A Precise Optical Instrumentation Radar

An instrumentation tracker is described which provides real-time positional data on high-speed cooperative targets with precisions of ±1 m at ranges between 300 m and 10 km. Unambiguous range is determined by a precise digital FM-CW ranging technique at a rate of 15 per second. A target-mounted beacon and a narrow laser ranging beam permit measurement of target position to values much less than target dimension. Azimuth and elevation angles are read out by precision shaft angle encoders and recorded in binary form, along with range and time, on magnetic tape or directly into a real-time computer.