Simulation of wavefront measurement and tomography for Extremely Large Telescope

The control of AO systems dedicated to ELT is a difficult problem related to the large number of degrees of freedom. The standard and most used adaptive optics AO control starting from the integrator to the LQG are not useful in such a case. In fact, for future Extremely Large Telescope (ELT's) the number of degrees of freedom is very large related to the large diameter of the ELT's and the emergence of new architectures for the AO systems. So that the necessary computational power for real time control RTC on such systems is currently unattainable when using these control methods. In this paper we present an Adaptive Optics E2E simulator which includes a very fast wave front reconstruction which is dedicated for the Extremely Large Telescope. This code takes advantages of the SOY library, where we build the interaction and reconstruction matrix in a sparse format. Based on a script for solving linear systems by conjugate gradient with Jacobi preconditioner , our reconstruction matrix is computed very fast. Moreover, we present the reconstruction results for a 42 m and so the characterization time of the code.