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5.12 s Vector Magnetic Field Data


Availability: At NSSDC, Ready for Offline Distribution (or Staging if Digital)

Time span: 1967-07-19 to 1972-02-23


This data set consists of experimenter-supplied, 5.12-s-averaged magnetic field vector data on binary magnetic tapes written on an IBM 360 computer. Each physical record contains four logical records of 1092 bytes each. Each logical record contains data taken during one 81.92-s telemetry sequence. Included in each logical record are time (with January 1=day 0) and 16 vector magnetic field measurements with Cartesian components given in four coordinate systems: (1) a payload system corotating with the spacecraft; (2) a system with its Z axis along the spacecraft spin axis and its X axis in the plane defined by the spin axis and the satellite-sun line; (3) GSE coordinates; and, (4) GSM coordinates. For the latter three coordinate systems, sequence averages and rms deviations are given for the components. In addition, 16 field magnitudes and the sequence-averaged magnitude and its rms deviation are given.

The latitude and azimuth angles of the sequence-averaged field vector are given in the payload and GSE coordinate systems. The data have not been corrected for lunar shadow effects. As such, field direction information is unreliable during lunar shadow periods. Supporting information found in each logical record includes time for the 16 field measurements; spin period; direction; and spacecraft position in GSE, selenocentric solar ecliptic, and GSM coordinates.

For the first three years or so, data coverage is nearly 100% complete, but for the last year or so a significant number of data gaps appear. There is some modulation in the late-time-period 5.12 s data, probably due to the data-gap-associated inability of the filtering program to remove all spin modulation. The 81.92-s-averaged data were expected to be more reliable for this late time period. A separate set of tapes with just the 81.92-s-averaged magnetic field data is also available (SPHE-00615).

Alternate Names

  • 5.12 s Vector Mag Field Data


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


  • 67-070A-04A

Additional Information



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



NameRoleOriginal AffiliationE-mail
Dr. Norman F. NessData ProviderNASA Goddard Space Flight Center
Dr. Norman F. NessGeneral ContactNASA Goddard Space Flight Center

Selected References

  • Scearce, C. S., et al., GSFC magnetic field experiment, Explorers 33 and 35, NASA-GSFC, X-616-69-53, Greenbelt, MD, Feb. 1969.
  • Behannon, K. W., et al., AIMP D and E magnetic field analysis, NASA-GSFC, X-616-68-382, Greenbelt, MD, Oct. 1968.
  • Mish, W. H., and H. E. Haney, AIMP information processing system software, NASA-GSFC, X-612-65-501, Greenbelt, MD, May 1966.
  • King, J. H., IMP series report/bibliography, NASA-GSFC, NSSDC 71-21, Greenbelt, Md., Dec. 1971.
  • Fairfield, D. H., et al., Trajectories of Explorers 33, 35, 41, 43, and 47 - May 1969-December 1972, NASA-GSFC, TM-X-70481, X-692-73-291, Greenbelt, MD, Oct. 1973.
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