These instruments were developed from theodolites by the addition of a movie camera, adding the ability to track a vehicle in flight and so obtain continuous trajectory data.
The employment of optics at a missile range may become highly significant in obtaining these data, if the atmosphere permits reasonably unobstructed observation, and if, moreover, an all-land test area makes possible optimum siting of instruments for most desirable look angles.
Under these conditions, optics in general, and photogrammetry in particular, correlated with other instrumentation systems, can provide effective and accurate data of target trajectory.
Cinetheodolites are employed in synchronized pairs, and azimuth/elevation data recorded on film is later reduced by trigonometry to establish position and movement of the target at a given moment.
The USA instruments served wartime and postwar aviation research and aircraft/missile evaluation (White Sands Test Base/Missile Range) until 1950 and the arrival of the more capable German Askania units.