In this enlarged view the red beam from K-II long delay line and the
green beam from the K-I long delay line are folded into the fast delay
lines, again one per telescope. The fast delay lines track at sidereal
rate as they search to identically match the paths from the two telescopes.
The beams are compressed from 100 mm in diameter to 25 mm before being
folded into the beam combiner lab. The two separate star images are
imaged onto the Keck Angle Tracker (KAT) for tip/tilt correction and they
are combined onto the fringe tracker camera (FATCAT). The Interferometer
is operated from the adjacent Control Room.
Copyright 2001 California Association for Research in Astronomy