  We present a method to map the artificial sky brightness across large
territories in astronomical photometric bands with a resolution of
approximately 1 km. This is useful to quantify the situation of night sky
pollution, to recognize potential astronomical sites and to allow future
monitoring of trends. The artificial sky brightness present in the chosen
direction at a given position on the Earth's surface is obtained by the
integration of the contributions produced by every surface area in the
surrounding. Each contribution is computed based on detailed models for the
propagation in the atmosphere of the upward light flux emitted by the area. The
light flux is measured with top of atmosphere radiometric observations made by
the Defense Meteorological Satellite Program (DMSP) Operational Linescan
System.
  We applied the described method to Europe obtaining the maps of artificial
sky brightness in V and B bands.
