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THE ARTIFICIAL NIGHT SKY BRIGHTNESS AT OCCULTATION OBSVERING STATIONS IN EUROPE

Merging the collected data for the station maps with the data from the "World Atlas of Artificial Sky Brightness", I have made the following maps. These maps should give observers an insight about the artificial sky brightness at thier locations and at possible expeditions sites.

Many thanks to Pierantonio Cinzano (ISTIL Light Pollution Science and Technology Institute of Thiene, Italy, www.istil.it ) for his kind permission to use the "World Atlas of Artificial Sky Brightness" as a background for these special station maps.

Credit for all artificial sky brightness data:
P. Cinzano, F. Falchi (University of Padova), C. D. Elvidge (NOAA National Geophysical Data Center, Boulder). Copyright Royal Astronomical Society. Reproduced from the Monthly Notices of the RAS by permission of Blackwell Science.


How to read these maps? A very short summary from the web page of "World Atlas of Artificial Sky Brightness".
Please have a look at   www.lightpollution.it/dmsp/  for a full description of how this data was obtained and how to read it. There are additional interesting maps at these web pages.

- The colour code allows to compare the light pollution at zenith at sea level. However you do not see a big difference accounting for altitude.

- Colours correspond to ratios between the artifical sky brightness and the natural sky brightness of:
    <0.11 (black), 0.11-0.33 (blue), 0.33-1 (green), 1-3 (yellow), 3-9 (orange), >9 (red)

- These maps are intended to show the levels of pollution in the atmosphere rather than the stellar visibility, but the colour code can give an estimate:
   Red: approximately one hundredth of stars, or few more, is visible over 30 degrees of elevation
   Orange: the milky way is invisible or quite difficult to see by an average observer in normal clear nights
   Yellow: artificial sky brightness equal to the natural so that the total sky brightness is doubled
   Blue: artificial sky brightness over 10% than the natural brightness which is the definition of "light polluted sky"

- The maps show the artificial sky brightness at the zenith in clear nights in V band.

Finally I want to thank Odilon Ferreira Junior from Brazil for his fine software "GPS TrackMaker" ( www.gpstm.com ), which I used for creating these maps and all the other station maps before.


Oliver Klös

IOTA-ES



THE MAPS:

Beligum, The Netherlands, Germany bng
Czech Republic, Slovakia cs
France france
Greece greece
Hungary, Romania hr
Ireland, U.K. iu
Italy italy
Norway, Denmark, Finland ndf
Poland poland
Portugal, Spain ps
Switzerland, Austria sa



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