|   | 
Details
   web
Records
Author (up) Bará, S., Lima, R.C.
Title Photons without borders: quantifying light pollution transfer between territories Type Journal Article
Year 2018 Publication International Journal of Sustainable Lighting Abbreviated Journal
Volume 20 Issue 2 Pages 51-61
Keywords Skyglow
Abstract The light pollution levels experienced at any given site generally depend on a wide number of artificial light sources distributed throughout the surrounding territory. Since photons can travel long distances before being scattered by the atmosphere, any effective proposal for reducing local light pollution levels needs an accurate assessment of the relative weight of all intervening light sources, including those located tens or even hundreds of km away. In this paper we describe several ways of quantifying and visualizing these relative weights. Particular emphasis is made on the aggregate contribution of the municipalities, which are -in many regions of the world- the administrative bodies primarily responsible for the planning and maintenance of public outdoor lighting systems.
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 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number NC @ ehyde3 @ Serial 2066
Permanent link to this record
 

 
Author (up) Bará, S., Ulla, A.
Title Light Pollution in the Galician Atlantic Islands Maritime-Terrestrial National Park 2018 Report Type Report
Year 2018 Publication Abbreviated Journal
Volume Issue Pages
Keywords Conservation; Spain; Galicia; Europe; national park
Abstract The Galician Atlantic Islands Maritime-Terrestrial National Park (PNMTIAG), with the exception of the island of Cortegada, still has night skies of acceptable quality. However, the PNMTIAG islands are under strong photic pressures, both internal and external, that hinder the preservation of the basic features of the natural night, and call for an immediate action of all concerned stakeholders
Address
Corporate Author Thesis
Publisher USC Tragsa Place of Publication Editor
Language Galician Summary Language Galician 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 2187
Permanent link to this record
 

 
Author (up) 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 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
Permanent link to this record
 

 
Author (up) Bará, S.; Escofet, J.
Title On lamps, walls, and eyes: The spectral radiance field and the evaluation of light pollution indoors Type Journal Article
Year 2018 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal J of Quant Spect and Rad Trans
Volume 205 Issue Pages 267-277
Keywords Instrumentation; Light pollution; Artificial light at night; Light field; Radiance field; Radiometry; Photometry
Abstract Light plays a key role in the regulation of different physiological processes, through several visual and non-visual retinal phototransduction channels whose basic features are being unveiled by recent research. The growing body of evidence on the significance of these effects has sparked a renewed interest in the determination of the light field at the entrance pupil of the eye in indoor spaces. Since photic interactions are strongly wavelength-dependent, a significant effort is being devoted to assess the relative merits of the spectra of the different types of light sources available for use at home and in the workplace. The spectral content of the light reaching the observer eyes in indoor spaces, however, does not depend exclusively on the sources: it is partially modulated by the spectral reflectance of the walls and surrounding surfaces, through the multiple reflections of the light beams along all possible paths from the source to the observer. This modulation can modify significantly the non-visual photic inputs that would be produced by the lamps alone, and opens the way for controlling—to a certain extent—the subject's exposure to different regions of the optical spectrum. In this work we evaluate the expected magnitude of this effect and we show that, for factorizable sources, the spectral modulation can be conveniently described in terms of a set of effective filter-like functions that provide useful insights for lighting design and light pollution assessment. The radiance field also provides a suitable bridge between indoor and outdoor light pollution studies.
Address Área de Óptica, Departamento de Física Aplicada, Universidade de Santiago de Compostela, Santiago de Compostela, Galicia, Spain; salva.bara(at)usc.es
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language English 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 IDA @ john @ Serial 2163
Permanent link to this record
 

 
Author (up) Bará, S.; Espey, B.; Falchi, F.; Kyba, C.C.M.; Nievas, M., Pescatori, P., Ribas, S.J., Sánchez de Miguel, A.; Staubmann, P., Tapia Ayuga, C.; Wuchterl, G., Zamorano, J.
Title Report of the 2014 LoNNe Intercomparison Campaign Type Report
Year 2015 Publication Abbreviated Journal
Volume Issue 32989 Pages
Keywords skyglow
Abstract The 2014 LoNNe (Loss of the Night Network) intercomparison campaign is the second of four campaigns planned during EU COST Action ES1204. The goal of these campaigns is to understand systematic uncertainty inherent in observations of skyglow (light pollution). An innovation of this year’s campaign was to take measurements with many of the nstruments at two sites: an urban location and a location far from artificial lights. This report summarizes the meeting, and also provides three recommendations for obtaining and analyzing handheld SQM observations.
Address
Corporate Author Thesis
Publisher Universidad Complutense Place of Publication Madrid Editor
Language English Summary Language English Original Title
Series Editor Series Title e-prints Complutense Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ kyba @ Serial 1254
Permanent link to this record