Aeolus’s telescope requires periodic collimation and refocussing. To this end, the Instrument Telescope Refocussing activity aims to improve the radiometric performance of the Atmospheric Laser Doppler Instrument (ALADIN)’s telescope by optimizing the throughput at the field stop, the smallest aperture where the return light has to pass. This is done through a change of the temperature settings on the telescope.
Strateole-2 is a French-US project supported by ESA that uses CNES superpressure balloons drifting around the globe to study the climate processes in the Tropical Tropopause Layer (TTL) and the lower stratosphere, helping Aeolus validation activities along the way.
ESA's Aeolus satellite has been returning profiles of Earth's winds since 3 September 2018, just after it was launched – and after months of careful testing these measurements are considered so good that the European Centre for Medium-Range Weather Forecasts is now using them in their forecasts.