1. The Johns Hopkins University Applied Physics Laboratory Laurel MD USA
2. Geophysical InstituteUniversity of Alaska Fairbanks Fairbanks AK USA
3. Office of Space Research and Technology Academy of Athens Athens Greece
4. Southwest Research Institute San Antonio TX USA
5. Department of Physics and AstronomyUniversity of Texas at San Antonio San Antonio TX USA
6. Southwest Research Institute Boulder CO USA
7. National Aeronautics and Space Administration Ames Research Center Moffett Field CA USA
8. Department of Physics and Astronomy George Mason University Fairfax VA USA