Synthetic-aperture imaging with the European Very Large Telescope

Abstract

The European Southern Observatory Very Large Telescope is a project for a linear array of four independent 8-m telescopes. This concept offers the possibility of operating the telescopes in the synthetic-aperture mode as an interferometer with a maximum baseline of approximately 112 m. The first target for the interferometric operation is phasing in the infrared range, with a gradual expansion toward shorter wavelengths. Two smaller movable telescopes are added to the linear array for a complete filling of the spatial-frequency plane. Adaptive optics is applied for a real-time phase compensation of the individual pupils for atmospheric distortions. The whole array, in addition to the individual pupils of the independently mounted telescopes, must be phased, including pupil position corrections due to pupil foreshortening and shift effects, in order to reach a reasonable phased field of view.