The reliability of satellite-based lighttrends for dark sky areas in Austria

Le résumé fourni par la source

Globally, light pollution is a phenomenon rising in its appearance and threatening human health and natural habitats for flora and fauna. Consequently, there is a great interest in interdisciplinary communities to keep an eye on its occurrence and development. One possibility to obtain meaningful data are satellite-based observations, coming mainly from the Visible Infrared Imaging Radiometer Suite (VIIRS) capturing top-of-the-atmosphere radiance levels originating from Earth’s surface. Tools designed to easily inspect monthly averaged data of this instrument are web applications. In this work, we focus on dark sky areas in Austria, namely 47 nature parks, and investigate collected data from such application and their reliability in making statements about the development of artificial light at night on the ground. Including atmospheric variations and other limitations, our results lead to a detection limit in radiance change by a minimum of ±10%. Below this value, detected changes in surface brightness must not be traced back to changes of ground-based artificial light according to a specified statistical significance of three sigma. In total, 38 of 47 nature parks are examinable, showing an increase in radiance by ∼42 percent over ten years in average, more than double compared to the entire national territory. As a conclusion, satellite data as analysed must be available for large periods, in order to decrease detection thresholds and make accurate statements about the development of light pollution. However, for detailed analytical research, it is highly recommended that especially dark areas globally establish ground-based light monitoring networks in their areas.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.