1. Department of Atmospheric and Oceanic Sciences University of California, Los Angeles Los Angeles CA USA
2. Department of Atmospheric and Oceanic Sciences and Department of Earth, Planetary, and Space Sciences University of California, Los Angeles Los Angeles CA USA
3. Center for Space Physics and Department of Electrical and Computer Engineering Boston University Boston MA USA
4. Center for Geospace Studies SRI International Menlo Park CA USA
5. Geophysical Institute University of Alaska Fairbanks Fairbanks AK USA
6. Department of Electrical and Computer Engineering Center for Space Science and Engineering Research Blacksburg VA USA
7. Department of Physics and Astronomy University of Calgary Calgary AL Canada