The Galician Night Sky Brightness Monitoring Network
Salvador Bará,1* Víctor Tilve, 2 Santiago Salsón,3 Miguel Rúa,3 and Vicente Pérez-Muñuzuri3,4
1Optics
Area, Dept. of Applied Physics, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Galicia, Spain.
2Astronomical Observatory "R.M. Aller", Dept. of Applied Mathematics, Universidade de Santiago de Compostela, 15782 Santiago de
Compostela, Galicia, Spain.
3MeteoGalicia, Consellería de Medio Ambiente, Territorio e Infraestruturas, Rúa Roma nº 6, 15707 Santiago de Compostela, Galicia, Spain
4Dept. of Condensed Matter Physics, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Galicia, Spain.
(*) salva.bara@usc.es
Abstract
The Galician Night Sky Brightness Monitoring Network is a
public system of SQM-LR detectors installed in several weather
stations of MeteoGalicia, the Galician official meteorological
agency, in cooperation with the University of Santiago de
Compostela. A set of 13 detectors continuosly acquire brightness
data at sites located within heavily light polluted urban areas as well
as in remote places at the Eastern Mountains and National Parks of
Galicia. Ten-minute resolution data are available in real time for
public dissemination and download from the MeteoGalicia website.
One-minute resolution datasets are freely available upon request. In
this communication we describe this network and the science
results obtained after its first operational year.
A Public Information Service on Light Pollution
provided by USC and MeteoGalicia, the official
Galician Meteorological Agency
Open access and public dissemination of data
The measurements of all stations can be accessed in real time at
the MeteoGalicia website.
Live information for each station
includes the last 60 h ten-minute
data plots, and the maximum
and
average
night
sky
brightness for the last four
nights. Monthly plots display the
evolution of the maximum and
average brightness. The pages
also contains useful links to
related
sites,
educational
materials, and the option of
direct data download.
Five stations are located at urban areas along the Atlantic shoreline; six at
dark locations in the Eastern Mountains, and the remaining two in the
Galician Atlantic Islands Maritime-Terrestrial National Park
An instrumental service for
long-term site monitoring
Data from the stations of Cabeza de
Manzaneda, period April 14 to Dec 31,
2014 (top), and Santiago de Compostela,
period Jan 1 to Dec 31, 2014 (bottom).
Left: Density plots; Center: Histograms of
recorded values; Right: Nightly traces. The
different behaviour of the night sky
brightness at a remote station and at one
within a 100.000 inhabitants town can be
easily assessed. Bimodal histograms
reveal the light pollution levels prevalent at
each site, the relative frequency of cloud
coverage, and the cloud amplification
factors. Nightly traces show that in urban
settings the periodic modulation of the
night sky brightness due to the Moon cycle
is almost lost.
This work was partially funded by the Galician Government, Programa de
Consolidación e Estruturación de Unidades de Investigación Competitivas,
grant CN2012/156, and was developed within the framework of the
Spanish Network for Light Pollution Studies (Ministerio de Economía y
Competitividad, Acción Complementaria AYA2011-15808-E) whose
support is also acknowledged.