From its 400 km orbit, the European satellite Aeolus (named after the Greek god of wind) was launched in August 2018 by the European Space Agency (ESA). It generates wind profiles from all around the planet up to an altitude of 30 km. The incredibly accurate observations is based on a radically new method which doesn’t include tracking cloud movement or monitoring sea surface roughness. Instead, Aeolus uses laser technology with its unique Aladin instrument (Atmospheric Laser Doppler Instrument).

Aladin is a Lidar/Doppler instrument. It uses a high-power laser emitting ultraviolet light pulses (335 nm). The light is then reflected by molecules, aerosols, and cloud particles in the atmosphere, and bounces back to the satellite’s 1.5 m telescope to be analysed by highly accurate sensors. These observations are valuable for climatologists, with a view to improving weather forecasts, especially in the southern hemisphere’s tropical region where ground-based weather stations are scarce.

Aeolus was selected in 1999 as one of the two flagship missions in ESA’s Living Planet programme. French scientists and laboratories (such as LATMOS, LMD, or IPSL) contributed their world-renowned expertise in lidar technology to the project. CNES coordinated with ESA to support French research teams involved in the project’s design and development. CNES also contributed during the mission’s calibration/validation and operational stages (including operational meteorological model integration) starting in 2018. Airbus Defence & Space is responsible for developing and building the Aeolus satellite and its Aladin instrument.