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Atmospheric Turbulence (MTUR)

NSSDCA ID: 1978-078E-06

Mission Name: Pioneer Venus Small Probe (North)
Principal Investigator:Dr. Richard T. Woo

Description

This experiment used the Deep Space Network (DSN) telemetry data. The objective was to measure and study the small-scale turbulence characteristics of the atmosphere of Venus. Information obtained included the variation of intensity of turbulence with altitude, wind velocity transverse to the line-of-sight path, and distribution of scale size in the atmosphere. These measurements contributed to an understanding of the atmosphere's circulation and dynamics.

The analysis of the scintillation of radio waves passing through the atmosphere was planned to give a measure of the turbulence. An estimate of the atmospheric structure constant was also possible. An investigation of the interference between the direct ray and a surface-reflected component was undertaken as means of assessing communications reliability for the design of future probe missions.

Turbulence in the atmosphere will cause inhomogeneity of the refractive index, resulting in scintillation of the radio signals. Recordings of the wideband (1 kHz width) S-band signals from the four probes, centered at 2291 to 2293 MHz (depending on the probe) from the 64-m DSN stations at Goldstone and Canberra, were used. The bandwidth was reduced to 2 Hz by using a digital phase lock loop procedure. The angles between the line-of-sight from the probes to Earth and the local Venus zenith ranged from 53 to 61 degrees. Fluctuation power spectra of amplitude were produced, the results indicated that amplitude scintillations were lower than the receiver noise level.

Alternate Names

  • MTUR
  • PioneerVenusSmallProbeNorth/MTUR

Discipline

  • Planetary Science: Atmospheres

Additional Information

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

 

Personnel

NameRoleOriginal AffiliationE-mail
Dr. Richard T. WooPrincipal InvestigatorNASA Jet Propulsion Laboratoryrwoo@mail1.jpl.nasa.gov

Selected References

  • Woo, R., et al., Measurements of turbulence in the Venus atmosphere deduced from Pioneer Venus mutiprobe radio scintillations, Science, 205, No. 4401, 87-89, doi:10.1126/science.205.4401.87, July 1979.
  • Colin, L., Ed., and D. M., Ed. Hunten, Pioneer Venus experiment descriptions, Space Sci. Rev., 20, No. 4, 451-525, doi:10.1007/BF02186463, June 1977.
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