MezzoCielo: a new concept telescope capable of fisheye FOV at seeing limited resolution

Le résumé fourni par la source

MezzoCielo is a new concept of a two meter class wide field telescope capable of imaging most of the visible sky at once. Its design implements a glass sphere filled with refractive fluid that acts as a light collector. It focusses onto an hemispherical surface tiled by approximately 900 identical cameras. Each camera corrects the severe spherochromatism introduced by the sphere and has a FOV of approximately 5°. Collectively the telescope covers about 10,000 square degrees. The development foresees a 40cm prototype and an 80cm demonstrator before the final design. In this proceeding we present optical performance analysis for the 80cm demonstrator, mainly concerning the sphere properties and their influence on the telescope image quality. Uniform variations of the fluid’s refractive index have measurable effects. We face the challenge of thermal variations in particular, they will require some kind of compensator. We modelled gradients within the sphere: the pressure gradient from the fluid’s own weight does not have major consequences; the thermal gradient has strong effects, however, simply mixing the fluid should be enough. We explore the consequences of geometrical tolerances of the spherical collector and solutions to compensate them. Finally, we estimate throughput and the improvement from anti reflection coatings.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.