Coupling analysis in the calibration process of electro-optical detection systems

Electro-optical detection systems should be calibrated prior to use, a commonly used method with an autocollimator and a high precision turntable may introduce large error in the calibration process. This paper analyzed the calibration process, and showed that the nature of the problem was attributed to the plane rotation around a non-orthogonal axis. The mirror's non-orthogonal rotation was divided into position rotation and mirror spinning, and the effects on autocollimator readout were obtained. Simulation results demonstrated that the coupling effects on elevation and azimuth become serious as the inclined angle and rotated angle increase. It is therefore necessary to separate the coupling error in the calibration process, which would provide more accurate data for further compensation.