• → European Space Agency

    • About Science & Technology

    • For Public

    • For Educators

    • ESA

    • Science & Technology

    • Cassini-Huygens

    • Missions
    • Show All Missions
    • Mission Home
    • Summary
    • Fact Sheet
    • Objectives
    • Mission Team
    • Orbit View

    • Science…

      • Saturn
      • Rings
      • Titan
      • Moons
      • Magnetosphere
    • Huygens Probe
    • Huygens
    • Instruments
    • Engineering
    • Cassini Orbiter
    • 3D Model
    • Instruments
    • Engineering
    • Mission Operations
    • Launch Vehicle
    • Launch Information
    • Approach and Arrival
    • Getting to Saturn
    • Huygens Probe Separation
    • Titan Surface Landing
    • Flybys
    • Science Operations
    • Data Archive
    • Resources
    • News Archive
    • Multimedia Gallery
    • Publication Archive
    • Calendar of Events
    • Services
    • Contact Us
    • Subscribe
    • Terms and Conditions
    • Bookmark and Share

    Instruments

    DWE: Doppler Wind Experiment

    The Doppler Wind Experiment (DWE) is a high-precision tracking investigation to determine wind direction and magnitudes in Titan's atmosphere. DWE measures the Doppler Shift or the Probe Relay Link Signal from the Huygens Probe to the Cassini Orbiter. The DWE-proper hardware consists of two Ultra-Stable Oscillators, one on the Probe and one on the Orbiter.


    DWE Scientific Objectives

    Primary Science Objectives

    • Determine the height profile of Titan zonal wind velocity over the altitude range from 0 - 160 km with an accuracy of ~ 1 ms-1


    Secondary Objectives

    • Measure Doppler fluctuations to determine the level and spectral index of turbulence and possible wave activity in Titan's atmosphere
    • Measure Doppler and signal level modulation to monitor Probe Descent Dynamics, including its rotation rate and phase, parachute swing and post-impact status

    DWE Ultra Stable Oscillator
    Physical and Electrical Characteristics

    Physical parameters

    Mass (g)

    1898

    radiation shielding: 150 g

    Dimensions (mm)

    170 × 117 × 119

    L × W × H

    DC power

    Warm-up power (W)

    < 18.4

    < 30 min

    DC consumption (mA)

    < 675

    System limit: 0.7 A

    Energy (Wh)

     

    worst case (minimum temp)

    Frequency parameters

    Output frequency (MHz)

    10

    ± 0.1 Hz

    Frequency long term drift

    1.4 × 10-9

    δf0/f0 over 3 hours

    Allen variation

     

    3 × 10-11

    τ = 1 s

    6 × 10-12

    τ = 10 s

    DISR: Descent Imager/Spectral Radiometer
    GCMS: Gas Chromatograph and Mass Spectrometer

    Last Update: 07 Dec 2005

    • Shortcut URL
    • http://sci.esa.int/jump.cfm?oid=31193
    • Related Articles
    • Introduction
    • Instruments in Brief
    • ACP: Aerosol Collector and Pyrolyser
    • DISR: Descent Imager/Spectral Radiometer
    • DWE: Doppler Wind Experiment
    • GCMS: Gas Chromatograph and Mass Spectrometer
    • HASI: Huygens Atmosphere Structure Instrument
    • SSP: Surface Science Package
    • Related Links
    • ACP: Aerosol Collector and Pyrolyser
    • DISR: Descent Imager / Spectral Radiometer
    • DWE: Doppler Wind Experiment
    • HASI: Huygens Atmospheric Instrument
    • SSP: Surface Science Package

    Connect with us

    • RSS
    • Youtube
    • Twitter
    • Flickr
    • Google Buzz
    • Livestream
    • Subscribe
    • App Store
    • ESA Science Twitter

    Follow ESA science

    • Copyright 2000 - 2013 © European Space Agency. All rights reserved.

    • Terms and Conditions