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Author Aubé, M.
Title Physical behaviour of anthropogenic light propagation into the nocturnal environment Type Journal Article
Year 2015 Publication Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences Abbreviated Journal Philos Trans R Soc Lond B Biol Sci
Volume 370 Issue Pages (down) 20140117
Keywords Skyglow; artificial light at night; light pollution; radiative transfer; atmospheric effects; scattering; methods; numerical; sensitivity analysis
Abstract Propagation of artificial light at night (ALAN) in the environment is now known to have non negligible consequences on fauna, flora and human health. These consequences depend on light levels and their spectral power distributions, which in turn rely on the efficiency of various physical processes involved in the radiative transfer of this light into the atmosphere and its interactions with the built and natural environment. ALAN can affect the living organisms by direct lighting and indirect lighting (scattered by the sky and clouds and/or reflected by local surfaces). This paper mainly focuses on the behaviour of the indirect light scattered under clear sky conditions. Various interaction processes between anthropogenic light sources and the natural environment are discussed. This work mostly relies on a sensitivity analysis conducted with the light pollution radiative transfer model, Illumina (Aubé et al. 2005: Light pollution modelling and detection in a heterogeneous environment: toward a night-time aerosol optical depth retrieval method. In Proc. SPIE 2005, vol. 5890, San Diego, California, USA). More specifically, the impact of (i) the molecular and aerosol scattering and absorption, (ii) the second order of scattering, (iii) the topography and obstacle blocking, (iv) the ground reflectance and (v) the spectrum of light devices and their angular emission functions are examined. This analysis considers different behaviour as a function of the distance from the city centre, along with different zenith viewing angles in the principal plane.
Address Département de physique, Cégep de Sherbrooke, Sherbrooke, Quebec, Canada
Corporate Author Thesis
Publisher Royal Society Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title The biological impacts of artificial light at night: from molecules to communities Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 1115
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Author Linares, H.; Masana, E.; Ribas, S.J.; Aubé, M.; Simoneau, A.; Bará, S.
Title Night sky brightness simulation over Montsec protected area Type Journal Article
Year 2020 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal Journal of Quantitative Spectroscopy and Radiative Transfer
Volume 249 Issue Pages (down) 106990
Keywords Skyglow
Abstract Night sky brightness over Montsec Observatory (north-east of Spain) has been computed and checked against measurements using Illumina numerical model [2]. In a previous publication [20] the methodology was validated and light pollution received in the observatory coming from a unique city was computed. Here we present a simulation that includes all the sources that has a significant impact over the quality of the night sky in this area. The decision of which sources should be included in the simulations was taken following the methodology explained by [6]: using a point spread function (PSF) as a simple approach to estimate which sources are brightening the sky dome over the observer. An ad hoc PSF derived with Illumina was used with the purpose of avoiding to have to rely on already existing empirical PSF. The resulting PSF can be used in any location with similar atmospheric conditions. Differences in the spectrum of the lamps can be accounted easily by adjusting a spectrum scale factor. Illumina simulates the artificial sky brightness received (W/sr/m2) by an observer from any direction. Adding the natural sky brightness allows to compare the simulations to measurements taken with different instrumentation. In our case simulations were checked against ASTMON, SQC and SQM measurements. They show a good agreement both in absolute values and in geographical patterns for the three filters studied, B, V and R. The methodology presented opens many possibilities, such as increasing the reliability of the maps that point out the light pollution main contributors for any location, and reducing the amount of time needed to perform an accurate simulation of the night sky brightness.
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 0022-4073 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2923
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Author Aubé, M.; Roby, J.; Kocifaj, M.
Title Evaluating potential spectral impacts of various artificial lights on melatonin suppression, photosynthesis, and star visibility Type Journal Article
Year 2013 Publication PloS one Abbreviated Journal PLoS One
Volume 8 Issue 7 Pages (down) e67798
Keywords Humans; *Light; Lighting/methods; Melatonin/*metabolism; Photosynthesis/*radiation effects; Plant Development/radiation effects; blue light; circadian disruption
Abstract Artificial light at night can be harmful to the environment, and interferes with fauna and flora, star visibility, and human health. To estimate the relative impact of a lighting device, its radiant power, angular photometry and detailed spectral power distribution have to be considered. In this paper we focus on the spectral power distribution. While specific spectral characteristics can be considered harmful during the night, they can be considered advantageous during the day. As an example, while blue-rich Metal Halide lamps can be problematic for human health, star visibility and vegetation photosynthesis during the night, they can be highly appropriate during the day for plant growth and light therapy. In this paper we propose three new indices to characterize lamp spectra. These indices have been designed to allow a quick estimation of the potential impact of a lamp spectrum on melatonin suppression, photosynthesis, and star visibility. We used these new indices to compare various lighting technologies objectively. We also considered the transformation of such indices according to the propagation of light into the atmosphere as a function of distance to the observer. Among other results, we found that low pressure sodium, phosphor-converted amber light emitting diodes (LED) and LED 2700 K lamps filtered with the new Ledtech's Equilib filter showed a lower or equivalent potential impact on melatonin suppression and star visibility in comparison to high pressure sodium lamps. Low pressure sodium, LED 5000 K-filtered and LED 2700 K-filtered lamps had a lower impact on photosynthesis than did high pressure sodium lamps. Finally, we propose these indices as new standards for the lighting industry to be used in characterizing their lighting technologies. We hope that their use will favor the design of new environmentally and health-friendly lighting technologies.
Address Departement de physique, Cegep de Sherbrooke, Sherbrooke, Quebec, Canada. martin.aube@cegepsherbrooke.qc.ca
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 1932-6203 ISBN Medium
Area Expedition Conference
Notes PMID:23861808; PMCID:PMC3702543 Approved no
Call Number IDA @ john @ Serial 282
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Author Simoneau, A.; Aubé, M.; Bertolo, A.
Title Multispectral analysis of the night sky brightness and its origin for the Asiago Observatory, Italy Type Journal Article
Year 2020 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal MNRAS
Volume 491 Issue 3 Pages (down) 4398-4405
Keywords Skyglow; light pollution; numerical methods; Site testing; Italy; Observatories
Abstract Night protection has been a major concern for astronomers since the electrification of cities and is beginning to be recognized as a major environmental problem. In recent years, regulations have been put in place through the establishment of Dark Sky Reserves that impose stringent constraints on lighting practices for cities in protected areas. Astronomers from the Asiago Observatory, located in the Veneto region of Italy, would like to create an area of this nature around their facilities to improve and protect the quality of their astronomical observations. This study assesses the current state of the sky in the region through numerical modelling using the latest improvements to the ILLUMINA model and aims to identify the main contributing sources of artificial light. The explicit calculation of the contribution of private residential lighting helps to discern the origin of the light. We also present a new approach for extracting an estimate of the distribution of lamp technology in a region from images taken from the International Space Station.
Address Bishop’s University, 2600 rue College, Sherbrooke, Québec J1M 1Z7, Canada; alsimoneau(at)gmail.com
Corporate Author Thesis
Publisher Oxford Academic 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 IDA @ john @ Serial 2790
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Author Sánchez de Miguel, A.; Aubé, M.; Zamorano, J.; Kocifaj, M.; Roby, J.; Tapia, C.
Title Sky Quality Meter measurements in a colour-changing world Type Journal Article
Year 2017 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal
Volume 467 Issue 3 Pages (down) 2966-2979
Keywords skyglow
Abstract The Sky Quality Meter (SQM) has become the most common device used to track the evolution of the brightness of the sky from polluted regions to first-class astronomical observatories. A vast database of SQM measurements already exists for many places in the world. Unfortunately, the SQM operates over a wide spectral band and its spectral response interacts with the sky's spectrum in a complex manner. This is why the optical signals are difficult to interpret when the data are recorded in regions with different sources of artificial light. The brightness of the night sky is linked in a complex way to ground-based light emissions, while taking into account atmospheric-induced optical distortion as well as spectral transformation from the underlying ground surfaces. While the spectral modulation of the sky's radiance has been recognized, it still remains poorly characterized and quantified. The impact of the SQM's spectral characteristics on sky-brightness measurements is analysed here for different light sources, including low- and high-pressure sodium lamps, PC-amber and white LEDs, metal halide and mercury lamps. We show that a routine conversion of radiance to magnitude is difficult, or rather impossible, because the average wavelength depends on actual atmospheric and environment conditions, the spectrum of the source and device-specific properties. We correlate SQM readings with both the Johnson astronomical photometry bands and the human system of visual perception, assuming different lighting technologies. These findings have direct implications for the processing of SQM data and for their improvement and/or remediation.
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 LoNNe @ kyba @ Serial 1734
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Author Bará, S.; Aubé, M.; Barentine, J.; Zamorano, J.
Title Magnitude to luminance conversions and visual brightness of the night sky Type Journal Article
Year 2020 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal MNRAS
Volume 493 Issue 2 Pages (down) 2429–2437
Keywords Skyglow; light pollution; atmospheric effects; techniques: photometric; methods: numerical; luminance
Abstract The visual brightness of the night sky is not a single-valued function of its brightness in other photometric bands, because the transformations between photometric systems depend on the spectral power distribution of the skyglow. We analyze the transformation between the night sky brightness in the Johnson-Cousins V band (mV, measured in magnitudes per square arcsecond, mpsas) and its visual luminance (L, in SI units cd m−2) for observers with photopic and scotopic adaptation, in terms of the spectral power distribution of the incident light. We calculate the zero-point luminances for a set of skyglow spectra recorded at different places in the world, including strongly light-polluted locations and sites with nearly pristine natural dark skies. The photopic skyglow luminance corresponding to mV = 0.00 mpsas is found to vary between 1.11–1.34 × 105 cd m−2 if mV is reported in the absolute (AB) magnitude scale, and between 1.18–1.43 × 105 cd m−2 if a Vega scale for mV is used instead. The photopic luminance for mV = 22.0 mpsas is correspondingly comprised between 176 and 213 μcd m−2 (AB), or 187 and 227 μcd m−2 (Vega). These constants tend to decrease for increasing correlated color temperatures (CCT). The photopic zero-point luminances are generally higher than the ones expected for blackbody radiation of comparable CCT. The scotopic-to-photopic luminance ratio (S/P) for our spectral dataset varies from 0.8 to 2.5. Under scotopic adaptation the dependence of the zero-point luminances with the CCT, and their values relative to blackbody radiation, are reversed with respect to photopic ones.
Address Departamento de Física Aplicada, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Galicia; salva.bara(at)usc.gal
Corporate Author Thesis
Publisher Oxford Academic Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 2825
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Author Aubé, M.; Simoneau, A.; Wainscoat, R.; Nelson, L.
Title Modeling the effects of phosphor converted LED lighting to the night sky of the Haleakala Observatory, Hawaii Type Journal Article
Year 2018 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal
Volume 478 Issue 2 Pages (down) 1776-1783
Keywords Skyglow
Abstract The goal of this study is to evaluate the current level of light pollution in the night sky at the Haleakala Observatory on the island of Maui in Hawaii. This is accomplished with a numerical model that was tested in the first International Dark Sky Reserve located in Mont-Mégantic National Park in Canada. The model uses ground data on the artificial light sources present in the region of study, geographical data, and remotely sensed data for: 1) the nightly upward radiance; 2) the terrain elevation; and, 3) the ground spectral reflectance of the region. The results of the model give a measure of the current state of the sky spectral radiance at the Haleakala Observatory. Then, using the current state as a reference point, multiple light conversion plans are elaborated and evaluated using the model. We can thus estimate the expected impact of each conversion plan on the night sky radiance spectrum. A complete conversion to white (LEDs) with (CCT) of 4000K and 3000K are contrasted with a conversion using (PC) amber (LEDs). We include recommendations concerning the street lamps to be used in sensitive areas like the cities of Kahului and Kihei and suggest best lighting practices related to the color of lamps used at night.
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 GFZ @ kyba @ Serial 1907
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Author Kocifaj, M.; Aubé, M.; Kohút, I.
Title The effect of spatial and spectral heterogeneity of ground-based light sources on night-sky radiances: Light pollution for heterogeneous sources Type Journal Article
Year 2010 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal
Volume 409 Issue 3 Pages (down) 1203-1212
Keywords light pollution; scattering; atmospheric effects; methods: numerical
Abstract Nowadays, light pollution is a permanent problem at many observatories around the world. Elimination of excessive lighting during the night is not only about reduction of the total luminous power of ground-based light sources, but also involves experimenting with the spectral features of single lamps. Astronomical photometry is typically made at specific wavelengths, and thus the analysis of the spectral effects of light pollution is highly important. Nevertheless, studies on the spectral behaviour of night light are quite rare. Instead, broad-band or integral quantities (such as sky luminance) are preferentially measured and modelled. The knowledge of night-light spectra is necessary for the proper interpretation of narrow-band photometry data. In this paper, the night-sky radiances in the nominal spectral lines of the B (445 nm) and V (551 nm) filters are determined numerically under clear-sky conditions. Simultaneously, the corresponding sky-luminance patterns are computed and compared against the spectral radiances. It is shown that spectra, patterns and distances of the most important light sources (towns) surrounding an observatory are essential for determining the light pollution levels. In addition, the optical characteristics of the local atmosphere can change the angular behaviour of the sky radiance or luminance. All these effects are evaluated for two Slovakian observatories: Stará Lesná and Vartovka.
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 259
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Author Aubé, M.; Kocifaj, M.
Title Using two light-pollution models to investigate artificial sky radiances at Canary Islands observatories: Light-pollution models and artificial sky radiances Type Journal Article
Year 2012 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal
Volume 422 Issue 1 Pages (down) 819-830
Keywords Keywords: radiative transfer; atmospheric effects; light pollution; methods: observational; site testing
Abstract Astronomical observations are increasingly limited by light pollution, which is a product of the over-illumination of the night sky. To predict both the angular distribution of scattered light and the ground-reaching radiative fluxes, a set of models has been introduced in recent decades. Two distinct numerical tools, MSNsRAu and ILLUMINA, are compared in this paper, with the aim of identifying their strengths and weaknesses. The numerical experiment comprises the simulation of spectral radiances in the region of the Canary Islands. In particular, the light fields near the Roque de los Muchachos and Teide observatories are computed under various turbidity conditions. It is shown that ILLUMINA has enhanced accuracy at low elevation angles. However, ILLUMINA is time-consuming because of the two scattering orders incorporated into the calculation scheme. Under low-turbidity conditions and for zenith angles smaller than 70° the two models agree well, and thus can be successfully applied to typical cloudless situations at the majority of observatories. MSNsRAu is well optimized for large-scale simulations. In particular, the grid size is adapted dynamically depending on the distance between a light source and a hypothetical observer. This enables rapid numerical modelling for large territories. MSNsRAu is also well suited for the mass modelling of night-sky radiances after ground-based light sources are hypothetically changed. This enables an optimum design of public lighting systems and a time-efficient evaluation of the optical effects related to different lamp spectra or different lamp distributions. ILLUMINA provides two diagnostic geographical maps to help local authorities concerned about light-pollution control. The first map allows the identification of the relative contribution of each ground element to the observed sky radiance at a given viewing angle, while the second map gives the sensitivity, basically saying how each ground element contributes per lumen installed.
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 256
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Author Hänel, A.; Posch, T.; Ribas, S.J.; Aubé, M.; Duriscoe, D.; Jechow, A.; Kollath, Z.; Lolkema, D.E.; Moore, C.; Schmidt, N.; Spoelstra, H.; Wuchterl, G.; Kyba, C.C.M.
Title Measuring night sky brightness: methods and challenges Type Journal Article
Year 2018 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal Journal of Quantitative Spectroscopy and Radiative Transfer
Volume 205 Issue Pages (down) 278-290
Keywords skyglow
Abstract Measuring the brightness of the night sky has become an increasingly important topic in recent years, as artificial lights and their scattering by the Earthâ??s atmosphere continue spreading around the globe. Several instruments and techniques have been developed for this task. We give an overview of these, and discuss their strengths and limitations. The different quantities that can and should be derived when measuring the night sky brightness are discussed, as well as the procedures that have been and still need to be defined in this context. We conclude that in many situations, calibrated consumer digital cameras with fisheye lenses provide the best relation between ease-of-use and wealth of obtainable information on the night sky. While they do not obtain full spectral information, they are able to sample the complete sky in a period of minutes, with colour information in three bands. This is important, as given the current global changes in lamp spectra, changes in sky radiance observed only with single band devices may lead to incorrect conclusions regarding long term changes in sky brightness. The acquisition of all-sky information is desirable, as zenith-only information does not provide an adequate characterization of a site. Nevertheless, zenith-only single-band one-channel devices such as the â??Sky Quality Meterâ? continue to be a viable option for long-term studies of night sky brightness and for studies conducted from a moving platform. Accurate interpretation of such data requires some understanding of the colour composition of the sky light. We recommend supplementing long-term time series derived with such devices with periodic all-sky sampling by a calibrated camera system and calibrated luxmeters or luminance meters.
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 0022-4073 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ kyba @ Serial 1731
Permanent link to this record