Measurement and reconstruction of laser shots of the Aeolus satellite in the Pierre Auger Observatory

The Pierre Auger Observatory is a large-scale experiment for the detection of ultra-high-energy cosmic rays. To this end, a combination of surface detectors as well as fluorescence telescopes is used to measure extensive air showers initiated by cosmic-ray particles in the atmosphere. Aeolus is a satellite, operated by the ESA, with the purpose of measuring global wind profiles. To achieve this, it uses a UV-lidar which emits laser beams towards the surface of the Earth. When the satellite passes over the Pierre Auger Observatory, light scatters off the laser beam in the atmosphere which can be detected by the Fluorescence Detector. The laser data taken by the Observatory allowed for a reconstruction of the laser tracks for several overpasses each year since its first appearance in 2019. The reconstructed laser tracks provide an interesting approach to study the aerosol content of the atmosphere above the Observatory, as well as a novel way to perform ground-truthing for space-based lidards.

In this presentation, we will explain the methods used to reconstruct laser tracks from the Fluorescence Detector data, show some results of this reconstruction and introduce a possible application of the data for the measurement of aerosols.