17 September 2011 A convenient telescope performance metric for imaging through turbulence
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Proceedings Volume 8127, Optical Modeling and Performance Predictions V; 812709 (2011); doi: 10.1117/12.896919
Event: SPIE Optical Engineering + Applications, 2011, San Diego, California, United States
This paper provides an overview of the various image quality metrics used in astronomical imaging and explains in details a new metric, the Normalized Point Source Sensitivity. It is based on the Equivalent Noise Area concept, an extension of the EE80% metric and is intuitively linked to the required science integration time. As it was proved in recent studies, the PSSN metric properly accounts for image degradation due to the spatial frequency content of a given telescope aberration and the effects of various errors can be multiplicatively combined, like those expressed in Central Intensity Ratio. Extensions of the metric for off-axis imaging and throughput degradation are presented. Wavelength and spatial frequency dependence of PSSN are discussed. While the proper calculation of the PSSN metric requires the precise knowledge of the PSF of both the optics and atmosphere, there is a straightforward approximation linking PSSN to the Zernike decomposition of the OPD. Besides the summary of various aspects of the Point Source Sensitivity, the paper provides many numerical examples derived for the Thirty Meter Telescope.
© (2011) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
George Z. Angeli, Byoung-Joon Seo, Carl Nissly, Mitchell Troy, "A convenient telescope performance metric for imaging through turbulence", Proc. SPIE 8127, Optical Modeling and Performance Predictions V, 812709 (17 September 2011); doi: 10.1117/12.896919; http://dx.doi.org/10.1117/12.896919


Point spread functions


Error analysis

Image quality

Spatial frequencies



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