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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 |
|
Czech Republic, Slovakia |
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France |
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Greece |
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Hungary, Romania |
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Ireland, U.K. |
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Italy |
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Norway, Denmark, Finland |
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Poland |
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Portugal, Spain |
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Switzerland, Austria |
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