1. Department of Atmospheric, Oceanic, and Space Sciences; University of Michigan; Ann Arbor Michigan USA
2. Center for Geospace Studies; SRI International; Menlo Park California USA
3. Haystack Observatory; Massachusetts Institute of Technology; Westford Massachusetts USA
4. Institute for Scientific Research; Boston College; Chestnut Hill Massachusetts USA
5. Department of Atmospheric and Oceanic Sciences, UCLA; Los Angeles California USA
6. Department of Physics and Astronomy; University of Calgary; Calgary Alberta Canada