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Triaxial Search-Coil Magnetometer

NSSDCA ID: 1966-049A-12

Mission Name: OGO 3
Principal Investigator:Dr. Edward J. Smith


In this experiment, magnetic field variations were measured triaxially from 0.01 to 800 Hz by a boom-mounted search coil magnetometer with high-permeability core. Two digitally sampled and one analog broadband channel mapped the vector wave data. The two digital channels covered frequencies from 0.01 to 0.8 Hz or 0.01 to 75 Hz, depending on telemetry rate. The analog channel, transmitted via the FM special-purpose telemetry, covered from 1 to 1000 Hz. Also included was a five-channel spectrum analyzer with center frequencies at 10, 32, 100, 320, and 800 Hz. These channels overlapped at the -12 dB points. The time required for a triaxial spectrum analysis varied with telemetry rate from 147 s to 18.4 s to 2.3 s for the 1, 8, and 64 kbs rates, respectively. The instrument performed throughout the operational life of the spacecraft, but the usefulness of the three broadband channels was greatly reduced by interference from the digital spectrum analyzer channels. More details regarding experiment design may be found in Frandsen, A. M. A., et al., "OGO search coil magnetometer experiments," IEEE Trans. on Geosci. Electron., v. GE-7, n. 2, pp. 61-74, April 1969.

Alternate Names

  • OGO3/TriaxialSearch-CoilMagnetometer


  • Space Physics: Magnetospheric Studies
  • Space Physics: Heliospheric Studies

Additional Information

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



NameRoleOriginal AffiliationE-mail
Prof. Robert E. HolzerOther InvestigatorUniversity of California, Los Angeles
Dr. Edward J. SmithPrincipal InvestigatorNASA Jet Propulsion

Selected References

  • Frandsen, A. M. A., et al., OGO search coil magnetometer experiments, IEEE Trans. Geosci. Electron., GE-7, 61-74, doi:10.1109/TGE.1969.271324, Apr. 1969.
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