Observations and analysis of phase scintillation of spacecraft signal on the interplanetary plasma

¹ Joint Institute for VLBI in Europe, Oude Hogeevensedijk 4, 7991 PD Dwingeloo, The Netherlands
e-mail: molera@jive.nl
² Aalto University Metsähovi Radio Observatory, 02540 Kylmälä, Finland
³ Sternberg Astronomical Institute, Lomonosov Moscow State University, 19992 Moscow, Russia
⁴ Department of Astrodynamics and Space Missions, Delft University of Technology, 2629 HS Delft, The Netherlands
⁵ Shanghai Astronomical Observatory, Chinese Academy of Sciences, 200030 Shanghai, PR China
⁶ Max Planck Institute for Radio Astronomy, 53151 Bonn, Germany
⁷ National Astronomical Observatory, Astronomical Centre of Yebes, 28911 Leganes, Madrid, Spain
⁸ Federal Agency for Cartography and Geodesy, Geodetic Observatory of Wettzell, 60598 Frankfurt Am Main, Germany
⁹ Chalmers University of Technology, Onsala Space Observatory, 41258 Göteborg, Sweden
¹⁰ Hartebeesthoek Radio Astronomy Observatory, 1740 Krugersdorp, South Africa
¹¹ National Institute for Astrophysics, RadioAstronomy Institute, Radio Observatory Medicina, 75500 Medicina, Italy
¹² E-geos S.p.A, Space Geodesy Center, Italian Space Agency, 75100 Matera, Italy
¹³ Xinjiang Astronomical Observatory, Chinese Academy of Sciences, 830011 Urumqi, PR China
¹⁴ Yunnan Astronomical Observatory, Chinese Academy of Sciences, 650011 Kunming, PR China

Received: 28 October 2013
Accepted: 5 February 2014

Abstract

Aims. The phase scintillation of the European Space Agency’s Venus Express (VEX) spacecraft telemetry signal was observed at X-band (λ = 3.6 cm) with a number of radio telescopes of the European Very Long Baseline Interferometry (VLBI) Network in the period 2009–2013.

Methods. We found a phase fluctuation spectrum along the Venus orbit with a nearly constant spectral index of −2.42 ± 0.25 over the full range of solar elongation angles from 0° to 45°, which is consistent with Kolmogorov turbulence. Radio astronomical observations of spacecraft signals within the solar system give a unique opportunity to study the temporal behaviour of the signal’s phase fluctuations caused by its propagation through the interplanetary plasma and the Earth’s ionosphere. This gives complementary data to the classical interplanetary scintillation (IPS) study based on observations of the flux variability of distant natural radio sources.

Results. We present here our technique and the results on IPS. We compare these with the total electron content for the line of sight through the solar wind. Finally, we evaluate the applicability of the presented technique to phase-referencing VLBI and Doppler observations of currently operational and prospective space missions.