Issue |
2010
|
|
---|---|---|
Article Number | 05018 | |
Number of page(s) | 6 | |
Section | Wave front sensing | |
DOI | https://doi.org/10.1051/ao4elt/201005018 | |
Published online | 24 February 2010 |
Focal-plane wavefront sensing for segmented telescope
1
ONERA-DOTA, Unité HRA, Châtillon, France
2
GEPI, Observatoire de Paris, CNRS, Université de Paris Diderot, Meudon,
France
3
Groupement d’intérêt scientifique PHASE between ONERA, Observatoire de Paris,
CNRS and Universite Diderot
a e-mail: enguerran.delavaquerie@onera.fr
To achieve the ultimate resolution of future ELTs, the segments of their primary mirror must be aligned. This paper present focal plane (FP) wavefront sensing techniques that allow to perform piston measurements between the segments. Those techniques have the advantage of using images that are the result of the interference of all the segments. This makes FP measurements capable of handling complex apertures. New developments at ONERA allow us to apply FP measurements for different applications. We present an upgrade of the usual Shack-Hartmann pairwise technique. We also show that phase diversity is able to cophase an ELT. Eventually, we show our current developments in term of analytical algorithms and our new bench, NIRTA, which is under integration at ONERA.
© Owned by the authors, published by EDP Sciences, 2010