Instrument Overview
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    Coherently related radio signals were transmitted by the spacecraft at
    wavelengths of 8 cm and 32 cm. These passed through the ionosphere of
    Venus before being received at the Evpatoria station (in the Crimean
    region of what is now Ukraine) of the Soviet Deep Space Communication
    Center. The standard equipment provided signal amplification,
    heterodyning, and filtering. Next, the received transmissions were fed
    into a dispersion interferometer, which used a closed-loop system to
    perform narrow-band filtering in order to isolate the desired signals.
    Amplitude and phase of both signals was recorded. Ionospheric electron
    densities were obtained from these data products using standard
    techniques for radio occultation experiments. The leader of the radio
    occultation experiment was N. A. Savich and one of the experimenters
    was A. L. Gavrik.