从五角棱镜的原理和特性出发,叙述了利用五角棱镜扫描建立大平面基准过程中,由于加工角差和当五角棱镜相对入射光束有相对运动时其出射光束的横移对平面基准的影响,提出了用衍射成像技术消除光束横移,数据计算修正棱镜的角度差的影响。

According to the operating principle and characteristic of pentagonal prism, it is analyzed that the fabrication error of the prism angles and the effect of lateral displacement of exit beam when the prism has a motion relative to the incident beam on the accuracy of the datum plane to be established. The Fresnel diffraction imaging technique is used to eliminate the effect of the lateral displacement and data calculating is used to calibrate the fbrication error of the angles.