On-sky demonstration of matched filters for wavefront measurements using ELT-scale elongated laser guide stars

Basden, A.G.; Bardou, L.; Bonaccini-Calia, D.; Buey, T.; Centrone, M.; Chemla, F.; Gach, J.L.; Gendron, E.; Gratadour, D.; Guidolin, I.; Jenkins, D.R.; Marchetti, E.; Morris, T.J.; Myers, R.M.; Osborn, J.; Reeves, A.P.; Reyes, M.; Rousset, G.; Stangalini, M.; Townson, M.J.; Vidal, F.

Abstract

The performance of adaptive optics systems is partially dependent on the algorithms used within the real-time control system to compute wavefront slope measurements. We demonstrate the use of a matched filter algorithm for the processing of elongated laser guide star (LGS) Shack–Hartmann images, using the CANARY adaptive optics instrument on the 4.2 m William Herschel Telescope and the European Southern Observatory Wendelstein LGS Unit placed 40 m away. This algorithm has been selected for use with the forthcoming Thirty Meter Telescope, but until now had not been demonstrated on-sky. From the results of a first observing run, we show that the use of matched filtering improves our adaptive optics system performance, with increases in on-sky H-band Strehl measured up to about a factor of 1.1 with respect to a conventional centre of gravity approach. We describe the algorithm used, and the methods that we implemented to enable on-sky demonstration.

Citation

Basden, A., Bardou, L., Bonaccini-Calia, D., Buey, T., Centrone, M., Chemla, F., …Vidal, F. (2017). On-sky demonstration of matched filters for wavefront measurements using ELT-scale elongated laser guide stars. Monthly Notices of the Royal Astronomical Society, 466(4), 5003-5010. https://doi.org/10.1093/mnras/stx062

• Journal Article Type: Article
• Acceptance Date: Jan 9, 2017
• Online Publication Date: Jan 12, 2017
• Publication Date: May 1, 2017
• Deposit Date: Mar 13, 2017
• Publicly Available Date: Mar 16, 2017
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Royal Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 466
• Issue: 4
• Pages: 5003-5010
• DOI: https://doi.org/10.1093/mnras/stx062
• Public URL: https://durham-repository.worktribe.com/output/1362170
• Related Public URLs: https://arxiv.org/abs/1702.03736