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Plasma Frequency, Electron Temperature, and Thunderstorm Noise Plots


Availability: At NSSDC, Ready for Offline Distribution (or Staging if Digital)

Time span: 1967-05-05 to 1968-04-14


These data consist of plots from the Langmuir Probe, Terrestrial Radio (Thunderstorm) Noise, and Radio Frequency Capacitance Probe instruments. They are a graphical representation of the digital data available in NSSDC collection SPIO-00061.

There are usually five frames of data for each pass. The title to each frame gives telemetry station name, approximate universal time in hours, satellite orbit number, day number (01 January 1967 is day number 1), right ascension and declination of the satellite spin axis, corrected Zurich sunspot number, and Kp index.

The first frame shows a global map with the satellite path superimposed. Shown also on this map, are the limits of radio visibility for the six frequencies of interest, and the area of the Earth in darkness.

The second frame (and the fourth, which is a continuation of the second) shows plots of measured radio noise intensity in dB vs latitude and time, for each pair of receivers in the frequency bands at 15, 10, and 5 MHz. These frames also show plots of pulse counts/s from each pair of receivers. The receiver frequencies in units of MHz are 15.004 and 14.996, 10.002 and 9.998, and 5.002 and 4.998. Six maps are given at the end of each day's passes. Three maps, one each for the 5-, 10-, and 15-MHz paired receivers, show northbound passes at the stated local mean time, and three maps show the southbound passes at another local time. The circled or bracketed regions along an orbit trace show where direct reception of signals affecting both receivers in a band possibly originated.

The third frame (and the fifth, which is a continuation of the third) contains the plasma frequency and electron temperature data.

Additional data on these frames include plots of the satellite height (km) vs latitude and time, the critical frequency fxF2 (MHz), and the height of the F2 maximum (km). These latter two parameters were obtained from NOAA prediction maps.

Alternate Names

  • Plasma Freq, Elect. Temp, Thunderstorm Noise, microfilm


  • Earth Science: Atmospheric Dynamics
  • Space Physics: Ionospheric Studies


  • 67-042A-01B
  • 67-042A-04B
  • 67-042A-06B

Additional Information



Questions and comments about this data collection can be directed to: Dr. Dieter K. Bilitza



NameRoleOriginal AffiliationE-mail
Prof. J. SayersData ProviderUniversity of Birmingham
Mr. John A. MurphyGeneral ContactRutherford Appleton Laboratory

Selected References

  • Wager, J. H., The University of Birmingham electron density and temperature experiments on the Ariel 3 satellite, Radio Electron. Eng., 35, 55-63, doi:10.1049/ree.1968.0011, Jan. 1968.
  • Ariel 3 symposium, Proc. of Ariel 3 Symp., Goddard Space Flight Center, Greenbelt, Md., May 22-23, 1968
  • Horner, F., and R. B. Bent, Measurement of terrestrial radio noise, Proc. Roy. Soc. A., 311, 527-542, doi:10.1098/rspa.1969.0133, 1969.
  • Harden, B. N., and V. A. W. Harrison, Satellite-borne equipment for a global survey of terrestrial radio noise, Radio Elect. Engin., Unnumbered, Mar. 1968.
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