  Evidence of the negative impact of light pollution on ecosystems is
increasing every year. Its monitoring and study requires the identification,
characterisation and control of the emitting sources. This is the case of urban
centres with outdoor lighting that spills light outside the place it is
intended to illuminate. The quantity and nature of the pollutant (artificial
light at night) depends on the lamps used and how they are positioned. This is
important because a greater proportion of blue light means a greater scattering
effect. In this study, we analysed the emissions of 100 urban centres in the
north of Granada province (Spain), using International Space Station (ISS)
images from 2012 and 2021, in order to compare the results with public lighting
inventories and verify the validity of these data for characterising night-time
lighting emissions. Using inference and cluster analysis techniques, we
confirmed an overall increase in emissions and a shift in their colour towards
blue, consistent with the results of the lighting inventory analysis. We
concluded that it is possible to use ISS imagery to characterise artificial
light emissions and the lighting that causes them, none the less there are a
number of inherent problems with the data and the way it was collected that
require the results to be interpreted with caution.
