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Author Spitschan, M.; Aguirre, G.K.; Brainard, D.H.; Sweeney, A.M.
Title Variation of outdoor illumination as a function of solar elevation and light pollution Type Journal Article
Year 2016 Publication Scientific Reports Abbreviated Journal Sci Rep
Volume (down) 6 Issue Pages 26756
Keywords Skyglow; Measurements; light pollution; daylight; twilight; sky brightness; spectral irradiance; CIE
Abstract The illumination of the environment undergoes both intensity and spectral changes during the 24 h cycle of a day. Daylight spectral power distributions are well described by low-dimensional models such as the CIE (Commission Internationale de l'Eclairage) daylight model, but the performance of this model in non-daylight regimes is not characterised. We measured downwelling spectral irradiance across multiple days in two locations in North America: One rural location (Cherry Springs State Park, PA) with minimal anthropogenic light sources, and one city location (Philadelphia, PA). We characterise the spectral, intensity and colour changes and extend the existing CIE model for daylight to capture twilight components and the spectrum of the night sky.
Address Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
Corporate Author Thesis
Publisher Nature Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2045-2322 ISBN Medium
Area Expedition Conference
Notes PMID:27272736 Approved no
Call Number IDA @ john @ Serial 1464
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Author Scott, R.
Title THE RELATIONSHIP BETWEEN ROAD LIGHTING QUALITY AND ACCIDENT FREQUENCY – TRRL LABORATORY REPORT 929. Type Journal Article
Year 1980 Publication Abbreviated Journal
Volume (down) Issue Pages
Keywords Lighting; quality; accident rate; accident; frequency; luminance; glare; uniformity; urban area; daylight; darkness; surfacing; pedestrian
Abstract many studies have related changes in accident frequency to the presence of street lighting, and a few have examined its variation over a range of lighting quality, as measured by illuminance. this investigation attempts to find which of several measures of lighting (describing quantity – as represented by luminance or illuminance – uniformity and glare) most clearly explain variations in accident frequency. about 100 lit sites, almost all in built-up areas, were measured for lighting quality in dry-road conditions. the lighting variables measured were related to the dark:day ratios of accident frequency for the same sites. the strongest relationship found was that for average road surface luminance: in the range 0.5-2.0 candelas/m2, it is estimated that an increase of 1 cd/m2 is associated with a 35 per cent lower accident ratio. other measures of luminance and illuminance were also found to be related to accident ratio (and to each other), but not as clearly as was average road luminance, which is therefore the preferred explanatory variable. analysis of pedestrian and non-pedestrian accidents separately did not reveal a relationship between the former and lighting quality. in contrast, non-pedestrian accidents showed similar relationships to those for all accidents, with the addition of a possible relationship with overall uniformity of luminance.(a)
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 LoNNe @ kagoburian @ Serial 647
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Author Chen, H.; Sun, C.; Chen, X.; Chiang, K.; Xiong, X.
Title On-orbit calibration and performance of S-NPP VIIRS DNB Type Conference Article
Year 2016 Publication Proc. SPIE 9881, Earth Observing Missions and Sensors: Development, Implementation, and Characterization IV, 98812B (May 2, 2016) Abbreviated Journal Proc. SPIE 9881
Volume (down) Issue Pages
Keywords Remote Sensing; VIIRS, Suomi; VIIRS DNB; day-night band; calibration; Land Science Investigator-led Processing Systems; SIPS; Orbital dynamics; Sensors; Stray light; Contamination; Diffusers; Earth sciences; Equipment and services
Abstract The S-NPP VIIRS instrument has successfully operated since its launch in October 2011. The VIIRS Day-Night Band (DNB) is a panchromatic channel covering wavelengths from 0.5 to 0.9 μm that is capable of observing Earth scenes during both day and nighttime orbits at a spatial resolution of 750 m. To cover the large dynamic range, the DNB operates at low, mid, or high gain stages, and it uses an onboard solar diffuser (SD) for its low gain stage calibration. The SD observations also provide a means to compute gain ratios of low-to-mid and mid-to-high gain stages. This paper describes the DNB on-orbit calibration methodologies used by the VIIRS Characterization Support Team (VCST) in supporting the NASA earth science community with consistent VIIRS sensor data records (SDRs) made available by the Land Science Investigator-led Processing Systems (SIPS). It provides an assessment and update of DNB on-orbit performance, including the SD degradation in the DNB spectral range, detector gain and gain ratio trending, stray light contamination and its correction. Also presented in this paper are performance validations based on earth scenes and lunar observations.
Address Science Systems and Applications, Inc.
Corporate Author Thesis
Publisher SPIE 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 1473
Permanent link to this record