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Author Cinzano, P.; Falchi, F. url  doi
openurl 
  Title Quantifying light pollution Type Journal Article
  Year 2014 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal Journal of Quantitative Spectroscopy and Radiative Transfer  
  Volume 139 Issue Pages 13-20  
  Keywords Atmospheric effects; Astronomical site testing; Scattering; Light pollution; Radiative transfer; Night sky brightness; Environmental pollution; Atmospheric pollution Corresponding author contact information  
  Abstract In this paper we review new available indicators useful to quantify and monitor light pollution, defined as the alteration of the natural quantity of light in the night environment due to introduction of manmade light. With the introduction of recent radiative transfer methods for the computation of light pollution propagation, several new indicators become available. These indicators represent a primary step in light pollution quantification, beyond the bare evaluation of the night sky brightness, which is an observational effect integrated along the line of sight and thus lacking the three-dimensional information.  
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  ISSN 0022-4073 ISBN Medium  
  Area Expedition Conference  
  Notes (up) Approved no  
  Call Number IDA @ john @ Serial 177  
Permanent link to this record
 

 
Author Luginbuhl, C.B.; Boley, P.A.; Davis, D.R. url  doi
openurl 
  Title The impact of light source spectral power distribution on sky glow Type Journal Article
  Year 2014 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal Journal of Quantitative Spectroscopy and Radiative Transfer  
  Volume 139 Issue Pages 21-26  
  Keywords Light pollution; Sky glow; Blue-rich light sources; LED; light emitting diode; lighting  
  Abstract The effect of light source spectral power distribution on the visual brightness of anthropogenic sky glow is described. Under visual adaptation levels relevant to observing the night sky, namely with dark-adapted (scotopic) vision, blue-rich (“white”) sources produce a dramatically greater sky brightness than yellow-rich sources. High correlated color temperature LEDs and metal halide sources produce a visual brightness up to 8× brighter than low-pressure sodium and 3× brighter than high-pressure sodium when matched lumen-for-lumen and observed nearby. Though the sky brightness arising from blue-rich sources decreases more strongly with distance, the visual sky glow resulting from such sources remains significantly brighter than from yellow sources out to the limits of this study at 300 km.  
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  ISSN 0022-4073 ISBN Medium  
  Area Expedition Conference  
  Notes (up) Approved no  
  Call Number IDA @ john @ Serial 178  
Permanent link to this record
 

 
Author Kolláth, Z.; Kránicz, B. url  doi
openurl 
  Title On the feasibility of inversion methods based on models of urban sky glow Type Journal Article
  Year 2014 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal Journal of Quantitative Spectroscopy and Radiative Transfer  
  Volume 139 Issue Pages 27-34  
  Keywords Light pollution; Radiative transfer; Light scattering  
  Abstract Multi-wavelength imaging luminance photometry of sky glow provides a huge amount of information on light pollution. However, the understanding of the measured data involves the combination of different processes and data of radiation transfer, atmospheric physics and atmospheric constitution. State-of-the-art numerical radiation transfer models provide the possibility to define an inverse problem to obtain information on the emission intensity distribution of a city and perhaps the physical properties of the atmosphere. We provide numerical tests on the solvability and feasibility of such procedures.  
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  ISSN 0022-4073 ISBN Medium  
  Area Expedition Conference  
  Notes (up) Approved no  
  Call Number IDA @ john @ Serial 179  
Permanent link to this record
 

 
Author Kocifaj, M. url  doi
openurl 
  Title Modeling the night-sky radiances and inversion of multi-angle and multi-spectral radiance data Type Journal Article
  Year 2014 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal Journal of Quantitative Spectroscopy and Radiative Transfer  
  Volume 139 Issue Pages 35-42  
  Keywords Sky-glow; Light pollution; Aerosols; Light scattering; Inverse problems  
  Abstract Information on a city's emission pattern is crucial for any reasonable predictions of night sky radiances. Unfortunately, the bulk radiant intensity distribution as a function of zenith angle is scarcely available for any city throughout the world. Even if the spatial arrangements of urban light fixtures and lamp specifications are known, the cumulative effect on upwardly directed beams is difficult to determine; due to heterogeneity of the ambient environment, reflectance from ground surfaces, arbitrarily scattered obstacles, orography of terrain and many other site specific factors.

The present paper develops a theoretical model and a numerical technique applicable to the retrieval of a City Emission Function (CEF) from the spectral sky radiances measured under clear sky conditions. Mathematically it is an inverse problem that is solved using a regularization algorithm in which the minimization routines penalize non-smooth solutions and the radiant intensity pattern is found subject to regularizing constraints.

When spectral sky radiances are measured at a set of discrete wavelengths or at a set of discrete distances from the monitored light source, both the aerosol optical properties and the CEF can be determined concurrently. One great advantage of this approach is that no a-priori assumptions need to be made concerning aerosol properties, such as aerosol optical depth.

The numerical experiment on synthetically generated city emissions' patterns has proven the functionality of the method presented.
 
  Address ICA, Slovak Academy of Sciences, Dúbravská Road 9, 845 03 Bratislava, Slovakia.  
  Corporate Author Thesis  
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  ISSN 0022-4073 ISBN Medium  
  Area Expedition Conference  
  Notes (up) Approved no  
  Call Number IDA @ john @ Serial 180  
Permanent link to this record
 

 
Author Kocifaj, M. url  doi
openurl 
  Title Night sky luminance under clear sky conditions: Theory vs. experiment Type Journal Article
  Year 2014 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal Journal of Quantitative Spectroscopy and Radiative Transfer  
  Volume 139 Issue Pages 43-51  
  Keywords Sky glow; Luminance; Luminaire; City emission function; Anthropogenic; Single scattering; Inverse problems  
  Abstract Sky glow is caused by both natural phenomena and factors of anthropogenic origin, and of the latter ground-based light sources are the most important contributors for they emit the spatially linked spectral radiant intensity distribution of artificial light sources, which are further modulated by local atmospheric optics and perceived as the diffuse light of a night sky. In other words, sky glow is closely related to a city's shape and pattern of luminaire distribution, in practical effect an almost arbitrary deployment of random orientation of heterogeneous electrical light sources. Thus the luminance gradation function measured in a suburban zone or near the edges of a city is linked to the City Pattern or vice versa.

It is shown that clear sky luminance/radiance data recorded in an urban area can be used to retrieve the bulk luminous/radiant intensity distribution if some a-priori information on atmospheric aerosols is available. For instance, the single scattering albedo of aerosol particles is required under low turbidity conditions, as demonstrated on a targeted experiment in the city of Frýdek-Mistek. One of the main advantages of the retrieval method presented in this paper is that the single scattering approximation is satisfactorily accurate in characterizing the light field near the ground because the dominant contribution to the sky glow has originated from beams propagated along short optical paths.
 
  Address ICA, Slovak Academy of Sciences, Dúbravská Road 9, 845 03 Bratislava, Slovakia  
  Corporate Author Thesis  
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  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-4073 ISBN Medium  
  Area Expedition Conference  
  Notes (up) Approved no  
  Call Number IDA @ john @ Serial 181  
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