VLF electric and magnetic fields observed in the auroral zone with the Javelin 8.46 Sounding Rocket

Results of the Javelin 8.46 VLF electric and magnetic fields experiment flown from Fort Churchill, Canada, on May 25, 1968, are discussed. This experiment carried three orthogonal magnetic loop antennas, three orthogonal long (3.16 meters) electric dipoles, two short (42 cm) electric dipoles, and six wideband (30 Hz to 10 kHz) receivers for amplifying signals from the various VLF antennas. Intense noise bursts with frequencies less than about 1.5 kHz were observed on all the electric antennas below 500-km altitude, but not on the loop antennas. The precession and spin modulation of these noise bursts suggest that the noise is generated by an interaction between the payload and the surrounding plasma. High-frequency electrostatic noise bursts, from 5 to 30 kHz, were observed throughout the flight. These noise bursts, similar in some respects to lower-hybrid-resonance noise commonly observed with satellite VLF electric field experiments, also appear to involve an interaction between the payload and the surrounding plasma. Attenuation bands at harmonics of the proton gyrofrequency were also found in the frequency spectra of electric field noise observed during a portion of the flight.