A&A Supplement series, Vol. 128, February II 1998, 229-244

Received March 13; accepted July 1, 1997

Performance analysis for T.H.E.M.I.S(*) image stabilizer optical system

II. Anisoplanatism limitations
(*)Télescope Héliographique pour l'Etude du Magnétisme et des Instabilités de l'atmosphère Solaire

G. Molodij and J. Rayrole

Observatoire de Paris URA 326, CNRS, 61 Av. de l'Observatoire, 75014 Paris, France

Abstract:

Numerical simulations of anisoplanatism effects after compensation by the T.H.E.M.I.S. image stabilizer optical system when observing extended sources are presented. The residual wavefront error after correction is computed using the expansion on the Zernike polynomials to analyze the performances of different adaptive optics systems for solar observations. The long exposure optical tranfer functions are derived to simulate the image quality after correction for extended field of view. We demonstrate the capacity of the image stabilizer system for very large field of view observations with medium image quality while the capacity of high order adaptive optics system is suitable for high image quality observations but to the price of a reduction of the field of view.

keywords: telescopes -- atmospheric effects --
techniques: miscellaneous -- Sun: granulation

• 1. Introduction
• 2. Residual wavefront error
• 3. Problem of wavefront slope measurement
• 4. Computation results
• 5. Optical transfer functions
• 6. Conclusion
• A. Appendix
• References