OPERA, an automatic PSF reconstruction software for Shack-Hartmann AO systems: Application to Altair

Document Type

Conference Proceeding

Publication Date

12-1-2004

Abstract

When doing high angular resolution imaging with adaptive optics (AO), it is of crucial importance to have an accurate knowledge of the point spread function associated with each observation, Applications are numerous: image contrast enhancement by deconvolution, improved photometry and astrometry, as well as real time AO performance evaluation. In this paper, we present our work on automatic PSF reconstruction based on control loop data, acquired simultaneously with the observation. This problem has already been solved for curvature AO systems. To adapt this method to another type of WFS, a specific analytical noise propagation model must be established. For the Shack-Hartmann WFS, we are able to derive a very accurate estimate of the noise on each slope measurement, based on the covariances of the WFS CCD pixel values in the corresponding sub-aperture. These covariances can be either derived off-line from telemetry data, or calculated by the AO computer during the acquisition. We present improved methods to determine 1) r0 from the DM drive commands, which includes an estimation of the outer scale L0; 2) the contribution of the high spatial frequency component of the turbulent phase, which is not corrected by the AO system and is scaled by r0. This new method has been implemented in an IDL-based software called OPERA (Performance of Adaptive Optics). We have tested OPERA on Altair, the recently commissioned Gemini-North AO system, and present our preliminary results. We also summarize the AO data required to run OPERA on any other AO system.

Identifier

11144314664 (Scopus)

Publication Title

Proceedings of SPIE the International Society for Optical Engineering

External Full Text Location

https://doi.org/10.1117/12.551767

ISSN

0277786X

First Page

151

Last Page

163

Issue

PART 1

Volume

5490

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