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Author Kolláth, Z. url  doi
openurl 
  Title Measuring and modelling light pollution at the Zselic Starry Sky Park Type Journal Article
  Year 2010 Publication Journal of Physics: Conference Series Abbreviated Journal J. Phys.: Conf. Ser.  
  Volume 218 Issue Pages (down) 012001  
  Keywords Skyglow; modeling; measurement; SQM; sky brightness; Zselic; International Dark Sky Park; Hungry; measurements; modeling; light pollution; skyglow; radiative transfer  
  Abstract One of the first 'International Dark-sky Parks' in Europe was established at the Zselic Landscape Protection Area in Hungary. A special monitoring program has been carrying on to survey the quality of the night sky using 'Sky Quality Meters' and DSLR cameras. The main conclusion of our measurements is that the local villages have only a minimal effect on the quality of the sky. There are light-domes due to the neighbouring cities only close to the horizon, the main source of obtrusive light is the city of Kaposvár. The anthropogenic component of zenith luminance of the night sky is obtained as the function of the distance from the city centre of Kaposvár. Our data were modelled by radiation transfer calculations. These results can help to draw attention to the energy emitted useless to the space and to protect our nocturnal landscape of nature parks for the next generations.  
  Address Konkoly Observatory, Konkoly Thege u. 15-17, H-1121 Budapest, Hungary; kollath(at)konkoly.hu  
  Corporate Author Thesis  
  Publisher IOP Place of Publication Editor  
  Language English Summary Language English Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1742-6596 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 1436  
Permanent link to this record
 

 
Author Zeng, C.; Zhou, Y.; Wang, S.; Yan, F.; Zhao, Q. url  doi
openurl 
  Title Population spatialization in China based on night-time imagery and land use data Type Journal Article
  Year 2011 Publication International Journal of Remote Sensing Abbreviated Journal International Journal of Remote Sensing  
  Volume 32 Issue 24 Pages (down) 9599-9620  
  Keywords DMSP-OLS; remote sensing; light at night; population; modeling  
  Abstract Population is a key indicator of socioeconomic development, urban planning and environmental protection, particularly for developing countries like China. But, census data for any given area are neither always available nor adequately reflect the internal differences of population. The authors tried to overcome this problem by spatializing the population across China through utilizing integer night-time imagery (Defense Meteorological Satellite Program/Operational Linescan System, DMSP/OLS) and land-use data. In creating the population linear regression model, night-time light intensity and lit areas, under different types of land use, were employed as predictor variables, and census data as dependent variables. To improve model performance, eight zones were created using night-time imagery clustering and shortest path algorithm. The population model is observed to have a coefficient of determination (R 2) ranging from 0.80 to 0.95 in the research area, which remained the same in different years. A comparison of the results of this study with those of other researchers shows that the spatialized population density map, prepared on the basis of night-time imagery, reflects the population distribution character more explicitly and in greater detail.  
  Address State Key Laboratory of Remote Sensing Science , Jointly Sponsored by the Institute of Remote Sensing Applications of the Chinese Academy of Sciences and Beijing Normal University , Beijing, 100101, PR China  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0143-1161 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 228  
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Author Kocifaj, M. url  doi
openurl 
  Title A numerical experiment on light pollution from distant sources: Light pollution from distant sources Type Journal Article
  Year 2011 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal MNRAS  
  Volume 415 Issue 4 Pages (down) 3609-3615  
  Keywords scattering; atmospheric effects; light pollution; methods: numerical; skyglow; modeling  
  Abstract To predict the light pollution of the night-time sky realistically over any location or measuring point on the ground presents quite a difficult calculation task. Light pollution of the local atmosphere is caused by stray light, light loss or reflection of artificially illuminated ground objects or surfaces such as streets, advertisement boards or building interiors. Thus it depends on the size, shape, spatial distribution, radiative pattern and spectral characteristics of many neighbouring light sources. The actual state of the atmospheric environment and the orography of the surrounding terrain are also relevant. All of these factors together influence the spectral sky radiance/luminance in a complex manner. Knowledge of the directional behaviour of light pollution is especially important for the correct interpretation of astronomical observations. From a mathematical point of view, the light noise or veil luminance of a specific sky element is given by a superposition of scattered light beams. Theoretical models that simulate light pollution typically take into account all ground-based light sources, thus imposing great requirements on CPU and MEM. As shown in this paper, a contribution of distant sources to the light pollution might be essential under specific conditions of low turbidity and/or Garstang-like radiative patterns. To evaluate the convergence of the theoretical model, numerical experiments are made for different light sources, spectral bands and atmospheric conditions. It is shown that in the worst case the integration limit is approximately 100 km, but it can be significantly shortened for light sources with cosine-like radiative patterns.  
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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 Approved no  
  Call Number IDA @ john @ Serial 267  
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Author Kocifaj, M.; Solano Lamphar, H.A. url  doi
openurl 
  Title Skyglow: a retrieval of the approximate radiant intensity function of ground-based light sources Type Journal Article
  Year 2014 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal Monthly Notices of the Royal Astronomical Society  
  Volume 439 Issue 4 Pages (down) 3405-3413  
  Keywords radiative transfer; atmospheric effects; light pollution; methods: observational; site testing; skyglow; modeling  
  Abstract The angular distribution of the light emitted from a city is an important source of information about public lighting systems and it also plays a key role in modelling the skyglow. Usually, the upwardly directed radiation is characterized through a parametrized emission function – a semi-empirical approach as a reasonable approximation that allows for fast computations. However, theoretical or experimental retrievals of emission characteristics are extremely difficult to obtain because of both the complexity of radiative transfer methods and/or the lack of highly specialized measuring devices.

Our research has been conducted with the specific objective to identify an efficient theoretical technique for retrieval of the emission pattern of ground-based light sources in order to determine the optimum values of the scaling parameters of the Garstang function. In particular, the input data involve the zenith luminance or radiance with horizontal illuminance or irradiance. Theoretical ratios of zenith luminance LV(0) to horizontal illuminance DV are calculated for a set of distances d that separate a hypothetical observer from the light source (a city or town). This approach is advantageous because inexpensive traditional equipment can be used to obtain the mean values of the Garstang parameters. Furthermore, it can also be applied to other parametrizable emission functions and to any measuring site, even one with a masked horizon.
 
  Address Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University, Mlynská dolina, 842 48 Bratislava, Slovak Republic  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  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 Approved no  
  Call Number IDA @ john @ Serial 326  
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Author Cinzano, P.; Falchi, F. url  doi
openurl 
  Title The propagation of light pollution in the atmosphere Type Journal Article
  Year 2012 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal Monthly Notices of the Royal Astronomical Society  
  Volume 427 Issue 4 Pages (down) 3337-3357  
  Keywords radiative transfer; scattering; atmospheric effects; light pollution; site testing; light at night; Garstang model; LPTRAN; DMSP-OLS; GTOPO30; modeling; propagation  
  Abstract Recent methods to map artificial night-sky brightness and stellar visibility across large territories or their distribution over the entire sky at any site are based on computation of the propagation of light pollution with Garstang models, a simplified solution of the radiative transfer problem in the atmosphere that allows fast computation by reducing it to a ray-tracing approach. They are accurate for a clear atmosphere, when a two-scattering approximation is acceptable, which is the most common situation. We present here up-to-date extended Garstang models (EGM), which provide a more general numerical solution for the radiative transfer problem applied to the propagation of light pollution in the atmosphere. We also present the LPTRAN software package, an application of EGM to high-resolution Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS) satellite measurements of artificial light emission and to GTOPO30 (Global 30 Arcsecond) digital elevation data, which provides an up-to-date method to predict the artificial brightness distribution of the night sky at any site in the world at any visible wavelength for a broad range of atmospheric situations and the artificial radiation density in the atmosphere across the territory. EGM account for (i) multiple scattering, (ii) wavelengths from 250 nm to infrared, (iii) the Earth's curvature and its screening effects, (iv) site and source elevation, (v) many kinds of atmosphere with the possibility of custom set-up (e.g. including thermal inversion layers), (vi) a mix of different boundary-layer aerosols and tropospheric aerosols, with the possibility of custom set-up, (vii) up to five aerosol layers in the upper atmosphere, including fresh and aged volcanic dust and meteoric dust, (viii) variations of the scattering phase function with elevation, (ix) continuum and line gas absorption from many species, ozone included, (x) up to five cloud layers, (xi) wavelength-dependent bidirectional reflectance of the ground surface from National Aeronautics and Space Administration (NASA) Moderate-Resolution Imaging Spectroradiometer (MODIS) satellite data, main models or custom data (snow included) and (xii) geographically variable upward light-emission function given as a three-parameter function or a Legendre polynomial series. Atmospheric scattering properties or light-pollution propagation functions from other sources can also be applied. A more general solution allows us to account also for (xiii) mountain screening, (xiv) geographical gradients of atmospheric conditions, including localized clouds and (xv) geographic distribution of ground surfaces, but suffers from too heavy computational requirements. Comparisons between predictions of classic Garstang models and EGM show close agreement for a US62 standard clear atmosphere and typical upward emission function.  
  Address  
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  Series Editor Series Title Abbreviated Series Title  
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  ISSN 0035-8711 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 271  
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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 (down) 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.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language 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 Approved no  
  Call Number IDA @ john @ Serial 277  
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Author Bará, S.; Nievas, M.; Sanchez de Miguel, A.; Zamorano, J. url  openurl
  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 (down) 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 Crumey, A. url  doi
openurl 
  Title Human Contrast Threshold and Astronomical Visibility. Type Journal Article
  Year 2014 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal MNRAS  
  Volume 422 Issue 3 Pages (down) 2600-2619  
  Keywords Vision; visibility; skyglow; sky brightness; modeling  
  Abstract The standard visibility model in light-pollution studies is the formula of Hecht, as used e.g. by Schaefer. However, it is applicable only to point sources and is shown to be of limited accuracy. A new visibility model is presented for uniform achromatic targets of any size against background luminances ranging from zero to full daylight, produced by a systematic procedure applicable to any appropriate data set (e.g. Blackwell's), and based on a simple but previously unrecognized empirical relation between contrast threshold and adaptation luminance. The scotopic luminance correction for variable spectral radiance (colour index) is calculated. For point sources, the model is more accurate than Hecht's formula and is verified using telescopic data collected at Mount Wilson in 1947, enabling the sky brightness at that time to be determined. The result is darker than the calculation by Garstang, implying that light pollution grew more rapidly in subsequent decades than has been supposed. The model is applied to the nebular observations of William Herschel, enabling his visual performance to be quantified. Proposals are made regarding sky quality indicators for public use.  
  Address Department of Humanities, Northumbria University, Newcastle upon Tyne NE1 8ST, UK; andrew.crumey(at)northumbria.ac.uk  
  Corporate Author Thesis  
  Publisher Oxford Journals Place of Publication Editor  
  Language English Summary Language English Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0035-8711 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number LoNNe @ christopher.kyba @ Serial 536  
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Author Kocifaj, M. url  doi
openurl 
  Title Modelling the spectral behaviour of night skylight close to artificial light sources Type Journal Article
  Year 2010 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal MNRAS  
  Volume 403 Issue 4 Pages (down) 2105-2110  
  Keywords scattering; atmospheric effects; light pollution; methods: numerical; Modeling  
  Abstract Spectral features of the night sky are simulated under cloudless conditions. Numerical runs show that spectral composition of the diffuse light changes over the whole sky and sky radiances quickly respond to altering aerosol characteristics, such as the asymmetry parameter, single scattering albedo and total optical thickness. The general trend is a steep decrease of diffuse irradiance with a distance from the city centre. Powerstar HQI-NDL lamps produce more light at short wavelengths, thus implying the higher levels of light pollution. The red light may markedly contribute to the obtrusive light if Vialox NAV-4Y lamps are considered as a prevailing source of light in the model town. In a non-turbid atmosphere, the minimum radiance is notoriously observed close to the zenith. As aerosol loading increases, the minimum radiance is shifted to larger zenith angles at the opposite side of the light source. Obtained results may serve as corrections to spectrophotometry data, as the light pollution can be easily calculated for any sky element and for any spectral band.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  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 Approved no  
  Call Number IDA @ john @ Serial 276  
Permanent link to this record
 

 
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 (down) 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.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  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 Approved no  
  Call Number IDA @ john @ Serial 278  
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