1. Physics Department; University of Wuppertal; Wuppertal Germany
2. Department of Physics and Astronomy; Western Kentucky University; Bowling Green Kentucky USA
3. Institute of Space and Atmospheric Studies; University of Saskatchewan; Saskatoon Canada
4. Laboratory for Hydrospheric Processes, Observational Science Branch; NASA/GSFC Wallops Flight Facility; Wallops Island Virginia USA
5. Leibniz-Institut für Atmosphärenphysik; Kühlungsborn Germany
6. Department of Physics and Mathematical Physics; University of Adelaide; Adelaide Australia