Optimum synthetic-aperture imaging of extended astronomical objects

In optical aperture-synthesis imaging of stellar objects, different beam combination strategies are used and proposed. Coaxial Michelson interferometers are very common and a homothetic multiaxial interferometer is recently realized in the Large Binocular Telescope. Laboratory experiments have demonstrated the working principles of two new...

Optical aperture synthesis: A comparison of techniques for wide-field interferometric imaging

The research described in this thesis provides onsets for research in several areas of interest related to aperture synthesis and guidelines concerning the design of synthetic telescopes for imaging. As such, this research contributes to the improvement of instrumentation for observational astronomy, in particular for stellar interferometry....

Comparison of blind imaging performance of Fizeau and Michelson type arrays for a partially resolved object

This paper compares two well-known types of interferometer arrays for optical aperture synthesis. An analytical model for both types describes the expected output, in terms of photon counts. The goal is to characterize the performance of both types of array for blind imaging of a wide-field or extended object that would be partially resolved by...

Homothetic mapping as means to obtain a wide field of view: The Delft Testbed Interferometer

The Delft Testbed Interferometer (DTI) will be presented. The basics of homothetic mapping will be explained together with the method of fulfilling the requirements as chosen in the DTI setup. The optical layout incorporates a novel tracking concept enabling the use of homothetic mapping in real telescope systems for observations on the sky. The...

Demonstration of nulling using delay line phase shifters

We present results of experiments obtained using a new nulling technique that enables deep nulling without the use of achromatic phase shifters. The experimental set-up consists of a three-beam interferometer that should provide a nulling depth of several thousands over a wavelength range of 500 to 650 nm. The intended depth of null was not...

Experimental performance of homothetic mapping for wide field interferometric imaging

Homothetic mapping is an aperture synthesis technique that allows interferometric imaging over a wide fieldof-view. A laboratory experiment was set up to demonstrate the feasibility of this technique. Here, we present the first static experiments on homothetic mapping that have been done on the Delft Testbed for Interferometry (DTI). Before a...

Delft Testbed Interferometer: Homothetic mapping and astrometric performances

A special case of optical aperture synthesis, homothetic mapping, is the topic of this paper. It allows for a wide field of view for interferometric instruments, interesting for astrometric measurments of wide objects. This paper describes a testbed constructed and tested in TNO-TPD in Delft (the Netherlands). This testbed is intended as a tool...

Mechanical setup for optical aperture synthesis for wide field imaging

Homothetic mapping is a technique that combines the images from several telescopes so that it looks like as though they came form a single large telescope. This technique enables a much wider interferometric field of image than current techniques can provide. To investigate the feasibility, a research testbed is build know as Delft Testbed...