A turntable to be used in laser communication laboratory experiments needs positioning accuracy of±1.5″.In order to check the technical requirements,a high accuracy angle measurement system,composed of regular polygon error,centering device,0.2″two-dimensional optoelectronic autocollimation and supporting,was set up.The collimation error of the system was theoretically analyzed,which shows that the off-center between the regular polygon mirror and the turntable contributes little impact on the positioning a...