Layer-oriented multigrid wavefront reconstruction algorithms for multiconjugate adaptive optics

Luc Gilles, Brent L. Ellerbroek, Curtis R. Vogel, Peter L. Wizinowich, Domenico Bonaccini
2003 Adaptive Optical System Technologies II  
Multi-conjugate adaptive optics (MCAO) systems with 10 4 − 10 5 degrees of freedom have been proposed for future giant telescopes. Using standard matrix methods to compute, optimize, and implement wavefront control algorithms for these systems is impractical, since the number of calculations required to compute and apply the reconstruction matrix scales respectively with the cube and the square of the number of AO degrees of freedom. In this paper, we develop an iterative sparse matrix
more » ... ation of minimum variance wavefront reconstruction for telescope diameters up to 32m with more than 10 4 actuators. The basic approach is the preconditioned conjugate gradient method, using a multigrid preconditioner incorporating a layer-oriented (block) symmetric Gauss-Seidel iterative smoothing operator. We present open-loop numerical simulation results to illustrate algorithm convergence.
doi:10.1117/12.459347 fatcat:62p2yqkqzffqvehu73543rygom