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Conclusions/References

The Huygens Doppler Wind Experiment is designed to determine the velocity of Titan's zonal winds. The wind is measured over a height range from 0 - 160 km from its Doppler signature on the Probe's radio relay signal to the Cassini Orbiter. The stringent frequency stability required for the DWE measurement is assured by (a) generating the transmitted signal with a externally supplied ultrastable oscillator (TUSO), and (b) providing the receiver with an identical ultrastable external oscillator (RUSO). Information on probe dynamics (spin rate, spin phase, parachute swing) and large-scale turbulence in the Titan atmosphere are secondary objectives of the investigation. The reconstructed probe trajectory using DWE data provides the best estimate of Huygens' final place of rest on Titan.

Acknowledgements


This paper presents results of a research project partially funded by the Deutsche Agentur für Raumfahrtangelegenheiten (DARA) GmbH under contract 50 OH 9207. The responsibility for the contents is assumed by the authors.

References


Allison, M 1992, A preliminary assessment of the Titan planetary boundary layer, in Symposium on Titan, ESA SP-338, 113-118.
Allison, M, Del Genio, A D & Zhou, W 1994, Zero potential vorticity envelopes for the zonal-mean velocity of the Venus/Titan atmospheres, J. Atmos. Sci. 51, 694-702.
Atkinson, D H 1989, Measurement of planetary wind fields by Doppler monitoring of an atmospheric entry vehicle, Ph.D. Thesis, Washington State University, Pullman WA, 609 pp.
Atkinson, D H, Pollack J B & Seiff A 1990, Measurement of a zonal wind profile on Titan by Doppler tracking of the Cassini entry probe, Radio Sci. 25, 865-882.
Bird, M K 1995, Atmospheric attenuation of the Huygens S-Band Radio Signal during the Titan Descent, in Huygens: Science Payload and Mission, ESA-SP 1177 (this volume).
Coustenis, A 1990, Spatial variations of temperature and composition in Titan's atmosphere: Recent results, Ann. Geophysicae 8, 645-652.
Del Genio, A D, Zhou, W & Eichler, T P 1993, Equatorial superrotation in a slowly rotating GCM: Implications for Titan and Venus, Icarus 101, 1-17.
Flasar, F M, Allison M & Lunine, J I 1995, Huygens Probe wind drift: science issues and recommendations, in Huygens: Science Payload and Mission, ESA-SP 1177 (this volume).
Flasar, F M & Conrath, B J 1990, Titan's stratospheric temperatures: A case for dynamical inertia?, Icarus 85, 346-354.
Flasar, F M, Samuelson, R E & Conrath, B J 1981, Titan's atmosphere: temperature and dynamics, Nature 292, 693-698.
Flury, W 1986, Cassini Mission - Titan Probe trajectory in The Solid Bodies of the Outer Solar System, ESA-SP 242, 237-281.
Hanel, R et al. 1981, Infrared observations of the Saturnian system from Voyager 1, Science 212, 192-200.
Hinson, D P & Tyler, G L 1983, Internal gravity waves in Titan's atmosphere observed by Voyager radio occultation, Icarus 54, 337-352.
Hourdin, F, Le Van P, Talagrand, O, Courtin, R, Gautier, D & McKay, C P 1992, Numerical simulation of the circulation of the atmosphere of Titan, in Symposium on Titan, ESA SP-338, 101-106.
Hubbard, W B et al. 1993, The occultation of 28 Sgr by Titan, Astron. Astrophys. 269, 541-563.
Lebreton, J-P 1995, Huygens science overview and mission description, in Huygens: Science Payload and Mission, ESA-SP 1177 (this volume).
Lellouch, E, Coustenis, A, Gautier, D, Raulin, F, Dubouloz, N, and Frère, C 1989, Titan's atmosphere and hypothesized ocean: a reanalysis of the Voyager 1 radio-occultation and IRIS 7.7-m data, Icarus 79, 328-349.
Lindal, G F, Wood, G E, Holtz, H B, Sweetnam, D N, Eshleman V R & Tyler G L 1983, The atmosphere of Titan: An analysis of the Voyager 1 radio occultation measurements, Icarus 53, 348-363.
Ott, S 1991, Analysis of targetting requirements for the Huygens mission, ESTEC Working Paper EWP-1640, 156pp.
Pollack, J B, Atkinson, D H, Seiff, A & Anderson, J D 1992, Retrieval of a wind profile from the Galileo Probe telemetry signal, Space Sci. Rev. 60, 143-178.
Smith, P H, Karkoschka, E & Lemmon, M 1992, Titan's North-South asymmetry from HST images, Bull. Am. Astron. Soc. 24, 950.
Smith, P H, Lemmon, M T, Lorenz, R D, Sromovsky L R, Caldwell J J, & Allison, M D 1995, Titan's surface, revealed by HST imaging, Icarus (in press).
Smith, P H, Lemmon, M T, Caldwell J J, Allison, M D, & Sromovsky L R 1994, HST imaging of Titan, Bull. Am. Astron.\ Soc. 26, 1181.
Strobel, D F & Sicardy, B, 1995, Wind shear and wind gust models, in Huygens: Science Payload and Mission, ESA-SP 1177 (this volume).
Toon, O B, McKay, C P, Courtin, R & Ackerman, T P 1988, Methane rain on Titan, Icarus 75, 255-284.
Tyler, G L, Eshleman, V R, Anderson, J D, Levy, G S, Lindal, G F, Wood, G E & Croft T A 1981, Radio science investigations of the Saturn system with Voyager 1: Preliminary results, Science 212, 201-206.



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