1. Center for Space and Atmospheric Research; Embry-Riddle Aeronautical University; Daytona Beach Florida USA
2. Department of Electronics and Nanoengineering, School of Electrical Engineering; Aalto University; Espoo Finland
3. Geophysical Institute; University of Alaska Fairbanks; Fairbanks Alaska USA
4. College of Engineering, Mathematics and Physical Sciences; University of Exeter; Exeter UK