Atmospheric turbulence effects on optical spatial coding

A common use of optical spatial coding is the application for guidance and tracking concept. ThespatialThe spatial coding is usually implemented by a rotating reticle. The spatial coding is performed on an image, like in the case of anti-aircraftanti-aircraft missiles, or on a laser beam projector, such as in the beam rider concept. Experience indicates that the lateral position measurement by optical spatial coding is strongly affected by the Modulated Transfer Function (MTF) of the optical channel. In our example, this channel consists of a laser beam generator, the atmosphere, an optical receiver and threshold logic. The analysis will demonstrate the influence of the turbulence affected edge response, scintillation effects and threshold dependent error on the line of sight (LOS) measurments. As Asa aresult, the feasibility of an adaptive threshold logic demonstrates improved accuracy of the location error.