NSSDCA ID: 1978-051A-22
Mission Name: Pioneer Venus OrbiterThe Orbiter Turbulence Experiment (OTUR) made use of the S-band and X-band radio signals for data measurements. The objectives of the experiment were to measure (1) the intensity variation of turbulence with altitude, (2) planetary latitude and longitude, and (3) the distribution of scale sizes in the atmosphere. It is designed to observe turbulence of scale sizes smaller than 10 km in the Venus atmosphere above 34 km, in order to study the global distribution of turbulence in the atmosphere. It will also measure electron density variations in the Venus ionosphere.
The experiment uses the existing S- and X-band radio system on the Pioneer Venus Orbiter to study scintillations in the radio signals as they pass through the atmosphere and ionosphere before and after occultations. The ground stations make wide-band linear recordings in the frequency interval containing the signal. The signals can be examined for scintillations, indicating variations in density in the atmosphere due to turbulence.
1.09 m diameter high-gain parabolic dish antenna mounted on a 2.9 meter mast on the top deck of the spacecraft. It is despun from the rotating spacecraft so that it always faces Earth. It is also capable of being pointed up to 15 degrees from the Earth during Venus atmospheric occultations, to account for the refraction of the beam as it passed through the atmosphere. It operated in both S and X bands. At S-band, the antenna beam is 7.6 degrees. The orbiter carries a 750 mW X band (8.415 GHz) transmitter and a 2.295 GHz S band transmitter. The frequencies are set so that the X-band frequency is 11/3 of the S band.
Questions and comments about this experiment can be directed to: Dr. David R. Williams
Name | Role | Original Affiliation | |
---|---|---|---|
Dr. Richard T. Woo | Principal Investigator | NASA Jet Propulsion Laboratory | rwoo@mail1.jpl.nasa.gov |