Self-directioning with the revolving retroreflection technique

We have developed a method for giving direction and/or position information in an optical guidance system based on the pulse position modulation property of a reflected light pulse train from a revolving retroreflector. The principle and theoretical analysis are described. Experimental verification of the one-axis, closed-loop tracking system is presented, which resulted in a static angular resolution as low as 22 microrad. This method suggests some potential applications to coordinate determinations or line-of-sight guidance systems.