Open loop tomography with artificial neural networks on CANARY: on-sky results

Osborn, J.; Guzman, D.; De Cos Juez, F.J.; Basden, A.G.; Morris, T.J.; Gendron, E.; Butterley, T.; Myers, R.M.; Guesalaga, A.; Sanchez Lasheras, F.; Gomez Victoria, M.; Sánchez Rodríguez, M.L.; Gratadour, D.; Rousset, G.

Abstract

We present recent results from the initial testing of an artificial neural network (ANN)-based tomographic reconstructor Complex Atmospheric Reconstructor based on Machine lEarNing (CARMEN) on CANARY, an adaptive optics demonstrator operated on the 4.2 m William Herschel Telescope, La Palma. The reconstructor was compared with contemporaneous data using the Learn and Apply (L&A) tomographic reconstructor. We find that the fully optimized L&A tomographic reconstructor outperforms CARMEN by approximately 5 per cent in Strehl ratio or 15 nm rms in wavefront error. We also present results for CANARY in Ground Layer Adaptive Optics mode to show that the reconstructors are tomographic. The results are comparable and this small deficit is attributed to limitations in the training data used to build the ANN. Laboratory bench tests show that the ANN can outperform L&A under certain conditions, e.g. if the higher layer of a model two layer atmosphere was to change in altitude by ∼300 m (equivalent to a shift of approximately one tenth of a subaperture).

Citation

Osborn, J., Guzman, D., De Cos Juez, F., Basden, A., Morris, T., Gendron, E., …Rousset, G. (2014). Open loop tomography with artificial neural networks on CANARY: on-sky results. Monthly Notices of the Royal Astronomical Society, 441(3), 2508-2514. https://doi.org/10.1093/mnras/stu758

• Journal Article Type: Article
• Acceptance Date: Apr 12, 2014
• Online Publication Date: May 20, 2014
• Publication Date: Jul 1, 2014
• Deposit Date: Nov 24, 2014
• Publicly Available Date: Apr 28, 2015
• 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: 441
• Issue: 3
• Pages: 2508-2514
• DOI: https://doi.org/10.1093/mnras/stu758
• Keywords: Atmospheric effects, Instrumentation: adaptive optics.
• Public URL: https://durham-repository.worktribe.com/output/1417154