The Johns Hopkins University. Applied Physics Laboratory, 11100 Johns Hopkins Rd., Laurel, MD 20723, USA
The Johns Hopkins University. Applied Physics Laboratory, 11100 Johns Hopkins Rd., Laurel, MD 20723, USA
Research and Scientific Support Department. European Space Agency, Keplerlaan, 1, Noordwijk, NL-2200 AG, Netherlands
Bell Laboratories. Lucent Technologies, 600 Mountain Av., Murray Hill, NJ 07974, USA; Center for Solar-Terrestrial Research. New Jersey Institute of Technology, University Heights, Newark, NJ 07102, USA