Interferometric imaging tests for the Large Binocular Telescope

We present an experiment of interferometric imaging for the Large Binocular Telescope (LBT), conducted at the 1.5 m TIRGO infrared telescope. The raw data were produced by simulating the LET pupil with a mask on the secondary mirror. Two different conditions of D/r(0), where D is the single aperture diameter and r(0) 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 pointlike and one binary star in the J-band, for two different Dire 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 LET image restoration using this method are presented.