DIPSI: measure of the tip-tilt with a diffraction image phase sensing instrument

Chueca, Sergio; Reyes, Marcos; Schumacher, Achim; Montoya, Luzma
Bibliographical reference

Ground-based and Airborne Telescopes II. Edited by Stepp, Larry M.; Gilmozzi, Roberto. Proceedings of the SPIE, Volume 7012, pp. 701213-701213-11 (2008).

Advertised on:
8
2008
Number of authors
4
IAC number of authors
3
Citations
0
Refereed citations
0
Description
Large segmented mirrors require efficient co-phasing techniques in order to avoid the image degradation due to segments misalignment. DIPSI (Diffraction Image Phase Sensing Instrument) is an instrument developed by IAC, GRANTECAN and LAM. This instrument is being integrated in the Active Phasing Experiment (APE), aimed at testing different phasing techniques for an Extremely Large Telescope. This paper describes the mathematical solution for determining piston and tip-tilt simultaneously from the DIPSI images. A complete set of simulations is included to study the residual errors. Residual errors are bigger when piston and tip-tilt are combined (three degrees of freedom).