Sensitivity of a “dispersed-speckles” piston sensor for multi-aperture interferometers and hypertelescopes
Collège de France & Laboratoire d'Interférométrie Stellaire et Exo-planétaire LISE-Observatoire de Haute-Provence - CNRS, 04870 Saint-Michel l'Observatoire, France e-mail: firstname.lastname@example.org
2 Alcatel Space Industries, 100 bd du Midi, BP 99, 06156 Cannes la Bocca Cedex, France
3 Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794-3800, USA
Accepted: 2 September 2004
In multi-aperture interferometers and hypertelescopes, the piston errors can be determined from multi-spectral images of the speckle pattern using a 3-dimensional Fourier transform. We study the limiting magnitude of the method in the case of non-redundant apertures using analytical derivations and numerical simulations. We show specifically for the case of sub-r0 apertures that a few photons per aperture within the full spectral bandwidth will suffice to measure piston errors. The method's sensitivity is thus comparable to that of the Shack-Hartmann and other methods used with monolithic apertures.
Key words: turbulence / techniques: interferometric / atmospheric effects
© ESO, 2005