Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A tomographic algorithm to determine tip-tilt information from laser
  guide stars   Laser Guide Stars (LGS) have greatly increased the sky-coverage of Adaptive
Optics (AO) systems. Due to the up-link turbulence experienced by LGSs, a
Natural Guide Star (NGS) is still required, preventing full sky-coverage. We
present a method of obtaining partial tip-tilt information from LGSs alone in
multi-LGS tomographic LGS AO systems. The method of LGS up-link tip-tilt
determination is derived using a geometric approach, then an alteration to the
Learn and Apply algorithm for tomographic AO is made to accommodate up-link
tip-tilt. Simulation results are presented, verifying that the technique shows
good performance in correcting high altitude tip-tilt, but not that from low
altitudes. We suggest that the method is combined with multiple far off-axis
tip-tilt NGSs to provide gains in performance and sky-coverage over current
tomographic AO systems.

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The categories of this paper are: comp-gas
19
The categories of this paper are: eess
24
The categories of this paper are: dg-ga
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs
14
The categories of this paper are: math-ph
35
The categories of this paper are: mtrl-th
13
The categories of this paper are: quant-ph
26
The categories of this paper are: bayes-an
33
The categories of this paper are: plasm-ph
22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ