  The U.S. Naval Observatory Robotic Astrometric Telescope (URAT) project aims
at a highly accurate (5 mas), ground-based, all-sky survey. Requirements are
presented for the optics and telescope for this 0.85 m aperture, 4.5 degree
diameter field-of-view, specialized instrument, which are close to the
capability of the industry. The history of the design process is presented as
well as astrometric performance evaluations of the toleranced, optical design,
with expected wavefront errors included.
