Aeolus mission payload   The wind is observed orthogonal to the satellite ground-track, pointing 35º off-nadir, away from the Sun. Wind profiles are accumulated over at least 20 individual measurements before being downlinked to the ground for further averaging. The typical averaging distance is 90 km, which corresponds to 12 seconds.   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.   The Atmospheric Laser Doppler Instrument, or Aladin for short, comprises a powerful laser, a large telescope and a very sensitive receiver. Last update: 23 March 2012