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VLF Spectrograms on 35-mm Microfilm


Availability: Data Available from Experimenter

Time span: 1962-11-01 to 1972-09-01


This data set, generated by the principal investigator, consists of VLF data in a standard sonogram graphic form (frequency vs time). These sonograms on 35-mm film were prepared by the experimenter from analog data on magnetic tape, recorded at telemetry stations in real time. Approximately 1.6E4 passes were recorded, from which sonograms have been prepared for about 1500 passes. Most of the sonograms have been compiled from passes over the Ottawa station, although over half of the data observed were from other locations. By special arrangement, any data still available on tape (some older tapes have been erased) can be provided in limited quantities in sonogram form. Each pass processed into sonograms consists of three parts, each using different ranges on the frequency scales, i.e., nominally 0 to 20, 0 to 10, and 0 to 2.5 kHz. The time scale for the first two parts is 0.25 in./s, and is 0.125 in./s for the 0- to 2.5-kHz sonograms. Identification information is noted prior to each pass over a station. Universal time is shown at 10-s intervals along the edge of the sonograms. An analog representation of the VLF-receiver AGC level is also shown along the edge of the sonograms. These data can be made available for viewing by contacting the principal investigator, Dr. R. E. Barrington, Communications Research Centre, Dept of Communications, P.O. Box 11490, Station H, Ottawa, Ontario, Canada, K2H 8S2.

Alternate Names

  • VLF Spectrograms, Mfilm


  • Space Physics: Ionospheric Studies


  • 62-049A-03A

Additional Information



Questions and comments about this data collection can be directed to: Coordinated Request and User Support Office



NameRoleOriginal AffiliationE-mail
Mr. Frank H. PalmerGeneral ContactDepartment of Communications/Communications Research Centre
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