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DC and low frequency electric fields, double-probe, 0.19-1900 Hz

NSSDCA ID: 1977-102A-11

Mission Name: ISEE 1
Principal Investigator:Dr. James P. Heppner


This experiment was intended to study quasi-static electric fields and low-frequency plasma waves in the plasmasphere, magnetosphere, magnetosheath, and solar wind. The double-probe floating-potential technique was applied using long-wire antenna probes with an effective electric field baseline of 179 m. The dc differential voltage was measured 8 or 32 times per s, depending on bit rate. In addition, the dc field was measured at selected azimuthal angles relative to the sun and the magnetic field, and the peak value of delta V and its azimuthal angles were measured. Low-frequency waves were measured in eight frequency bands as follows: 0.19 to 0.6, 0.6 to 1.9, 1.9 to 6, 6 to 19, 19 to 60, 60 to 190, 190 to 600, and 600 to 1900 Hz. The dc-mode measurements had a two-step, variable-gain amplifier controlled from the ground. The resolution in the highest gain state was 0.5E-6 V/m. The ac measurement electronics consisted of two amplifier sections. One amplifier was used for low-frequency channels, and one for high-frequency channels. Gain lines for each amplifier were independently controllable from the ground. In the highest-gain mode, each analyzer channel had a sensitivity of 0.04E-6 V/m (rms). The experiment could be run in either a sun-sensor synchronized or a free state as controlled from the ground. In addition, the ac portion could be run in an averaging mode, or an alternating averaging and peak-amplitude-detection mode keyed to the telemetry readout sequence.

Alternate Names

  • ISEE1/DCandlowfrequencyelectricfields,double-probe,0_19-1900Hz

Facts in Brief

Mass: 8.1 kg
Power (avg): 3.7 W

Funding Agency

  • NASA-Office of Space Science (United States)


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

Additional Information

Questions and comments about this experiment can be directed to: Dr. H. Kent Hills



NameRoleOriginal AffiliationE-mail
Dr. Thomas L. AggsonOther InvestigatorNASA Goddard Space Flight Center
Prof. Donald A. GurnettOther InvestigatorUniversity of Iowa
Dr. Nelson C. MaynardOther InvestigatorPhillips Laboratory (nee USAF Geophysics Lab, nee Cambridge Labs)
Dr. David P. CauffmanOther InvestigatorLockheed Palo
Dr. James P. HeppnerPrincipal InvestigatorNASA Goddard Space Flight Center

Selected References

  • Heppner, J. P., et al., Instrumentation for DC and low-frequency electric-field measurements on ISEE-A, IEEE Trans. Geosci. Electron., GE-16, No. 3, 253-257, doi:10.1109/TGE.1978.294557, July 1978.
  • Heppner, J. P., et al., Early results from ISEE-1 electric field measurements, Space Sci. Rev., 22, No. 6, 777-789, doi:10.1007/BF00212623, Dec. 1978.
  • Maynard, N. C., et al., Magnetospheric observation of large sub-auroral electric fields, Geophys. Res. Lett., 7, No. 11, 881-884, doi:10.1029/GL007i011p00881, Nov. 1980.
  • Maynard, N. C., et al., The plasmaspheric electric field as measured by ISEE 1, J. Geophys. Res., 88, No. A5, 3991-4003, doi:10.1029/JA088iA05p03991, May 1983.
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