Modal tomography for adaptive optics

Abstract

Multiple Laser Guide Stars can be used to retrieve the three-dimensional distribution of the perturbing layers on the coming wavefront in Adaptive Optics system and to derive corrections for conical anisoplanatism. We outline the basic an- alytical details of a modal approach to this problem. The ad- vantages of this approach with respect to the traditional zonal one are pointed out along with a preliminary discussion of the way the involved matrices are to be treated in order to minimize noise propagation problems.