1. The Johns Hopkins University Applied Physics Laboratory Laurel MD USA
2. Naval Research Laboratory Washington DC USA
3. Department of Space Science Aerospace Corporation Chantilly VA USA
4. Department of Physics and Astronomy Dartmouth College Hanover NH USA
5. Department of Physical and Chemical Sciences University of L’Aquila L’Aquila Italy
6. Consorzio Area di Ricerca in Astrogeofisica L’Aquila Italy
7. Institute for the Study of Earth, Oceans, and Space, University of New Hampshire Durham NH USA