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Author Rabaza, O.; Galadi-Enriquez, D.; Estrella, A.E.; Dols, F.A. url  doi
openurl 
  Title All-sky brightness monitoring of light pollution with astronomical methods Type Journal Article
  Year (down) 2010 Publication Journal of Environmental Management Abbreviated Journal J Environ Manage  
  Volume 91 Issue 6 Pages 1278-1287  
  Keywords *Astronomy; Calibration; *Environmental Pollutants; *Light  
  Abstract This paper describes a mobile prototype and a protocol to measure light pollution based on astronomical methods. The prototype takes three all-sky images using BVR filters of the Johnson-Cousins astronomical photometric system. The stars are then identified in the images of the Hipparcos and General Catalogue of Photometric Data II astronomical catalogues, and are used as calibration sources. This method permits the measurement of night-sky brightness and facilitates an estimate of which fraction is due to the light up-scattered in the atmosphere by a wide variety of man-made sources. This is achieved by our software, which compares the sky background flux to that of many stars of known brightness. The reduced weight and dimensions of the prototype allow the user to make measurements from virtually any location. This prototype is capable of measuring the sky distribution of light pollution, and also provides an accurate estimate of the background flux at each photometric band.  
  Address Department of Civil Engineering, University of Granada, Severo Ochoa Str. s/n, 18071 Granada, Spain. ovidio@ugr.es  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0301-4797 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:20199844 Approved no  
  Call Number IDA @ john @ Serial 192  
Permanent link to this record
 

 
Author Muheim, R.; Phillips, J.B.; Akesson, S. url  doi
openurl 
  Title Polarized light cues underlie compass calibration in migratory songbirds Type Journal Article
  Year (down) 2006 Publication Science (New York, N.Y.) Abbreviated Journal Science  
  Volume 313 Issue 5788 Pages 837-839  
  Keywords Alaska; *Animal Migration; Animals; Calibration; Cues; *Flight, Animal; Geography; *Light; Magnetics; *Orientation; Seasons; Sparrows/*physiology; Sunlight  
  Abstract Migratory songbirds use the geomagnetic field, stars, the Sun, and polarized light patterns to determine their migratory direction. To prevent navigational errors, it is necessary to calibrate all of these compass systems to a common reference. We show that migratory Savannah sparrows use polarized light cues from the region of sky near the horizon to recalibrate the magnetic compass at both sunrise and sunset. We suggest that skylight polarization patterns are used to derive an absolute (i.e., geographic) directional system that provides the primary calibration reference for all of the compasses of migratory songbirds.  
  Address Department of Animal Ecology, Lund University, Ecology Building, SE-223 62 Lund, Sweden. rmuheim@vt.edu  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0036-8075 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:16902138 Approved no  
  Call Number IDA @ john @ Serial 243  
Permanent link to this record
 

 
Author Cinzano, P. url  openurl
  Title Night Sky Photometry with Sky Quality Meter Type Journal Article
  Year (down) 2005 Publication Technical Report 9, ISTIL. V1.4. Abbreviated Journal  
  Volume Issue Pages  
  Keywords Instrumentation; light pollution; night sky brightness; photometry; instruments; calibration  
  Abstract Sky Quality Meter, a low cost and pocket size night sky brightness photometer, opens to the general public the possibility to quantify the quality of the night sky. Expecting a large diffusion of measurements taken with this instrument, I tested and characterized it. I analyzed with synthetic photometry and laboratory measurements the relationship between the SQM photometrical system and the main systems used in light pollution studies. I evaluated the conversion factors to Johnson’s B and V bands, CIE photopic and CIE scotopic responses for typical spectra and the spectral mismatch correction factors when specific filters are added.  
  Address Dipartimento di Astronomia, Vicolo dell’Osservatorio 2, I-35100 Padova, Italy; cinzano(at)lplab.it  
  Corporate Author Thesis  
  Publisher ISTIL 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 LoNNe @ christopher.kyba @ Serial 473  
Permanent link to this record
 

 
Author Cochran, W.W.; Mouritsen, H.; Wikelski, M. url  doi
openurl 
  Title Migrating songbirds recalibrate their magnetic compass daily from twilight cues Type Journal Article
  Year (down) 2004 Publication Science (New York, N.Y.) Abbreviated Journal Science  
  Volume 304 Issue 5669 Pages 405-408  
  Keywords *Animal Migration; Animals; Biological Clocks; Calibration; Cues; *Flight, Animal; Geography; *Magnetics; *Orientation; *Solar System; Songbirds/*physiology  
  Abstract Night migratory songbirds can use stars, sun, geomagnetic field, and polarized light for orientation when tested in captivity. We studied the interaction of magnetic, stellar, and twilight orientation cues in free-flying songbirds. We exposed Catharus thrushes to eastward-turned magnetic fields during the twilight period before takeoff and then followed them for up to 1100 kilometers. Instead of heading north, experimental birds flew westward. On subsequent nights, the same individuals migrated northward again. We suggest that birds orient with a magnetic compass calibrated daily from twilight cues. This could explain how birds cross the magnetic equator and deal with declination.  
  Address Illinois Natural History Survey, 607 East Peabody Drive, Champaign, IL61820, USA. Sparrow@springnet1.com  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0036-8075 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:15087541 Approved no  
  Call Number IDA @ john @ Serial 57  
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