EDP Sciences
Free access
Volume 382, Number 2, February I 2002
Page(s) 746 - 751
Section Instruments, observational techniques and data processing
DOI http://dx.doi.org/10.1051/0004-6361:20011635

A&A 382, 746-751 (2002)
DOI: 10.1051/0004-6361:20011635

Co-phasing of segmented telescopes: A new approach to piston measurements

I. Optical concept
V. V. Voitsekhovich1, S. Bara2 and V. G. Orlov1

1  Instituto de Astronomia, UNAM AP 70-264 Cd. Universitaria, 04510 Mexico DF, Mexico
2  Area de Optica, Departamento de Fisica Aplicada, Facultade de Fisica, Universidade de Santiago de Compostela, Campus Sur, 15706 Santiago de Compostela, Galicia, Spain
    e-mail: fagosxbv@usc.es

(Received 23 July 2001 / Accepted 2 October 2001 )

One of the main problems arising in the co-phasing of segmented telescopes is the problem of measurements of the relative pistons among the segments. These measurements become especially complicated when the pistons are in order of wavelength fractions. In this paper we present a new approach relative piston measurements which allows for a high-accuracy reconstruction of small pistons. Our approach is based on the shearing interferometry and compared to existed methods it has the following advantages: a high accuracy of piston reconstruction in presence of high levels of noise is combined with the ability to retrieve the pistons taking into account the segment's aberrations.

Key words: instrumentation: miscellaneous -- techniques: miscellaneous

Offprint request: V. V. Voitsekhovich, voisteko@astroscu.unam.mx

© ESO 2002