Phase estimation for large field of view: application to multiconjugate adaptive optics

We propose a `Maximum A Posteriori-based' estimation of the turbulent phase in a large field of view (FOV) to overcome the anisoplanatism limitation in adaptive optics. We show that, whatever the true atmospheric profile, a small number of equivalent layers (2 or 3) is required to obtain an accurate restitution of the phase in the whole FOV. The implications on multiconjugate adaptive optics are discussed in terms of number and conjugated heights of the deformable mirrors. The number of guide stars for the wavefront measurements in the field is also discussed: 3 (or even 2) guide stars are sufficient to obtain good performance.

[1]  Nicolas A. Roddier.  Atmospheric wavefront simulation using Zernike polynomials , 1990 .

[2]  R. Noll.  Zernike polynomials and atmospheric turbulence , 1976 .

[3]  Jérôme Primot,et al.  Deconvolution from wave-front sensing: a new technique for compensating turbulence-degraded images , 1990 .

[4]  Francois Rigaut,et al.  Laser guide star in adaptive optics : the tilt determination problem , 1992 .

[5]  Brent L. Ellerbroek,et al.  Profiles of nighttime turbulence above Mauna Kea and isoplanatism extension in adaptive optics , 1995, Optics & Photonics.

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

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

[8]  T. Fusco,et al.  Myopic deconvolution method for adaptive optics images of stellar fields , 1999 .

[9]  L M Mugnier,et al.  Myopic deconvolution of adaptive optics images by use of object and point-spread function power spectra. , 1998, Applied optics.

[10]  Gerard Rousset,et al.  Deconvolution from wavefront sensing. , 1987 .

[11]  R G Paxman,et al.  Phase-diversity correction of turbulence-induced space-variant blur. , 1994, Optics letters.

[12]  Franck Marchis,et al.  Myopic deconvolution of Adaptive Optics Images , 1999 .

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

[14]  R. Foy,et al.  Adaptive telescope with laser probe : isoplanatism and cone effect , 1990 .

[15]  Byron M. Welsh,et al.  Analysis of Multiconjugate Adaptive Optics , 1992, Adaptive Optics for Large Telescopes.

[16]  Michel Tallon,et al.  Focusing on a Turbulent Layer: Principle of the “Generalized SCIDAR” , 1998 .