1. Institute of Radio Frequency Engineering and Electronics, Karlsruhe Institute of Technology, Karlsruhe, Germany
2. Fraunhofer Institute for High Frequency Physics and Radar Techniques FHR, Wachtberg, Germany
3. Ruhr University Bochum, Bochum, Germany
4. Centre d’Études de la Neige, Saint-Martin-d’Hères, France
5. Laboratoire d’Océanographie et du Climat, Paris, France
6. Laboratoire Atmosphères, Milieux, Observations Spatiales, Paris, France