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Author Chen, H.; Sun, C.; Chen, X.; Chiang, K.; Xiong, X. url  doi
openurl 
  Title (up) 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 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  
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  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 1473  
Permanent link to this record
 

 
Author Scott, R. url  openurl
  Title (up) THE RELATIONSHIP BETWEEN ROAD LIGHTING QUALITY AND ACCIDENT FREQUENCY – TRRL LABORATORY REPORT 929. Type Journal Article
  Year 1980 Publication Abbreviated Journal  
  Volume 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  
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  Area Expedition Conference  
  Notes Approved no  
  Call Number LoNNe @ kagoburian @ Serial 647  
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Author Spitschan, M.; Aguirre, G.K.; Brainard, D.H.; Sweeney, A.M. url  doi
openurl 
  Title (up) 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 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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