1. Department of Astronomy, ELTE Eötvös Loránd University, H-1117 Budapest, Pázmány sétány 1, Hungary
2. Environmental Optics Laboratory, Department of Biological Physics, ELTE Eötvös Loránd University, H-1117 Budapest, Pázmány sétány 1, Hungary
3. Estrato Research and Development Ltd., H-1124 Németvölgyi út 91/c, Budapest, Hungary