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Magnetic Fields Measurement (MGF)

NSSDCA ID: 1992-044A-06

Mission Name: Geotail
Principal Investigator:Dr. Susumu K. Kokubun


The objective of this experiment is to measure the magnetic field variation of the magnetotail in the frequency below 50 Hz. The MGF experiment consists of dual three-axis fluxgate magnetometers and a three-axis search coil magnetometer. Triad fluxgate sensors, which utilize a ring core geometry, are installed at the end and middle of a 6 m deployable mast. Three search coils are mounted approximately one-half of the way out on another 6 m boom together with search coils for the VLF wave in the PWI system. The fluxgate magnetometers are of standard design and consist of an amplifier, filter, phase sensitive detector, integrator, and a voltage-current convertor. The fluxgate magnetometers operate in seven dynamic ranges to cover various regions of the Earth's magnetosphere and the solar wind: +/-16 nT, +/-64 nT, +/-256 nT, +/-1024 nT, +/-4096 nT, +/-16384 nT, and +/-65536 nT, and supply 16 vectors/sec. The search coil magnetometer system consists of three sensors, preamplifier, amplifier, filter, multiplexer, and an A/D converter. The search coil magnetometers operate in a frequency range of 0.5 kHz to 1 kHz, and supply 128 vectors/sec. The fluxgate magnetometer operates in both real time and record modes, while the search coil data are used only in real time mode.

Alternate Names

  • Geotail/MGF
  • MGF

Facts in Brief

Mass: 6.1 kg
Power (avg): 3 W
Bit rate (avg): 3.584 kbps

Funding Agencies

  • Institute of Space and Aeronautical Science, U of Tokyo (Japan)
  • National Aeronautics and Space Administration (United States)


  • Space Physics: Magnetospheric Studies

Additional Information

Questions and comments about this experiment can be directed to: Dr. Ramona L. Kessel



NameRoleOriginal AffiliationE-mail
Dr. Atsuhiro NishidaCo-InvestigatorInstitute of Space and Aeronautical
Dr. Ronald P. LeppingCo-InvestigatorNASA Goddard Space Flight
Dr. Takesi IijimaCo-InvestigatorUniversity of
Dr. Tohru SakuraiCo-InvestigatorTokai University
Dr. Mario H. AcunaCo-InvestigatorNASA Goddard Space Flight Center
Dr. Kanji HayashiCo-InvestigatorUniversity of
Dr. Hiroshi FukunishiCo-InvestigatorUniversity of
Mr. F. TohyamaCo-InvestigatorTokai University
Dr. Toyo KameiCo-InvestigatorKyoto University
Dr. Kiyohumi YumotoCo-InvestigatorNagoya
Dr. Kazuo ShiokawaCo-InvestigatorNagoya University
Dr. Yutaka TonegawaCo-InvestigatorTokai University
Dr. Tatsundo YamamotoCo-InvestigatorUniversity of Tokyo
Dr. Susumu K. KokubunPrincipal InvestigatorUniversity of

Selected References

  • Kokubun, S., et al., Magnetic field measurement (MGF), in Geotail Prelaunch Report, SES-TD-92-007SY, Institute of Space and Astronautical Science, SES Data Center, pp. 58-70, Apr. 1992.
  • Nishida, A., et al., Geotail mission to explore earth's magnetotail, EOS, 73, No. 40, 425-429, doi:10.1029/91EO00314, Oct. 1992.
  • Kokubun, S., et al., The GEOTAIL Magnetic Field Experiment, J. Geomag. Geoelectr., 46, No. 1, 7-21, doi:10.5636/jgg.46.7, 1994.
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