FM Laser Noise Effects on Optical Doppler Radar Systems

A detailed analytical study is made of the effect of FM noise on a laser carrier frequency which is used in a Doppler radar. Both long-term drift and short-term FM noise are considered. The case of high modulation index of the noise is permitted by the theory. Forward as well as slanted beams are examined. Curves have been calculated for each case to allow rapid estimates of the bandwidth requirements to accomodate the laser noise. This, in turn, will give the resolution limit of the radar caused by that noise. A summary of the results is given.     

A Dual Scan Acquisition Technique for a Laser Communication System

A dual scan acquisition system is described in which both the transmitter and the receiver optics scan, although at different frequencies. The condition where only one station scans appears as a special case of the general approach. Curves of acquisition time versus various parameters are calculated. The effect of range is also discussed.