Wide angle projection system

TLDR: A projection system that is particularly suited for simulating aircraft flight includes a large dome and a projector and optical system that are located outside of the dome as mentioned in this paper, which produces a pattern of light which is redirected by the optical system such that it passes through an aperture in the dome, and is cast upon a wide area of the diffuse reflective surface as an image of a scene.

Abstract: A projection system that is particularly suited for simulating aircraft flight includes a large dome and a projector and optical system that are located outside of the dome. The dome has a diffuse reflective surface that is presented inwardly. The projector produces a pattern of light which is redirected by the optical system such that it passes through an aperture in the dome, and is cast upon a wide area of the diffuse reflective surface as an image of a scene, particularly a scene that one might encounter from the cockpit of an aircraft. The optical system includes a concave mirror that is presented toward the aperture, a wide angle lens that is along the axis of the mirror, and a system of lens and folding mirrors for transmitting the light from the projector to the wide angle lens. The wide angle lens is located such that its pupil upon being reflected from the concave mirror reforms or comes into focus at the aperture in the dome. Thus, the light upon diverging from the wide angle lens reflects from the concave mirror and concentrates at the aperture through which it passes, diverging beyond the aperture to come into focus on the diffuse reflective surface, where it forms an image of the scene developed at the projector.