Optimal control law for multiconjugate adaptive optics

We propose in this paper an optimal closed loop control law for multiconjugate adaptive optics (MCAO), based on a Kalman filter and a feedback control. The so-called open loop optimal phase reconstruction is recalled. It is based on a Maximum A Posteriori (MAP) approach. This approach takes into account wavefront sensing noise and also makes use of a turbulence profile model and Kolmogorov statistics. We propose a closed-loop modelization via a state-space representation. A Kalman filter is used for the phase reconstruction. This approach is a closed loop generalization of the MAP open loop estimator. It uses the same spatial prior in addition with a temporal model of the turbulence. Results are compared with the Optimized Modal Gain Integrator approach in the classical adaptive optics case and in an MCAO-like case.

[1]  Laurent M. Mugnier,et al.  Isoplanatic angle and optimal guide star separation for multiconjugate adaptive optics , 2000, Astronomical Telescopes and Instrumentation.

[2]  Aaas News,et al.  Book Reviews , 1893, Buffalo Medical and Surgical Journal.

[3]  J. Conan,et al.  Wave-front temporal spectra in high-resolution imaging through turbulence , 1995 .

[4]  Miska Le Louarn.  Etoiles laser pour les grands telescopes: effet de cone et implications astrophysiques , 2000 .

[5]  B. Ellerbroek.  First-order performance evaluation of adaptive optics systems for atmospheric turbulence compensatio , 1994 .

[6]  E. Marchetti,et al.  Modal tomography for adaptive optics , 1999 .

[7]  Jacques M. Beckers,et al.  Increasing the size of the isoplanatic patch with multiconjugate adaptive optics. , 1988 .

[8]  R. Ragazzoni,et al.  No Laser Guide Stars for adaptive optics in giant telescopes , 1999 .

[9]  Eric Gendron.  Optimisation de la commande modale en optique adaptative : applications à l'astronomie , 1995 .

[10]  R. Stephenson.  A and V , 1962, The British journal of ophthalmology.

[11]  L M Mugnier,et al.  Optimal wave-front reconstruction strategies for multiconjugate adaptive optics. , 2001, Journal of the Optical Society of America. A, Optics, image science, and vision.

[12]  Gerard Rousset,et al.  Status of the VLT Nasmyth adaptive optics system (NAOS) , 2000, Astronomical Telescopes and Instrumentation.

[13]  Thierry Fusco,et al.  Correction partielle et anisoplanétisme en optique adaptative : traitements a posteriori et optique adaptative multiconjuguée , 2000 .

[14]  G Rousset,et al.  Optimization of a predictive controller for closed-loop adaptive optics. , 1998, Applied optics.

[15]  Caroline Dessenne,et al.  Commande modale et predictive en optique adaptative , 1998 .

[16]  J. Conan,et al.  Efficient phase estimation for large-field-of-view adaptive optics. , 1999, Optics letters.

[17]  Robert H. Dicke,et al.  Phase-contrast detection of telescope seeing errors and their correction. , 1975 .