Bibcode
Le Louarn, M.; Tallon, M.; Sánchez-Capuchino, J.; Béchet, C.; Montilla, I.; Collados Vera, M.
Referencia bibliográfica
Adaptive Optics Systems III. Proceedings of the SPIE, Volume 8447, id. 84475H-84475H-7 (2012).
Fecha de publicación:
7
2012
Número de citas
1
Número de citas referidas
0
Descripción
The European Solar Telescope (EST) will be a 4-meter diameter
world-class facility, optimized for studies of the magnetic coupling
between the deep photosphere and upper chromosphere. It will specialize
in high spatial resolution observations and therefore it has been
designed to incorporate an innovative built-in Multi-Conjugate Adaptive
Optics system (MCAO). It combines a narrow field high order sensor that
will provide the information to correct the ground layer and a wide
field low order sensor for the high altitude mirrors used in the MCAO
mode. One of the challenging particularities of solar AO is that it has
to be able to correct the turbulence for a wide range of observing
elevations, from zenith to almost horizon. Also, seeing is usually worse
at day-time, and most science is done at visible wavelengths. Therefore,
the system has to include a large number of high altitude deformable
mirrors. In the case of the EST, an arrangement of 4 high altitude DMs
is used. Controlling such a number of mirrors makes it necessary to use
fast reconstruction algorithms to deal with such large amount of degrees
of freedom. For this reason, we have studied the performance of the
Fractal Iterative Method (FriM) and the Fourier Transform Reconstructor
(FTR), to the EST MCAO case. Using OCTOPUS, the end-to-end simulator of
the European Southern Observatory, we have performed several simulations
with both algorithms, being able to reach the science requirement of a
homogeneous Strehl higher that 50% all over the 1 arcmin field of view.