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Aubé, M. (2007). Light pollution modeling and detection in a heterogeneous environment. Proceedings of Starlight 2007 conference. La Palma, Spain., .
Abstract: Few attempts have been made to measure aerosol optical depth (AOD) behaviour
during the night. One such method uses spectrally calibrated stars as reference targets
but the available number of stars is limited. This is especially true for urban sites where
artificial lighting hide most of these stars. In our research we attempt to provide an
alternate method one which exploits the artificial sky glow generated by light pollution.
To achieve that goal, we designed a new methodology which links a 3D light
pollution model with in situ light pollution spectral measurements obtained with our
detector called Spectrometer for aerosol night detection (SAND). The basic idea was to
adjust an AOD value into the model in order to fit the measured artificial sky brightness.
This method requires an accurate model that includes spatial heterogeneity in lighting
angular geometry, in lighting spectral dependence, in ground spectral reflectance and
in topography along with a detailed definition of the vertical atmospheric profile. This
model, named ILLUMINA, computes 1st and 2nd order molecular and aerosol scattering
as well as aerosol absorption. A correction for sub grid obstacles is also included.
These model features represent major improvements to previous light pollution models.
Therefore, new possibilities for light pollution studies will arise, many of which are of
particular interest to the astronomical community. In this paper we will present model
and detector features and some of the first results derived from ILLUMINA model. We
will also present our web based spatio-temporal Sky spectral luminance measurements