1. Space Science Division U.S. Naval Research Laboratory Washington DC USA
2. Department of Applied Sciences, College of Arts and Sciences Embry‐Riddle Aeronautical University Daytona Beach FL USA
3. NASA Langley Research Center Hampton VA USA
4. Department of Physics and Astronomy University of Western Ontario London Ontario Canada
5. Institute of Applied Physics, Microwave Physics University of Bern Bern Switzerland
6. Sodankylä Geophysical Observatory University of Oulu Sodankylä Finland
7. Department of Physics and Astronomy University of Leicester Leicester UK
8. Leipzig Institute for Meteorology Universität Leipzig Leipzig Germany