The new generation of planned earthbound Extremely Large Telescopes (ELT) aims at an excellent image quality in a large field of view. Such systems rely on Adaptive Optics (AO) systems that correct optical distortions caused by atmospheric turbulences. To achieve a satisfying correction, the deformations of optical wavefronts emitted by natural or artificial guided stars are measured via wavefront sensors and, subsequently, corrected using deformable mirrors (DM’s).
Additionally, several AO systems require the reconstruction of the turbulence profiles in the atmosphere, which is called atmospheric tomography. Mathematically, such problems are ill-posed, i.e., the recovery from noise measurements which is done by inverting the atmospheric tomography operator. These underlying ill-posed problems have to be solved in real-time, as the atmospheric turbulences change within milliseconds. The aim of the ESR is to develop atmospheric layer model reduction methods and to collaborate in the development and adaption of reconstruction algorithms. Finally, the algorithms have to be optimized and implemented in the Real Time Computing and DM hardware of the industrial partner Microgate.
Atmospheric turbulence from the telescope’s opening. The different colors correspond to the deformation of the incoming light waves. Credits: ESO
The future ELT centering the 40-metre-class primary mirror which will consist of almost 800 hexagonal segments, each 1.4 metres wide, but only 50 mm thick. Credits: ESO