much larger than that for blue (7.1). We also find that the gradual decrease in sky radiance observed on clear nights in Berlin appears to be most pronounced at longer wavelengths.  
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  Series Volume Series Issue Edition  
  ISSN 0035-8711 ISBN Medium  
  Area Expedition Conference  
  Notes (up) Approved no  
  Call Number IDA @ john @ Serial 272  
Permanent link to this record
 

 
Author Kocifaj, M. url  doi
openurl 
  Title Two-stream approximation for rapid modeling the light pollution levels in local atmosphere Type Journal Article
  Year 2012 Publication Astrophysics and Space Science Abbreviated Journal Astrophys Space Sci  
  Volume 341 Issue 2 Pages 301-307  
  Keywords Light pollution; Atmospheric effects; Methods: numerical; Radiative transfer; Scattering; modeling; two-stream approximation  
  Abstract The two-stream concept is used for modeling the radiative transfer in Earth's atmosphere illuminated by ground-based light sources. The light pollution levels (illuminance and irradiance) are computed for various aerosol microphysical parameters, specifically the asymmetry parameter g A , single scattering albedo ω A , and optical thickness τ A . Two distinct size distributions of Junge's and gamma-type are employed. Rather then being a monotonic function of τ A , the diffuse illuminance/irradiance shows a local minimum at specific τ A, lim independent of size distribution taken into consideration. The existence of local minima has relation to the scattering and attenuation efficiencies both of which have opposite effects. The computational scheme introduced in this paper is advantageous especially if the entire set of calculations needs to be repeated with an aim to simulate diffuse light in various situations and when altering optical states of the atmospheric environment.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0004-640X ISBN Medium  
  Area Expedition Conference  
  Notes (up) Approved no  
  Call Number IDA @ john @ Serial 273  
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Author Kocifaj, M. url  doi
openurl 
  Title Light-pollution model for cloudy and cloudless night skies with ground-based light sources Type Journal Article
  Year 2007 Publication Applied Optics Abbreviated Journal Appl. Opt.  
  Volume 46 Issue 15 Pages 3013  
  Keywords light pollution; modeling  
  Abstract The scalable theoretical model of light pollution for ground sources is presented. The model is successfully employed for simulation of angular behavior of the spectral and integral sky radiance and∕or luminance during nighttime. There is no restriction on the number of ground-based light sources or on the spatial distribution of these sources in the vicinity of the measuring point (i.e., both distances and azimuth angles of the light sources are configurable). The model is applicable for real finite-dimensional surface sources with defined spectral and angular radiating properties contrary to frequently used point-source approximations. The influence of the atmosphere on the transmitted radiation is formulated in terms of aerosol and molecular optical properties. Altitude and spectral reflectance of a cloud layer are the main factors introduced for simulation of cloudy and∕or overcast conditions. The derived equations are translated into numerically fast code, and it is possible to repeat the entire set of calculations in real time. The parametric character of the model enables its efficient usage by illuminating engineers and∕or astronomers in the study of various light-pollution situations. Some examples of numerical runs in the form of graphical results are presented.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-6935 ISBN Medium  
  Area Expedition Conference  
  Notes (up) Approved no  
  Call Number IDA @ john @ Serial 277  
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Author Xavier Kerola, D. url  doi
openurl 
  Title Modelling artificial night-sky brightness with a polarized multiple scattering radiative transfer computer code: Modelling artificial night-sky brightness Type Journal Article
  Year 2006 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal  
  Volume 365 Issue 4 Pages 1295-1299  
  Keywords Skyglow; modeling; radiative transfer; Gauss-Seidel; light pollution; Garstang model  
  Abstract As part of an ongoing investigation of radiative effects produced by hazy atmospheres, computational procedures have been developed for use in determining the brightening of the night sky as a result of urban illumination. The downwardly and upwardly directed radiances of multiply scattered light from an offending metropolitan source are computed by a straightforward Gauss-Seidel (G-S) iterative technique applied directly to the integrated form of Chandrasekhar's vectorized radiative transfer equation. Initial benchmark night-sky brightness tests of the present G-S model using fully consistent optical emission and extinction input parameters yield very encouraging results when compared with the double scattering treatment of Garstang, the only full-fledged previously available model.  
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  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0035-8711 ISBN Medium  
  Area Expedition Conference  
  Notes (up) Approved no  
  Call Number IDA @ john @ Serial 278  
Permanent link to this record
 

 
Author Sweater-Hickcox, K.; Narendran, N.; Bullough, J.; Freyssinier, J. url  doi
openurl 
  Title Effect of different coloured luminous surrounds on LED discomfort glare perception Type Journal Article
  Year 2013 Publication Lighting Research and Technology Abbreviated Journal Lighting Research and Technology  
  Volume 45 Issue 4 Pages 464-475  
  Keywords perception; subjective; LED; LED lighting; spectral power distribution; SPD  
  Abstract Recently, there has been increased interest in energy-efficient lighting as energy resources become higher in demand. Anecdotal evidence suggests that certain populations believe light-emitting diodes (LED) produce more glare than traditional technologies. This may be due to a number of factors such as spectral power distribution (SPD), source luminance, or beam intensity distribution. A study was conducted to assess the effect of different SPDs on the perception of discomfort glare from an LED source. For the range of conditions evaluated, the presence of any luminous surround significantly reduced the perception of discomfort glare from the LED array. The blue luminous surround reduced discomfort glare perception significantly less than the white or the yellow luminous surrounds. The implications for solid-state lighting systems are discussed.  
  Address Lighting Research Center, Rensselaer Polytechnic Institute, Troy, NY, USA  
  Corporate Author Thesis  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1477-1535 ISBN Medium  
  Area Expedition Conference  
  Notes (up) Approved no  
  Call Number IDA @ john @ Serial 338  
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