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Author Horvath, H. url  doi
openurl 
  Title (up) Basic optics, aerosol optics, and the role of scattering for sky radiance Type Journal Article
  Year 2014 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal Journal of Quantitative Spectroscopy and Radiative Transfer  
  Volume 139 Issue Pages 3-12  
  Keywords Light extinction; Scattering function; Atmospheric radiance; Ground reflectivity; Color effects  
  Abstract The radiance of the night sky is determined by the available light and the scattering properties of the atmosphere (particles and gases). The scattering phase function of the aerosol has a strong dependence on the scattering angle, and depending on the viewing direction different parts of the atmosphere and the ground reflectivity give the most important contribution. The atmospheric radiance cannot be altered by optical instruments. On the other hand the light flux of a distant star increases with the size of the telescope, thus fainter stars become visible. Light extinction, scattering function, atmospheric radiance, ground reflectivity, color effects and others are discussed in detail and a simple theoretical treatment is given.  
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  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 176  
Permanent link to this record
 

 
Author Galadí-Enríquez, D. url  doi
openurl 
  Title (up) Beyond CCT: The spectral index system as a tool for the objective, quantitative characterization of lamps Type Journal Article
  Year 2018 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal JQSRT  
  Volume 206 Issue Pages 399-408  
  Keywords Lighting  
  Abstract Correlated color temperature (CCT) is a semi-quantitative system that roughly describes the spectra of lamps. This parameter gives the temperature (measured in kelvins) of the black body that would show the hue more similar to that of the light emitted by the lamp. Modern lamps for indoor and outdoor lighting display many spectral energy distributions, most of them extremely different to those of black bodies, what makes CCT to be far from a perfect descriptor from the physical point of view. The spectral index system presented in this work provides an accurate, objective, quantitative procedure to characterize the spectral properties of lamps, with just a few numbers. The system is an adaptation to lighting technology of the classical procedures of multi-band astronomical photometry with wide and intermediate-band filters. We describe the basic concepts and we apply the system to a representative set of lamps of many kinds. The results lead to interesting, sometimes surprising conclusions. The spectral index system is extremely easy to implement from the spectral data that are routinely measured at laboratories. Thus, including this kind of computations in the standard protocols for the certification of lamps will be really straightforward, and will enrich the technical description of lighting devices.  
  Address  
  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 GFZ @ kyba @ Serial 1835  
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Author Fiorentin, P.; Bertolo, A.; Cavazzani, S.; Ortolani, S. url  doi
openurl 
  Title (up) Calibration of digital compact cameras for sky quality measures Type Journal Article
  Year 2020 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal Journal of Quantitative Spectroscopy and Radiative Transfer  
  Volume in press Issue Pages  
  Keywords Skyglow; Instrumentation  
  Abstract This work presents the possibility of using the extremely popular compact digital cameras of smartphones or action cameras to perform sky photometry. The newest generation of these devices allows to save raw images. They are not as good as digital single-lens reflex camera, in particular in terms of sensitivity, noise and pixel depth (10 bit versus 12 bit or more), but they have the advantage of being extremely widespread on the population and relatively cheap. These economical digital compact cameras work with an electronic shutter, it overcomes the consumption of mechanics and allows to gather images for long time. The work uses a simple calibration method to transfer raw data from the proprietary RGB color space to the standard CIE 1931 color space. It allows the measurement of sky luminance in cd m−2 with an expected uncertainty of about 20%. Furthermore, the colorimetric calibration allows to know the correlated color temperature of a portion of the sky, it can help the identification of the kind of polluting sources. Aiming at better clarifying the performances of calibrated digital compact cameras, a comparison with a calibrated DSLR camera is presented in outdoor situations showing a good agreement both for luminance and color temperature measurements.  
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  ISSN 0022-4073 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 3063  
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Author Pun, C.S.J.; So, C.W.; Leung, W.Y.; Wong, C.F. url  doi
openurl 
  Title (up) Contributions of artificial lighting sources on light pollution in Hong Kong measured through a night sky brightness monitoring network Type Journal Article
  Year 2014 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal Journal of Quantitative Spectroscopy and Radiative Transfer  
  Volume 139 Issue Pages 90-108  
  Keywords Light pollution; Night sky brightness; Skyglow; Moon radiation; Urban lighting; Hong Kong  
  Abstract Light pollution is a form of environmental degradation in which excessive artificial outdoor lighting, such as street lamps, neon signs, and illuminated signboards, affects the natural environment and the ecosystem. Poorly designed outdoor lighting not only wastes energy, money, and valuable Earth resources, but also robs us of our beautiful night sky. Effects of light pollution on the night sky can be evaluated by the skyglow caused by these artificial lighting sources, through measurements of the night sky brightness (NSB). The Hong Kong Night Sky Brightness Monitoring Network (NSN) was established to monitor in detail the conditions of light pollution in Hong Kong. Monitoring stations were set up throughout the city covering a wide range of urban and rural settings to continuously measure the variations of the NSB. Over 4.6 million night sky measurements were collected from 18 distinct locations between May 2010 and March 2013. This huge dataset, over two thousand times larger than our previous survey [1], forms the backbone for studies of the temporal and geographical variations of this environmental parameter and its correlation with various natural and artificial factors. The concepts and methodology of the NSN were presented here, together with an analysis of the overall night sky conditions in Hong Kong. The average NSB in Hong Kong, excluding data affected by the Moon, was 16.8 mag arcsec−2, or 82 times brighter than the dark site standard established by the International Astronomical Union (IAU) [2]. The urban night sky was on average 15 times brighter than that in a rural location, firmly establishing the effects of artificial lighting sources on the night sky.  
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  Series Editor Series Title Abbreviated Series Title  
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  ISSN 0022-4073 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 186  
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Author Massetti, L. url  doi
openurl 
  Title (up) Drivers of artificial light at night variability in urban, rural and remote areas Type Journal Article
  Year 2020 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal Journal of Quantitative Spectroscopy and Radiative Transfer  
  Volume in press Issue Pages  
  Keywords Skyglow  
  Abstract Light pollution generated by the excessive use of artificial light at night is an environmental and ecological concern. Artificial light at night is diffused far from the sources, for long distances by scattering in the atmosphere (skyglow), thus affecting the night sky and the biodiversity of rural and natural areas. The characterization of the level and variability of light pollution has become an important issue for several disciplines.

This study analyzes light pollution in urban, rural and remote sites in Tuscany (Italy) by monitoring night sky brightness. Night sky brightness (NSB) data collected from 2016 to 2019 were analyzed to assess annual and seasonal variability at each site and between sites. The relationship between night sky brightness and moonlight and weather conditions were also analyzed. Trend analysis was also performed to evaluate the degradation of the quality of the measurement with time due to dirty accumulation on the sensor shield.

NSB in Tuscany during moonless nights ranged between 17.3 and 21.8 mpsas. The monthly cycle of moonlight is the main driver of night sky brightness variability in the remote site (21.8 mpsas on moonless nights and 18.5 mpsas on full moon nights) with a slight, but significant darkening effect during rainy conditions (22.3 mpsas). In urban sites, moonlight cycle is almost completely masked by weather conditions, as it can be seen from the analysis of seasonal variability, lunar monthly cycle analysis and weather condition analysis. Average night sky brightness on rainy days might reach 15.4 mpsas (approximately 436 times brighter than the natural background), an intensity that is even higher than average night sky brightness in full moonlight at the same site (16.6 mpsas). Light pollution can reach levels that might affect nocturnal species, and therefore the study of long term variability of light pollution is important for ecological studies.
 
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  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 GFZ @ kyba @ Serial 3069  
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