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Two-Frequency Beacon Receiver

NSSDCA ID: 1967-060A-02

Mission Name: Mariner 5
Principal Investigator:Prof. Von R. Eshleman


Both 423.3-MHz and the 2/17 subharmonic 49.8-MHz signals were transmitted from a 4.6-m steerable parabolic antenna at Stanford University to the two-frequency radio receiver on the spacecraft. The high-frequency signal served as a reference signal since its propagation time was not appreciably delayed. The low-frequency signal was delayed in proportion to the total electron content in the propagation path. On the spacecraft, a phase-locked receiver counted the beat-frequency zero crossings of the received signals to obtain measurements of phase-path differences. Differential delay of the group velocity was also observed, and these values were telemetered to the ground station. From calculated total electron content values, the ionospheric effect (up to a selected altitude obtained from other experimental techniques) can be subtracted to produce data describing the interplanetary electron content of the solar wind and its variations. The experiment operated nominally from launch to November 1967. For similar experiments covering other time periods, see Pioneers 6-9 (68-100A-03, 67-123A-03, 66-075A-04, and 65-105A-04). More detailed descriptions of the experiment can be found in J. Geophys. Res., v. 17, pp. 3325-3327, and in Radio Science, v. 6, pp. 55-63. NSSDC has all the data from this experiment.

Alternate Names

  • Mariner5/Two-FrequencyBeaconReceiver

Funding Agency

  • NASA-Office of Space Science Applications (United States)


  • Space Physics: Ionospheric Studies
  • Planetary Science: Fields and Particles

Additional Information

Questions and comments about this experiment can be directed to: Dr. David R. Williams



NameRoleOriginal AffiliationE-mail
Dr. Thomas A. CroftOther InvestigatorSRI
Prof. Von R. EshlemanPrincipal InvestigatorStanford

Selected References

  • Martin, D. P., Mariner 5 dual-frequency receiver, JPL, Calif. Inst. Technol., TR 32-1375, Pasadena, CA, Apr. 1969.
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