Optical propagation through atmospheric turbulence. Model analysis of anisoplanatism and application to adaptive optics
Abstract
The correction capability of adaptive optics techniques is discussed. The correction capability of these techniques is limited by: no amplitude correction, difference between the sensing, the correcting wavelengths, and anisoplanatism effect. A theoretical analysis of this phenomenon is performed, considering the modal expansion of the wavefronts on the Zernike polynomials. The spatial correlation of the modal expansion coefficients is derived. The results can be used: to characterize the performance of an adaptive optics system against anisoplanatism; to optimize this performance by tuning up the number of corrected modes; to limit the loss of correction quality due to anisoplanatism by feedback into the correction process. The possibility of working back from the wavefront measurements on a binary star to the profile of the refractive index fluctuations constant is explained. The experiments carried out to investigate the anisoplanatism effects and to validate the theory are presented.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- November 1992
- Bibcode:
- 1992PhDT........31C
- Keywords:
-
- Adaptive Optics;
- Atmospheric Turbulence;
- Light Transmission;
- Reference Stars;
- Space Observations (From Earth);
- Spatial Resolution;
- Imaging Techniques;
- Refractivity;
- Telescopes;
- Wave Front Reconstruction;
- Geophysics