2.3.1 spase://SMWG/Instrument/SipleExperiment/VLF Siple Experiment VLF 2020-12-29T15:15:09 Receivers were set up at Siple station (75.93 deg. S, 84.25 deg. W geographic, corresponding to an invariant latitude of 60.4 deg. S, at L = 4.2), and near the geomagnetic conjugate point (first at Roberval, Quebec, Canada (48.52 deg. N, 72.23 deg. W) and in 1986 near Lake Mistissini, Canada (50.42 deg. N, 73.87 deg. W)). The receiver system consisted of two delta-shaped crossed loops mounted on a central 30-foot-high(~9 m) support with a base of 60 feet (18.3 m). These two mutually perpendicular antennas could be used for direction finding. In normal single-channel recording, one antenna is selected for minimum power line interference. A preamplifier at the base of the antenna boosts the received signal to an appropriate level for transmission to the recording equipment in the station. The receiving system includes provision for time marks, amplitude and frequency calibration, and automatic program control. Accurate timing of transmitted and received pulses were established by frequency standards at Siple and Roberval. These standards were calibrated regularly against Station WWV and are kept within a few milliseconds of UT. Complete results of the Siple station experiment are summarized in Helliwell, R. A.,(1988) Rev. Geophys., 26, 551-578, but analysis work on this dataset continued well after the experiment ended. These data were originally stored on Ampex magnetic tapes then converted over to a digitized format with some error correction applied as described by Li et al., (2014) JGR, 119,1837-1850. spase://SMWG/Person/Robert.A.Helliwell PrincipalInvestigator spase://SMWG/Person/Morris.Cohen ArchiveSpecialist http://waldo.world/description-of-data/ SpectralPowerReceiver Siple Experiment spase://SMWG/Observatory/SipleExperiment