Abstract

A wide-angle unobscured mirror system is described which has a flat focal plane and a distant external real pupil out in front. The system acts as a collimator for an infrared target that is placed in the focal plane. Its external pupil is then matched to the pupils (usually interior to them) of test devices, e.g., infrared tracking systems, seeker heads. The system has been built with an 8-in. unobscured aperture and has a measured spot size of 0.05 mrad (10 arc sec) over most of the flat 8 × 8° square field of view. Several interesting design principles were used, which are explained, which allowed the design to consist of one centered conic mirror and several spherical mirrors.

© 1988 Optical Society of America