  Equipped with a suitable optical relay system, telescopes employing low-cost
fixed primary mirrors could point and track while delivering high-quality
images to a fixed location. Such an optical tracking system would enable
liquid-mirror telescopes to access a large area of sky and employ infrared
detectors and adaptive optics. Such telescopes could also form the elements of
an array in which light is combined either incoherently or interferometrically.
Tracking of an extended field requires correction of all aberrations including
distortion, field curvature and tilt. A specific design is developed that
allows a 10-metre liquid-mirror telescope to track objects for as long as 30
minutes and to point as far as 4 degrees from the zenith, delivering a
distortion-free diffraction-limited image to a stationary detector,
spectrograph, or interferometric beam combiner.
