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Electric Field Detector

NSSDCA ID: 1968-100A-07

Mission Name: Pioneer 9
Principal Investigator:Dr. Frederick L. Scarf


Electrostatic and electromagnetic plasma waves were measured in the solar wind near 1 AU using an unbalanced electric dipole antenna. The 423-MHz Stanford University antenna, which served as the sensor, was capacitively coupled to three telemetry channels. Channel 1 was a 15% bandpass filter centered at 400 Hz, and channel 2 was a 15% bandpass filter centered at 30 kHz. These channels were each sampled 64 times per telemetry sequence. Channel 3 was a broadband 100-Hz to 100-kHz channel. The broadband channel was fed into a count-rate meter that measured the number of positive-going pulses per unit time having amplitudes large enough to cross the present trigger level. The trigger level was varied through eight steps, eight times per telemetry sequence. The trigger levels, together with the count rate at each level, gave a measure of the broadband power spectrum. Due to ambient conditions, these data usually represented the power at about 100 Hz. The telemetry sequence was repeated over time intervals from 7 min 28 s to 472 min 52 s.

Alternate Names

  • Pioneer9/ElectricFieldDetector

Funding Agency

  • NASA-Office of Space Science (United States)


  • 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
Dr. Robert W. FredricksOther InvestigatorTRW Systems Group
Dr. Ira M. GreenOther InvestigatorTRW Systems Group
Mr. Gaines M. CrookOther InvestigatorGaines M. Crook Associates
Dr. Frederick L. ScarfPrincipal InvestigatorTRW Systems Group
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