Abstract: 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 accuracy of the measurement results, which generally can be ignored. However, the adjustment error of the autocollimation has great influence on the measurement system. In order to eliminate the system error, on the basis of theoretical analysis, a new method based on data processing to compensate the adjustment error was proposed and verified by contrast experiments. Results show that a positioning accuracy σ=0.936″, was obtained by timing experiential fine adjustment, while the positioning accuracy σ″ = 0.922″ was obtained by the proposed new method. The relative error between σ″ and σ is -1.496%, which satisfies the technical requirement. Contrast experiments also demonstrate that the proposed method is convenient and reliable.

Key words: engineering survey technology, positioning accuracy, error compensation, autocollimator, collimation error