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ADM-Aeolus: Wind Measuring Satellite


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#1    Waspie_Dwarf

Waspie_Dwarf

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Posted 08 June 2007 - 01:19 PM

ESA's wind mission ADM-Aeolus

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ADM-Aeolus is an Earth Explorer mission currently planned for launch in 2008 and due to chart the Earth's global wind field profiles with a lidar.

Credits: ESA - AOES Medialab


The Earth Explorer Atmospheric Dynamics Mission (ADM-Aeolus) will provide global observations of wind profiles from space to improve the quality of weather forecasts, and to advance our understanding of atmospheric dynamics and climate processes.

Although there are several ways of measuring wind from a satellite, ADM-Aeolus will utilise the active Doppler Wind Lidars (DWL) method. This is the only method that has the potential to provide the required data globally, from direct wind observations. In addition, a DWL will provide information on cloud top heights, vertical distribution of cloud, aerosol properties, and wind variability. This information is a useful by-product of the DWL method.

An improved model of the Earth’s climate and atmosphere will lead to progress in numerical weather prediction (NWP), especially concerning long-term forecasting. It is widely recognised that a new global atmospheric observing system, such as ADM-Aeolus, will have a great effect upon operational weather forecasting. The provision of detailed wind profiles will also benefit scientists involved with climate research, allowing for greater accuracy in the numerical modelling of tropical regions in particular.


Source: ESA - Living Planet Programme

"Space is big. Really big. You just won't believe how vastly, hugely, mind-boggingly big it is. I mean, you may think it's a long way down the street to the chemist, but that's just peanuts to space." - The Hitch-Hikers Guide to the Galaxy - Douglas Adams 1952 - 2001

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#2    Waspie_Dwarf

Waspie_Dwarf

    Space Cadet

  • 33,893 posts
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  • We are all in the gutter, but some of us are looking at the stars.

    Oscar Wilde

Posted 08 June 2007 - 01:33 PM

Critical laser components stand the test of time for ESA's wind mission Aeolus

6 June 2007

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ADM-Aeolus transmitter laser. The two amplifier units (the two rectangular blocks) each contain eight laser diode stacks.

Credits: Galileo Avionica

The ADM-Aeolus (Atmospheric Dynamics Mission) project has just passed another milestone with the confirmation that the laser diode stacks, which are the core components of the mission's instrument, have successfully passed their long-lifetime test - demonstrating that they will endure the three years of operation in space.

These complex electro-optical components have never before been qualified in Europe for long operation in space. However, after an intensive period of development and testing, the laser diode stacks, which were manufactured by Quantel Laser Diodes (QLD), have proved that they can be used in the mission. This marks a significant step forward for the development of the ADM-Aeolus mission.  

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ADM-Aeolus will be the first space mission to measure wind profiles on a global scale.

Credits: ESA - AOES Mediala

Due for launch in 2009, ESA's wind mission, often referred to as just 'Aeolus', will be the first-ever satellite to directly observe wind profiles from space. Demonstrating new laser technology, this Earth Explorer mission aims to improve the quality of weather forecasts, and advance our understanding of atmospheric dynamics and climate processes.

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Schematic view of a space-borne lidar. A short laser pulse is emitted towards the atmosphere where air molecules and particles reflect a small portion of the light pulse back to the lidar. A telescope collects the light and directs it to the receiver. The signal is recorded as a function of time to determine the altitude of the scattering layers.

Credits: ESA


Aeolus will probe the atmosphere with a highly sophisticated instrument called the Atmospheric Laser Doppler Instrument (ALADIN) to measure wind velocity with unequalled accuracy. The instrument emits short and high-energy pulses towards the atmosphere and analyses the Doppler shift of the backscattered signal for different altitudes.

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The complete ADM-Aeolus laser before being sealed for flight configuration.

Credits: Galileo Avionica

The laser diode stacks are at the heart of the ALADIN transmitter laser. A total of 18 laser diode stacks are used to generate the powerful light pulses in the ultraviolet (355 nm) with a peak power over extremely short 'bursts' of about five million watts. Since the laser emits 100 light pulses per second, several billion light pulses will be generated over the three-year lifetime of the Aeolus mission.


Needless to say, the laser diode stacks are crucial to the operation of the mission so ensuring that they will continue to generate these light pulses through the duration of the space mission has been a priority for scientists and engineers working on Aeolus. Although each laser diode stack is capable of emitting light pulses with a peak power of over 1000 W, they have been de-rated to 750 W for Aeolus to increase their lifetime. Over the lifetime of the mission, the output power will be kept constant but the drive current will be increased to compensate for the aging of the diode emitters.


The success of the laser diode stack lifetime tests means that the Aeolus mission can take another important step towards completion and eventual launch in 2009.


Source: ESA - Living Planet Programme

"Space is big. Really big. You just won't believe how vastly, hugely, mind-boggingly big it is. I mean, you may think it's a long way down the street to the chemist, but that's just peanuts to space." - The Hitch-Hikers Guide to the Galaxy - Douglas Adams 1952 - 2001

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