为了提高大口径平面镜面形检测的精度和效率，提出了一种新的五棱镜扫描法。该方法采用径向扫描的方式，使用一个扫描的五棱镜和一台自准直仪来测量表面倾斜角的差值，然后将被测平面镜的面形表示为Zemike多项式的线性组合，再利用表面倾斜角的差值建立方程组，最后采用最小二乘法计算得到被测平面镜的面形。
In order to improve the accuracy and efficiency of large aperture planar mirror shape detection, a new pentaprism scanning method is proposed. The method uses a scanning Pentagram and an autocollimator to measure the difference of the surface tilt angle. Then the surface of the measured plane mirror is expressed as a linear combination of Zemike polynomials. Then the equations are established by the difference of the surface tilt angle. Finally, the measured surface is calculated by least square method. The shape of a plane mirror.