Patent ID: 8203702

Claim:
An optical system dynamically determining associated angular direction throughout a specified range of angular directions, of an external article in a volume outside the system; said optical system comprising: a radiation source; an optical detector; an entrance aperture; an afocal element, associated with the aperture, enlarging the field of regard of such external article and such volume as seen by the source and detector; disposed along an optical path between (1) selectively, the source or detector and (2) the entrance aperture: at least one mirror rotatable about plural axes and causing the source and detector to address varying portions of such volume outside the optical system; and each mirror of the at least one mirror having dimensions in a range exceeding five millimeters; wherein, due to said enlarging of the field of regard together with rotation of the at least one mirror, and substantially without changing magnitude of said enlarging, such external article receives radiation from the source and returns said radiation to the detector throughout the specified range; and wherein the aperture, afocal element, and at least one mirror together form a common optical path for said radiation from the source and to the detector.