Abstract

An experiment is being performed at LMSC to characterize the performance of a device designed to maintain to high precision the relative alignment of large-aperture optical telescopes separated by large distances. The two-body relative attitude control system (TRACS) measures and controls relative angular motions between two V-shaped Zerodur mirrors separated by 2 m. The design eliminates first-order errors due to the instability of the laser and small amplitude motions in the optical components, making it possible to measure all three relative tilts to within a microradian. This is accomplished by directly comparing the beam which samples the orientation of the Zerodur mirrors to a reference beam which carries common path errors. The measurements are derived from quadrant detector outputs which feed back through a control loop to three pizoelectric actuators that control the tilts of one Zero-dur mirror.

© 1989 Optical Society of America