I am working as contractor for the U.S. Naval Observatory at the Naval Prototype Optical Interferometer.
The NPOI is a specialized astronomical telescope called an interferometer. Instead of a single telescope,
an array of six mirrors spaced tens of meters apart precisely direct beams of light from a star to a point.
Extraordinary image detail can be derived from the resulting data.
NPOI can record images of stars and optically separate distant pairs of stars so close together that
they appear as a single star in even the largest conventional telescopes.
The NPOI has the ability to measure
the precise relative positions of stars across the sky which the Naval Observatory uses as a reference system
for the determination of
positions on earth and in space and for monitoring time keeping. Currently operating
at about one-fourth of its designed capability, when finished the interferometer will span
the distance of
over four football field lengths, 430 meters.
[See NPOI Website]