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Wave Field Impedance

NSSDCA ID: 1977-029A-11

Mission Name: ESA-GEOS 1
Principal Investigator:Dr. Christian Beghin


This investigation (part of ESA Exp. S-300) made use of one set of electric mesh spheres mounted on the end of the axial booms (part of 77-029A-10, Ungstrup) and the two vitreous carbon spheres mounted on the end of the 20-m radial booms (77-029A-07, Pedersen). The mesh spheres were used as transmitting elements for frequencies from 0.2 to 76 kHz. The self-impedance of these spheres and the mutual impedance between the mesh and long-boom carbon spheres were measured. Strong resonances at the hybrid resonance frequencies and anti-resonances at the gyro frequencies were used to determine the density of the surrounding plasma. Frequencies up to 450 Hz could be telemetered directly, and sweep-frequency analyzers and a digital correlation could be employed to obtain auto-correlation and/or cross-correlation up to 77 kHz with selectable bandwidths of 2.5, 5.0, or 10.0 kHz.

Alternate Names

  • ESA-GEOS1/WaveFieldImpedance

Funding Agency

  • European Space Agency (International)


  • Space Physics: Magnetospheric Studies

Additional Information

Questions and comments about this experiment can be directed to: Coordinated Request and User Support Office



NameRoleOriginal AffiliationE-mail
Dr. Pierrette DecreauOther InvestigatorCNRS, Centre Spectrometric Nucleaire et
Dr. Christian BeghinPrincipal InvestigatorCNRS, Centre Spectrometric Nucleaire et
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