| Records |
| Author |
Kocifaj, M.; Solano Lamphar, H.A. |
| Title |
Skyglow effects in UV and visible spectra: radiative fluxes |
Type |
Journal Article |
| Year |
2013 |
Publication |
Journal of Environmental Management |
Abbreviated Journal |
J Environ Manage |
| Volume |
127 |
Issue |
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Pages |
300-307 |
| Keywords |
Animals; Darkness; Environmental Exposure/*analysis; *Light; Models, Theoretical; *Ultraviolet Rays; Light pollution; Optical thickness; Public lighting system; Two stream approximation |
| Abstract |
Several studies have tried to understand the mechanisms and effects of radiative transfer under different night-sky conditions. However, most of these studies are limited to the various effects of visible spectra. Nevertheless, the invisible parts of the electromagnetic spectrum can pose a more profound threat to nature. One visible threat is from what is popularly termed skyglow. Such skyglow is caused by injudiciously situated or designed artificial night lighting systems which degrade desired sky viewing. Therefore, since lamp emissions are not limited to visible electromagnetic spectra, it is necessary to consider the complete spectrum of such lamps in order to understand the physical behaviour of diffuse radiation at terrain level. In this paper, the downward diffuse radiative flux is computed in a two-stream approximation and obtained ultraviolet spectral radiative fluxes are inter-related with luminous fluxes. Such a method then permits an estimate of ultraviolet radiation if the traditionally measured illuminance on a horizontal plane is available. The utility of such a comparison of two spectral bands is shown, using the different lamp types employed in street lighting. The data demonstrate that it is insufficient to specify lamp type and its visible flux production independently of each other. Also the UV emissions have to be treated by modellers and environmental scientists because some light sources can be fairly important pollutants in the near ultraviolet. Such light sources can affect both the living organisms and ambient environment. |
| Address |
ICA, Slovak Academy of Sciences, 9, Dubravska Road, 845 03 Bratislava, Slovak Republic. kocifaj@savba.sk |
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English |
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0301-4797 |
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PMID:23792881 |
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no |
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IDA @ john @ |
Serial |
265 |
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| Author |
Elvidge, C.D.; Keith, D.M.; Tuttle, B.T.; Baugh, K.E. |
| Title |
Spectral identification of lighting type and character |
Type |
Journal Article |
| Year |
2010 |
Publication |
Sensors (Basel, Switzerland) |
Abbreviated Journal |
Sensors (Basel) |
| Volume |
10 |
Issue |
4 |
Pages |
3961-3988 |
| Keywords |
Led; Nightsat; lighting efficiency; lighting types; nighttime lights; photopic band |
| Abstract |
We investigated the optimal spectral bands for the identification of lighting types and the estimation of four major indices used to measure the efficiency or character of lighting. To accomplish these objectives we collected high-resolution emission spectra (350 to 2,500 nm) for forty-three different lamps, encompassing nine of the major types of lamps used worldwide. The narrow band emission spectra were used to simulate radiances in eight spectral bands including the human eye photoreceptor bands (photopic, scotopic, and “meltopic”) plus five spectral bands in the visible and near-infrared modeled on bands flown on the Landsat Thematic Mapper (TM). The high-resolution continuous spectra are superior to the broad band combinations for the identification of lighting type and are the standard for calculation of Luminous Efficacy of Radiation (LER), Correlated Color Temperature (CCT) and Color Rendering Index (CRI). Given the high cost that would be associated with building and flying a hyperspectral sensor with detection limits low enough to observe nighttime lights we conclude that it would be more feasible to fly an instrument with a limited number of broad spectral bands in the visible to near infrared. The best set of broad spectral bands among those tested is blue, green, red and NIR bands modeled on the band set flown on the Landsat Thematic Mapper. This set provides low errors on the identification of lighting types and reasonable estimates of LER and CCT when compared to the other broad band set tested. None of the broad band sets tested could make reasonable estimates of Luminous Efficacy (LE) or CRI. The photopic band proved useful for the estimation of LER. However, the three photoreceptor bands performed poorly in the identification of lighting types when compared to the bands modeled on the Landsat Thematic Mapper. Our conclusion is that it is feasible to identify lighting type and make reasonable estimates of LER and CCT using four or more spectral bands with minimal spectral overlap spanning the 0.4 to 1.0 um region. |
| Address |
Earth Observation Group, Solar and Terrestrial Division, NOAA National Geophysical Data Center, 325 Broadway, Boulder, CO 80305, USA. chris.elvidge@noaa.gov |
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1424-8220 |
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PMID:22319336; PMCID:PMC3274255 |
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no |
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IDA @ john @ |
Serial |
275 |
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Johansson, M.; Pedersen, E.; Maleetipwan-Mattsson, P.; Kuhn, L.; Laike, T. |
| Title |
Perceived outdoor lighting quality (POLQ): A lighting assessment tool |
Type |
Journal Article |
| Year |
2013 |
Publication |
Journal of Environmental Psychology |
Abbreviated Journal |
Journal of Environmental Psychology |
| Volume |
39 |
Issue |
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Pages |
14-21 |
| Keywords |
Perception; Street lighting; Observation-based environmental assessment; Urban space |
| Abstract |
A shift towards more energy-efficient light sources for outdoor lighting such as light-emitting diodes (LEDs) is underway. Photometric measures are not sufficient to capture how users experience the light, so complementary tools are required. This study aimed to develop an observer-based environmental assessment tool, based on bipolar semantic differentials, for outdoor lighting in urban spaces. Exploratory (N = 130) and confirmatory (N = 117) factor analyses of observations of lighting installations made by laypersons on-site along pedestrian paths, resulted in two dimensions of high reliability: the Perceived Strength Quality (PSQ, Cronbach's alpha = 0.82–0.85) and the Perceived Comfort Quality (PCQ, Cronbach's alpha = 0.77–0.81). PSQ and PCQ differentiated between light sources of different illuminance level, colour temperature and colour rendering. Regression analyses showed that the perceived lighting qualities helped to explain the variance in visual accessibility, whereas PCQ helped to explain perceived danger in the environment. The perceived lighting qualities can add to the understanding of pedestrians' perception of outdoor lighting, and is proposed as a complementary tool for development of sustainable light designs in the urban environment. |
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| ISSN |
0272-4944 |
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no |
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IDA @ john @ |
Serial |
279 |
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| Author |
Kuhn, L.; Johansson, M.; Laike, T.; Goven, T. |
| Title |
Residents' perceptions following retrofitting of residential area outdoor lighting with LEDs |
Type |
Journal Article |
| Year |
2013 |
Publication |
Lighting Research and Technology |
Abbreviated Journal |
Lighting Research and Technology |
| Volume |
45 |
Issue |
5 |
Pages |
568-584 |
| Keywords |
*Lighting; outdoor lighting; LED; light emitting diode; lighting levels; public opinion |
| Abstract |
The use of light emitting diodes (LEDs) in outdoor lighting has energy-saving potential, but users’ responses to this light source are largely unknown. An intervention study in two residential areas compared conventional lighting installations (high pressure sodium in Area 1 and high pressure mercury in Area 2) to a retrofitted LED-alternative regarding residents’ perceptions of quality of light, visual accessibility and danger. Moreover, energy use was calculated. Residents’ (N = 60) visual accessibility improved and perceived danger remained low in both areas after retrofitting. In Area 2 the perceived quality of light increased, whereas in Area 1 the results were mixed. The retrofitted application reduced energy use by 41–76% and might be a feasible alternative to conventional outdoor lighting in relatively safe areas. |
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Environmental Psychology, Department of Architecture and Built Environment, Lund University, Lund, Sweden |
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1477-1535 |
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no |
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IDA @ john @ |
Serial |
280 |
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Zukauskas, A.; Vaicekauskas, R.; Tuzikas, A.; Petrulis, A.; Stanikunas, R.; Svegzda, A.; Eidikas, P.; Vitta, P. |
| Title |
Firelight LED Source: Toward a Balanced Approach to the Performance of Solid-State Lighting for Outdoor Environments |
Type |
Journal Article |
| Year |
2014 |
Publication |
IEEE Photonics Journal |
Abbreviated Journal |
IEEE Photonics J. |
| Volume |
6 |
Issue |
3 |
Pages |
1-16 |
| Keywords |
LED; lighting; lighting technology; light emitting diode; firelight LED |
| Abstract |
We report on a blue-amber (“firelightâ€) cluster of light-emitting diodes (LEDs) with extra-low correlated color temperature (~1860 K) optimized for outdoor lighting under mesopic conditions. When compared with common white LEDs, the firelight LED cluster shows considerably reduced indexes of melatonin suppression and skyglow, increased retinal illuminance for elderly people, but a reduced performance of perceiving colors, which, however, can be tolerated at mesopic luminance. In comparison with an almost metameric high-pressure sodium lamp, the cluster exhibits a potentially higher luminous efficacy, similar reaction time and detection threshold of luminance contrasts for achromatic targets, and noticeably improved color discrimination characteristics. |
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1943-0655 |
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IDA @ john @ |
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281 |
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