基于半光程差的天线反射面型面精度检测

Base on semi-optical path difference of antenna reflector surface accuracy detection

型面拟合最小量的选取是天线面板型面检测中的关键技术之一.天线表面各点半光程差的均方根是衡量天线型面精度的指标.根据圆锥曲面的几何定义及其光学性质,提出了圆锥曲面天线面板半光程差的直接计算方法,给出了基于半光程差的非线性最小二乘曲面拟合算法.以旋转抛物面天线面板为例,通过模拟和实际测量,对比分析了分别选取轴向误差和半光程差作为最小量拟合计算结果.试验验证了选取半光程差作为最小量拟合的算法具有更高的数值计算精度及稳定性.

The selection of minimum value of surface fitting is one of the key technologies refer to the antenna panel surface detection. The antenna surface root-mean-square of semi-optical path difference is an index of antenna surface accuracy. A direct calculation method of semi-optical path difference （OPD） was presented according to the geometric definition of conic surface and its optical properties. The nonlinear least squares curve fitting algorithm based on the semi-optical path difference was described. Employing a parabolic reflector panel as the sample, through simulation and actual measurements, the fitting results were contrastively analyzed while selected axial deviation and semi-optical path difference as minimum value respectively. The experiments verifying the fitting method based on semi-optical path difference is more precision and stability.