An optical path error suppression system was developed for a helicopter-mounted pointing and tracking system. Tests show the system can measure both static (thermal) and dynamic (vibration) angular changes of less than 5 microradians (1 arc second) between the folding mirror surfaces in the optical path line of sight. Collimated rays from a pulsed laser diode are projected along the optical path. A dichroic mirror returns the diode wavelength to a detector. The detector signals are processed into elevation and azimuth angular error components. A feedback controller converts the error signals into corrective commands to the servo-driven stabilized mirror. Tests of the system which simulated the helicopter vibration environment showed RMS line-of-sight errors were reduced from 56 µR to 7 µR, an improvement of 800%.

Date Published: 4 October 1979
PDF: 8 pages
Proc. SPIE 0187, System Aspects of Electro-optics, (4 October 1979);

Published in SPIE Proceedings Vol. 0187:
System Aspects of Electro-optics
Harold B Jeffreys, Editor(s)