{'fraction_non_alphanumeric': 0.0189873417721519, 'fraction_numerical': 0.006329113924050633, 'mean_word_length': 4.859259259259259, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
3D mapping of turbulence: theory

In this paper we study a multi-conjugate adaptive optics system which has 4 laser guide stars and 2 deformable mirrors. An interaction matrix describing the whole system is computed, and its eigenmodes are analyzed. The implication of the inability to measure tilt from the artificial guide stars are investigated. We show that a single natural guide star anywhere in the corrected FOV is sufficient to correct the singular modes, provided 5 modes are measured from that guide star. These modes are tilts, defocus and astigmatisms. The performance of this AO system are estimated, taking into account only fitting, aliasing and matrix inversion errors. It is shown that good correction performances are obtained in the visible, with an 8 m class telescope.