Digital laser ranging and tracking using a compound axis servomechanism.

Optical systems for tracking and ranging have advantages over other systems because of the inherent spatial efficiency of optical frequency energy. Plane-polarized, coherent laser beams provide a control of optical energy not previously available. Utilizing laser light, this system gives precise tracking and slant-range information at a real-time sampling rate of 200 c/s. A compound-axis servo system, made possible by a mirror system mounted on a tracking pedestal, provides angular data by tracking a laserilluminated retroreflector mounted on the target. Slant range to the retroreflector is determined by a digital-mode, frequency-modulated, cw-laser ranging system, whose resolution and sampling rate are under independent control.