The Sheffield University v.l.f. experiment on the satellite Ariel 3

Abstract

The Ariel 3 satellite (orbital inclination 80°, mean altitude 550 km) was launched from Vandenberg, California on 5 May 1967. One of the five experiments carried by the spacecraft was a synoptic study of v.l.f. phenomena above the ionosphere using a v.l.f. receiver with loop aerial. The peak, mean and minimum signals at 32, 96 and 16 kHz are measured in each 28 second period around the orbit. At 16 kHz wide (Δf = 1 kHz) and narrow (Δf = 100 Hz) band channels are used to distinguish c.w. transmissions from GBR (Rugby) from natural noise-like signals such as hiss. The measurements are stored on the satellite tape recorder and telemetered to ground at an appropriate Stadan station. The factors governing the choice of receiver parameters are discussed. The equipment and technical problems encountered are described.