PLASMA-INDUCED INTERFERENCE IN SATELLITE v.l.f. RECEIVERS

Section: E Spacecraft Generated Interferencesupporting

confidence: 73%

Initial observations of VLF electric and magnetic fields with the Injun 5 satellite

Gurnett¹,

Pfeiffer²,

Anderson³

et al. 1969

“…We propose that ac noise signals appearing on the solar panels drive fluctuations in antenna floating potential (•) and that these variations in (I, then develop across the input circuit as VLF noises. This type of in-orbit interference is very common for electric field antennas, and unbalanced dipoles are especially susceptible to this form of degradation [Osborne et al, 1967;Scarf, Fredricks, and Crook, 1968]. The effect does not occur in the absence of plasma, and when the solar panels are dark, the cells are biased off so that noise s;.gnals do not couple to the antenna.…”

Section: One Example Of the Increase In E• Caused By Suprathermal Elementioning

confidence: 99%

Initial results of the Pioneer 8 VLF Electric Field Experiment

Scarf¹,

Crook²,

Green³

et al. 1968

The Pioneer 8 spacecraft was launched into an outbound heliocentric orbit on December 13, 1967. The payload includes a simple VLF electric field detector that uses the 423‐MHz antenna supplied for the Stanford radio propagation experiment. Broadband signals in the frequency range 0.1–100 kHz are examined by performing a pulse height analysis of the waveform, and wave amplitudes are also measured in bandpass channels centered at 0.4 and 22 kHz. It is found that low‐frequency electric field oscillations can always be detected in the solar wind, and that the amplitudes vary with changing interplanetary conditions. Large amplitude high‐frequency noise bursts are also detected sporadically, and we identify these as electron plasma oscillations in the solar wind.

Detection of electromagnetic and electrostatic waves on OV3-3

Scarf¹,

Fredricks²,

Crook³

1968

The TRW Systems electric field experiment on the USAF‐Aerospace Corporation spacecraft OV3‐3 (1966–70A) has one broadband channel and four bandpass channels covering the frequency range 20 Hz to 7.35 kHz, plus an onboard E, B correlator, which operates at a frequency of 400 Hz. The E‐field sensor is a short boom‐mounted asymmetric dipole that detects electric oscillations in the spacecraft equatorial plane. Examination of the angular distributions, and the loop and correlator response, allows electrostatic and electromagnetic waves to be distinguished. Details of the method of operation of the electric field sensor and related instrumentation are given, and preliminary results from the bandpass channels are displayed and discussed.