On 22 August 2018, ESA’s Aeolus satellite was launched and within a week came the moment our engineers had all been waiting for: switching on of the lidar instrument and its first emission of ultraviolet pulses. It is these pulses which enable Aeolus to take a 0km-25km slice of the atmosphere and, using a laser and Doppler Effect, make an accurate wind-map at all latitudes with a 250m resolution. The first results didn’t disappoint.
In the first several months of operations, Aeolus continued to demonstrate its lidar was up to the job, but then signs of energy loss were observed on the laser transmitter, threatening to compromise data quality. But, being a test satellite, a back-up laser had been built in to the design and the Airbus and ESA teams worked together to make a successful switch over to the second laser. Far from being seen as a failure, the first laser nevertheless notched up almost one billion shots and provided a vital first dataset of its kind.
Since then, Aeolus has consistently delivered high quality data and has gone above and beyond its original mission. From stepping in to provide missing wind measurements that used to be taken by planes before covid, to its data being deemed so valuable that it has been adopted for daily weather forecasting. Indeed, the volume of data also clearly sets it apart, since this one satellite is delivering more wind data than all existing ground-based measuring systems. And after three years in orbit Aeolus has now exceeded its design lifetime and is still going strong.
Philippe Pham, Airbus’ Head of Earth Observation & Science concludes: “That Aeolus data is now being used as part of the operational weather forecasting flow demonstrates its quality and reliability. Built as a one-off research mission, Aeolus is truly exceeding all expectations – testament to our engineers’ skill and determination in developing this new technology. Its success also paves the way for a possible future fleet of Doppler wind Lidar satellites in space.”
Not bad for a test satellite.