1. Electrical Engineering Faculty, Bialystok University of Technology, Bialystok, Poland
2. Departamento de Física Aplicada, Universidade de Santiago de Compostela, Santiago de Compostela, Galicia
3. Physics Department, Cégep de Sherbrooke, Sherbrooke, Quebec, Canada
4. International Dark-Sky Association, Tucson, Arizona, USA
5. Consortium for Dark Sky Studies, University of Utah, Salt Lake City, Utah, USA
6. Department Física de la Tierra y Astrofísica, Instituto de Física de Partículas y del Cosmos (IPARCOS), Universidad Complutense de Madrid, Madrid, Spain