English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We present the results obtained with an end-to-end simulator of an ExtremeAdaptive Optics (XAO) system control loop. It is used to predict its on-skyperformances and to optimise the AO loop algorithms. It was first used tovalidate a novel analytical model of the fitting error, a limit due to theDeformable Mirror (DM) shape. Standard analytical models assume a sharpcorrection under the DM cutoff frequency, disregarding the transition betweenthe AO corrected and turbulence dominated domains. Our model account for theinfluence function shape in this smooth transition. Then, it is well-known thatShack-Hartmann wavefront sensors (SH-WFS) have a limited spatial bandwidth, thehigh frequencies of the wavefront being seen as low frequencies. We show thatthis aliasing error can be partially compensated (both in terms of Strehl ratioand contrast) by adding priors on the turbulence statistics in the framework ofan inverse problem approach. This represents an alternative to the standardadditional optical filter used in XAO systems. In parallel to this numericalwork, a bench was aligned to experimentally test the AO system and these newalgorithms comprising a DM192 ALPAO deformable mirror and a 15x15 SH-WFS. Wepresent the predicted performances of the AO loop based on end-to-endsimulations.

Inverse problem approach in Extreme Adaptive Optics: analytical model of the fitting error and lowering of the aliasing