Astron. Astrophys. Suppl. Ser. 141, 301-311

Interferometric imaging tests for the Large Binocular Telescope

S. Correia - A. Richichi

Send offprint request: S. Correia
e-mail: correia@arcetri.astro.it

Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze, Italy

Received July 5; accepted August 15, 1999

Abstract:

We present an experiment of interferometric imaging for the Large Binocular Telescope (LBT), conducted at the 1.5m TIRGO infrared telescope. The raw data were produced by simulating the LBT pupil with a mask on the secondary mirror. Two different conditions of D/r₀, where D is the single aperture diameter and r₀ the Fried parameter, were simulated by the choice of D; field rotation was simulated by rotating the mask. The data set collected consists of several sequences of short exposure interferograms of one point-like and one binary star in the J-band, for two different D/r₀ conditions. We show preliminary results, in particular concerning the fringe contrast loss with integration time. The ability of a Lucy-Richardson-based deconvolution algorithm to reconstruct an object from a set of LBT-like interferometric real data was demonstrated on the binary star $\gamma$Leo. The retrieved binary parameter values are compared to catalog values, and a good astrometric agreement is found. Photometric and resolution limitations are also discussed. In a first part, the reconstruction method and preliminary numerical simulations of LBT image restoration using this method are presented.

Key words: instrumentation: interferometers -- methods: data analysis -- techniques: image processing -- techniques: interferometric -- telescopes -- stars: imaging