Radio Science

Radio scintillations during occultations by turbulent planetary atmospheres


  • Richard Woo,

  • Akira Ishimaru,

  • Fang-Chou Yang


The radio occultation experiment which uses the radio link between the earth and spacecraft passing behind planets has proven to be an important method for remote sensing turbulence in planetary atmospheres. In this paper we examine the effects of defocusing and anisotropic irregularities on the turbulence-induced fluctuations of the radio occultation signal. We employ Rytov's method along with geometrical optics to study the frequency spectra and coherences of the log amplitude and phase fluctuations of spherical waves operating at one as well as two frequencies. Comparison with the Mariner 5 2.3-GHz measurements shows good agreement with the theoretical results.