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Author Crumey, A.
Title Human Contrast Threshold and Astronomical Visibility. Type Journal Article
Year (up) 2014 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal MNRAS
Volume 422 Issue 3 Pages 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.; Solano Lamphar, H.A.
Title Quantitative analysis of night skyglow amplification under cloudy conditions Type Journal Article
Year (up) 2014 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal Monthly Notices of the Royal Astronomical Society
Volume 443 Issue 4 Pages 3665-3674
Keywords Skyglow; radiative transfer; scattering; atmospheric effects; light pollution; methods: numerical
Abstract The radiance produced by artificial light is a major source of nighttime over-illumination. It can, however, be treated experimentally using ground-based and satellite data. These two types of data complement each other and together have a high information content. For instance, the satellite data enable upward light emissions to be normalized, and this in turn allows skyglow levels at the ground to be modelled under cloudy or overcast conditions. Excessive night lighting imposes an unacceptable burden on nature, humans and professional astronomy. For this reason, there is a pressing need to determine the total amount of downwelling diffuse radiation. Undoubtedly, cloudy periods can cause a significant increase in skyglow as a result of amplification owing to diffuse reflection from clouds. While it is recognized that the amplification factor (AF) varies with cloud cover, the effects of different types of clouds, of atmospheric turbidity and of the geometrical relationships between the positions of an individual observer, the cloud layer, and the light source are in general poorly known. In this paper the AF is quantitatively analysed considering different aerosol optical depths (AODs), urban layout sizes and cloud types with specific albedos and altitudes. The computational results show that the AF peaks near the edges of a city rather than at its centre. In addition, the AF appears to be a decreasing function of AOD, which is particularly important when modelling the skyglow in regions with apparent temporal or seasonal variability of atmospheric turbidity. The findings in this paper will be useful to those designing engineering applications or modelling light pollution, as well as to astronomers and environmental scientists who aim to predict the amplification of skyglow caused by clouds. In addition, the semi-analytical formulae can be used to estimate the AF levels, especially in densely populated metropolitan regions for which detailed computations may be CPU-intensive. These new results are of theoretical and experimental significance as they will motivate experimentalists to collect data from various regions to build an overall picture of the AF, and will encourage modellers to test the consistency with theoretical predictions.
Address
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Publisher Place of Publication Editor
Language Summary Language Original Title
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ISSN 0035-8711 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ christopher.kyba @ Serial 538
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Author Edensor, T.; Falconer, E.
Title Dans Le Noir? Eating in the dark: sensation and conviviality in a lightless place Type Journal Article
Year (up) 2014 Publication Cultural Geographies Abbreviated Journal
Volume 22 Issue 4 Pages 601-618
Keywords Society; Darkness
Abstract Drawing on ethnographic interviews with customers, this paper looks at the experience of dining at Dans le Noir?, a restaurant in London where eating is carried out in complete darkness. As an exemplary gastro-tourist site within the expanding leisure economy at which sensory alterity is sought, we argue that the transformation of the usual unreflexive habits of sensing while dining offer opportunities to encounter difference and reflect upon our culturally located ways of sensing the world. In focusing upon the altered experience of apprehending space, eating and socialising in the absence of light, we contend that this dining experience offers broader suggestions about how we might reconsider the qualities and potentialities of darkness, a condition which has been historically feared and reviled in the west.
Address
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Publisher Place of Publication Editor
Language Summary Language Original Title
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ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ kagoburian @ Serial 740
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Author Fernández Sánchez, J. F.; Barranco R’ios, J.; Naráez Rueda, J. J.
Title Software de Medición Automatizada y Robótica de la Oscuridad del Cielo Type Conference Article
Year (up) 2014 Publication In Libro de actas del XXI Congreso Estatal de Astronom’ia Abbreviated Journal
Volume Issue Pages 205–209
Keywords Remote Sensing
Abstract
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Notes Approved no
Call Number LoNNe @ kagoburian @ Serial 936
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Author Posudin, Y. (n.d.)
Title Measurement of Light Pollution Type Journal Article
Year (up) 2014 Publication Methods of Measuring Environmental Parameters Abbreviated Journal
Volume Issue Pages 368-370
Keywords Skyglow
Abstract Digital photography is based on the conversion of light by sensitive matrix (array of electronic photodetectors) to capture the image which is then digitized and stored as a computer file for further processing and printing. The spectral sensitivity of the cameras is in good agreement with the spectrum of action of the photosensitive hormone melatonin. Digital photography can be used to quantify light pollution acting on the physiology of living organisms. The chapter discusses the principles of spectrophotometry. A portable spectrophotometer for the measurement of light pollution is proposed by Cinzano. It consists of a cooled CCDcamera and a small spectrographic head which is equipped with a De Amici prism composed of two external crown prisms and an inner Flint prism. Sky quality meter (SQM) is a portable photometer for measuring sky brightness and for light pollution monitoring. This device collects the light from a wide solid angle.
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Notes Approved no
Call Number LoNNe @ kagoburian @ Serial 967
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