1. Department of Physics; Catholic University of America; Washington DC USA
2. NASA Goddard Space Flight Center; Greenbelt MD USA
3. Department of Astronomy; University of Maryland; College Park MD USA
4. Geophysical Institute; University of Alaska Fairbanks; Fairbanks AK USA
5. Department of Physics and Astronomy; University of Texas at San Antonio; San Antonio TX USA
6. Space Science and Engineering; Southwest Research Institute; San Antonio TX USA