Satellite-born ultraviolet laser detector profiles the world’s winds
Part of the Atmospheric Laser Doppler Instrument (ALADIN), the ultraviolet laser detector uses a unique Charge Coupled Device (CCD) type detector contracted by Airbus Defence & Space, Toulouse, in 2003, and delivered by Teledyne e2v in 2005. The CCD69 ultraviolet detector on-board the Aeolus will help gather wind data profiles of the Earth to improve the accuracy of global weather forecasts.
Traditional methods to gather this type of data involve deploying weather balloons, cloud tracking, and monitoring temperature and surface winds. Instead, the Aeolus satellite’s ALADIN will emit an ultraviolet laser beam through the Earth’s atmosphere and measure the reflected return signal from particles, or aerosols in the atmosphere.
The CCD69 ultraviolet detector was developed in collaboration with Airbus Defence & Space and ESA, simultaneously measuring the distance of the returned ultraviolet laser pulse to resolve the altitude of aerosols in the atmosphere, and the Doppler shift that equates to the wind speed at each altitude. The returned signal is typically extremely weak, however the detector has the capability to add together a number of returned pulses to improve the accuracy of the measurements. Aeolus is the first satellite of its kind to utilize this type of technology in space.
The detector consists of a 16×16 pixel CCD with a novel storage region that accumulates the signal from several successive laser pulses. The detector is housed in a hermetically sealed package with an integrated Thermoelectric Cooler (TEC) that uses the Peltier effect to transfer heat away from the sensor. The CCD detector is optimized through a back-thinning process to provide a very high detection efficiency at the laser wavelength of 355nm. The Aeolus satellite is now in low orbit and will have a life span of approximately three years.
Teledyne e2v – www.teledyne-e2v.com
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