toggle visibility Search & Display Options

Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author Simoneau, A.; Aubé, M.; Bertolo, A. url  doi
openurl 
  Title Multispectral analysis of the night sky brightness and its origin for the Asiago Observatory, Italy Type Journal Article
  Year 2020 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal MNRAS  
  Volume 491 Issue 3 Pages 4398-4405  
  Keywords Skyglow; light pollution; numerical methods; Site testing; Italy; Observatories  
  Abstract Night protection has been a major concern for astronomers since the electrification of cities and is beginning to be recognized as a major environmental problem. In recent years, regulations have been put in place through the establishment of Dark Sky Reserves that impose stringent constraints on lighting practices for cities in protected areas. Astronomers from the Asiago Observatory, located in the Veneto region of Italy, would like to create an area of this nature around their facilities to improve and protect the quality of their astronomical observations. This study assesses the current state of the sky in the region through numerical modelling using the latest improvements to the ILLUMINA model and aims to identify the main contributing sources of artificial light. The explicit calculation of the contribution of private residential lighting helps to discern the origin of the light. We also present a new approach for extracting an estimate of the distribution of lamp technology in a region from images taken from the International Space Station.  
  Address Bishop’s University, 2600 rue College, Sherbrooke, Québec J1M 1Z7, Canada; alsimoneau(at)gmail.com  
  Corporate Author Thesis  
  Publisher (down) 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 0035-8711 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 2790  
Permanent link to this record
 

 
Author Bará, S.; Aubé, M.; Barentine, J.; Zamorano, J. url  doi
openurl 
  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 (down) 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 Kocifaj, M.; Bará, S. url  doi
openurl 
  Title Aerosol characterization using satellite remote sensing of light pollution sources at night Type Journal Article
  Year 2020 Publication Monthly Notices of the Royal Astronomical Society: Letters Abbreviated Journal MNRAS  
  Volume 495 Issue 1 Pages L76-L80  
  Keywords Skyglow; Radiative transfer; Light scattering; Aerosols  
  Abstract A demanding challenge in atmospheric research is the night-time characterization of aerosols using passive techniques, that is, by extracting information from scattered light that has not been emitted by the observer. Satellite observations of artificial night-time lights have been used to retrieve some basic integral parameters, like the aerosol optical depth. However, a thorough analysis of the scattering processes allows one to obtain substantially more detailed information on aerosol properties. In this letter, we demonstrate a practicable approach for determining the aerosol particle size number distribution function in the air column, based on the measurement of the angular radiance distribution of the scattered light emitted by night- time lights of cities and towns, recorded from low Earth orbit. The method is self-calibrating and does not require the knowledge of the absolute city emissions. The input radiance data are readily available from several spaceborne platforms, like the VIIRS-DNB radiometer onboard the Suomi-NPP satellite.  
  Address Faculty of Mathematics, Physics, and Informatics, Comenius University, Mlynska Dolina, 842 48 Bratislava, Slovakia; Miroslav.Kocifaj(at)savba.sk  
  Corporate Author Thesis  
  Publisher (down) OUP Place of Publication Editor  
  Language English Summary Language English Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1745-3925 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 2910  
Permanent link to this record
 

 
Author Bará, S.; Nievas, M.; Sanchez de Miguel, A.; Zamorano, J. url  openurl
  Title Zernike analysis of all-sky night brightness maps Type Journal Article
  Year 2014 Publication Applied Optics Abbreviated Journal Appl Opt  
  Volume 53 Issue 12 Pages 2677-2686  
  Keywords modeling; light at night; light pollution; all-sky; Zernike polynomials; image decomposition; sky brightness  
  Abstract All-sky night brightness maps (calibrated images of the night sky with hemispherical field-of-view (FOV) taken at standard photometric bands) provide useful data to assess the light pollution levels at any ground site. We show that these maps can be efficiently described and analyzed using Zernike circle polynomials. The relevant image information can be compressed into a low-dimensional coefficients vector, giving an analytical expression for the sky brightness and alleviating the effects of noise. Moreover, the Zernike expansions allow us to quantify in a straightforward way the average and zenithal sky brightness and its variation across the FOV, providing a convenient framework to study the time course of these magnitudes. We apply this framework to analyze the results of a one-year campaign of night sky brightness measurements made at the UCM observatory in Madrid.  
  Address Área de Óptica, Dept. de Física Aplicada, Fac. de Física, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Galicia, Spain  
  Corporate Author Thesis  
  Publisher (down) Optical Society of America Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-6935 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:24787595 Approved no  
  Call Number IDA @ john @ Serial 318  
Permanent link to this record
 

 
Author Bará, S.; Tilve, V.; Nievas, M.; Sanchez de Miguel, A.; Zamorano, J. url  doi
openurl 
  Title Zernike power spectra of clear and cloudy light-polluted urban night skies Type Journal Article
  Year 2015 Publication Applied Optics Abbreviated Journal Appl. Opt.  
  Volume 54 Issue 13 Pages 4120-4129  
  Keywords Skyglow; artificial ligh at night; light pollution; Zernike; power spectrum; atmospheric optics; imaging systems; image analysis  
  Abstract The Zernike power spectra of the all-sky night brightness distributions of clear and cloudy nights are computed using a modal projection approach. The results obtained in the B, V and R Johnson-Cousins' photometric bands during a one-year campaign of observations at a light-polluted urban site show that these spectra can be described by simple power laws with exponents close to -3 for clear nights and -2 for cloudy ones. The second-moment matrices of the Zernike coefficients show relevant correlations between modes. The multiplicative role of the cloud cover, that contributes to a significant increase of the brightness of the urban night sky in comparison with the values obtained in clear nights, is described in the Zernike space.  
  Address Area de Optica, Dept. Fisica Aplicada. Facultade de Fisica / Facultade de Optica e Optometría Universidade de Santiago de Compostela Campus Sur, E-15782 Santiago de Compostela, Galicia, Spain; salva.bara@usc.es  
  Corporate Author Thesis  
  Publisher (down) Optical Society of America 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 1156  
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print

Save Citations:
Export Records: