Translator Disclaimer
18 August 2005 APE: the Active Phasing Experiment to test new control system and phasing technology for a European Extremely Large Optical Telescope
Author Affiliations +
The future European Extremely Large Telescope will be composed of one or two giant segmented mirrors (up to 100 m of diameter) and of several large monolithic mirrors (up to 8 m in diameter). To limit the aberrations due to misalignments and defective surface quality it is necessary to have a proper active optics system. This active optics system must include a phasing system to limit the degradation of the PSF due to misphasing of the segmented mirrors. We will present the lastest design and development of the Active Phasing Experiment that will be tested in laboratory and on-sky connected to a VLT at Paranal in Chile. It includes an active segmented mirror, a static piston plate to simulate a secondary segmented mirror and of four phasing wavefront sensors to measure the piston, tip and tilt of the segments and the aberrations of the VLT. The four phasing sensors are the Diffraction Image Phase Sensing Instrument developed by Instituto de Astrofisica de Canarias, the Pyramid Phasing Sensor developed by Arcetri Astrophysical Observatory, the Shack-Hartmann Phasing Sensor developed by the European Southern Observatory and the Zernike Unit for Segment phasing developed by Laboratoire d'Astrophysique de Marseille. A reference measurement of the segmented mirror is made by an internal metrology developed by Fogale Nanotech. The control system of Active Phasing Experiment will perform the phasing of the segments, the guiding of the VLT and the active optics of the VLT. These activities are included in the Framework Programme 6 of the European Union.
© (2005) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
F. Gonte, N. Yaitskova, F. Derie, C. Araujo, R. Brast, B. Buzzoni, B. Delabre, P. Dierickx, C. Dupuy, R. Esteves, C. Frank, S. Guisard, R. Karban, E. Koenig, J. Kolb, M. Nylund, L. Noethe, I. Surdej, A. Courteville, R. Wilhelm, L. Montoya, M. Reyes, S. Esposito, E. Pinna, K. Dohlen, M. Ferrari, and M. Langlois "APE: the Active Phasing Experiment to test new control system and phasing technology for a European Extremely Large Optical Telescope", Proc. SPIE 5894, Advanced Wavefront Control: Methods, Devices, and Applications III, 58940Z (18 August 2005);


Active control of the Chinese Giant Solar Telescope
Proceedings of SPIE (July 21 2014)
A primary mirror metrology system for the GMT
Proceedings of SPIE (July 26 2016)
APE a breadboard to evaluate new phasing technologies for...
Proceedings of SPIE (September 27 2004)
Field stabilization on the ESO VLT telescopes
Proceedings of SPIE (June 15 2000)

Back to Top