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A Measurement of Titan´s Zonal Winds by the Huygens Doppler Wind Experiment:

A Measurement of Titan´s Zonal Winds by the Huygens Doppler Wind Experiment:. Michael Bird (Radiostronomisches Institut, Universität Bonn) And the DWE Team. DPS Cambridge - Paper 2.01I Monday, 5 September 2005. The DWE Team. M.K. Bird, R. Dutta-Roy, Y. Dzierma

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A Measurement of Titan´s Zonal Winds by the Huygens Doppler Wind Experiment:

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  1. A Measurement of Titan´s Zonal Winds by the Huygens Doppler Wind Experiment: Michael Bird (Radiostronomisches Institut, Universität Bonn) And the DWE Team DPS Cambridge - Paper 2.01I Monday, 5 September 2005

  2. The DWE Team • M.K. Bird, R. Dutta-Roy, Y. Dzierma Radioastronomisches Inst., Univ. Bonn, Auf dem Hügel 71, 53125 Bonn, Germany • M. Allison NASA Goddard Inst. for Space Studies, 2880 Broadway, New York, NY 10025 • D.H. Atkinson Dept. of Elec. & Computer Engineering, Univ. of Idaho, Moscow, ID 83844 • S.W. Asmar, W.M. Folkner, D.V. Johnston, R.A. Preston Jet Propulsion Laboratory, Caltech, 4800 Oak Grove Dr, Pasadena, CA 91109 • P. Edenhofer Institut für HF-Technik, Universität Bochum, 44780 Bochum, Germany • D. Plettemeier Elektrotechnisches Institut, Technische Univ. Dresden, 01062 Dresden, Germany • G.L. Tyler Center for Radar Astronomy, Stanford University, Stanford, CA 94305 • L.I. Gurvits, S.V. Pogrebenko, I.M. Avruch Joint Inst. for VLBI in Europe, P.O. Box 2, 7990 AA Dwingeloo, The Netherlands Huygens DWE

  3. DWE Concept (1) • Goal: In situ determination of zonal wind speed along Huygens descent path • Approach: Record Doppler effect on Huygens carrier signal => radial velocity Huygens DWE

  4. DWE Concept (2) • Input parameters: • Huygens descent speed, • Huygens meridional speed • Huygens starting position • Cassini position & velocity • Earth-based station position & velocity Huygens DWE

  5. DWE Hardware Ultra-stable Oscillators (USOs) • TUSO on Huygens Probe + • RUSO in Huygens Receiver on Cassini Huygens DWE

  6. Huygens Signal paths Cassini TCXO TCXO Channel B Huygens Receivers Huygens Data TCXO TUSO Channel A TCXO RUSO TCXO RUSO Huygens Probe NO POWER “Channel C” Earth Huygens DWE

  7. DWE from Earth: Geometry Titan Disk • Huygens antenna pointed only ~30° from Earth • Better SNR than for VLA detection of Galileo Probe at Jupiter • Probe-Earth vector projection onto horizontal nearly antiparallel to Probe-Orbiter projection 20º Huygens DWE

  8. Huygens Radio Tracking Net GBT VLBA OV PT VLBA KP MK MK Parkes 10:18 UTC-GRT 12:30 UTC-GRT Huygens DWE

  9. Huygens Earth-Based Network Huygens DWE

  10. GBT Parkes Huygens DWE

  11. 10:18:15 UTC-GRT 10 GBT: 14 Jan 2005 Huygens! (~ -171 dBm) just noise Flux density  125 Jy Huygens DWE

  12. Huygens Frequency: GBT + Parkes Cassini loss of link 26-min gap Parkes GBT Huygens DWE

  13. Huygens Frequency: GBT + predicts 80-s gaps (VLBI) Huygens DWE

  14. Huygens Frequency: Parkes + Predicts 80-s gaps (VLBI) predicted impact f = +26.4 Hz Huygens DWE

  15. Zonal Wind Velocity Huygens DWE

  16. Zonal Wind Height Profile Huygens DWE

  17. DWE: Preliminary Results 1. Zonal winds above boundary layer are PROGRADE 2. First in situ confirmation of TITAN’S SUPERROTATION 3. Huygens eastward drift: 3.75º (~166 km) 4. Low-velocity layer between 60-100 km • Stong positive/negative wind shear • Unexpected, presently unexplained 5. Considerable turbulence above 100 km 6. Near surface winds are weak (~1 m/s) Huygens DWE

  18. Huygens Ground Track Determination:A Comparison of DWE and DISR Results R. Dutta-Roy, B. Rizk, S.W. Asmar, D.H. Atkinson, M.K. Bird, M.W. Bushroe, E. Karkoschka, E.A. McFarlane, C. See, M.G. Tomasko, and the DWE and DISR Teams DPS Cambridge - Poster 45.09 Wednesday, 7 September 2005

  19. A Preliminary Meteorological Interpretation of Correlated Huygens DWE and HASI Data M. Allison, F. Ferri, M.K. Bird, M. Fulchignoni, S.W. Asmar, D.H. Atkinson, G. Colombatti, G.L. Tyler and the DWE and HASI Experiment Teams DPS Cambridge - Poster 45.03 Wednesday, 7 September 2005

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