A&AS Supplement Series, Vol. 125, November I 1997, 581-593

Received September 12, 1996; accepted February 12, 1997

Image quality with current adaptive optics instruments

E. Tessier

Royal Greenwich Observatory, Madingley road, Cambridge CB3 0EZ, UK
e-mail address: tessier@ast.cam.ac.uk

Abstract:

From natural guide star adaptive optics data, we study the properties of the on-axis point spread function and discuss the performance of adaptive optics images. A close relation between the full width half maximum and the Strehl ratio is shown. The ultimate exploitation of adaptive optics images requires the deconvolution and therefore the calibration of the point spread function. This calibration is commonly made by sequentially observing a point source close to the astronomical target. In the partial correction regime, the calibration mismatch is the main source of noise or bias in the deconvolution process and it is mainly induced by the varying seeing conditions. Complementary techniques like near-sighted deconvolution, speckle and rebinning are briefly reviewed.

keywords: atmospheric effects -- instrumentation: miscellaneous -- methods: data analysis; observational -- techniques: interferometric; image processing

• 1. Introduction
• 2. Instruments and data
• 3. Psf characteristics
• 4. Calibration of AO images
• 5. Performance
• 6. Deconvolution of AO images
• 7. Speckle with adaptives optics
• 8. Conclusion
• A. Strehl ratio computation
• B. Image processing software
• References