The impact of ELT distortions and instabilities on future astrometric observations

The paper discusses an assessment study about the impact of the distortions on the astrometric observations with the Extremely Large Telescope originated from the optics positioning errors and telescope instabilities. Optical simulations combined with Monte Carlo approach reproducing typical inferred opto-mechanical and dynamical instabilities show rms distortions between ∼0.1 and 5 mas over 1 arc...