望远镜主镜面形误差的结构函数分析方法

Structure Function Analysis of Telescope Primary Mirror Figure Errors

望远镜主镜面形误差的指标制定、分析以及评价方法对主镜加工具有重要的指导意义。提出一种结构函数分析方法,利用它分析了大气湍流对望远镜系统成像质量的影响,制定出主镜面形加工误差的指标要求;通过建立泽尼克多项式与结构函数的直接转化关系,实现了对主镜面形误差的有效评价,给出了具体的转化步骤及结果;通过巨型麦哲伦望远镜(GMT)实例对分析过程进行了具体说明。结构函数分析方法与整镜均方根(RMS)波像差等方法相比,能更准确及完善地评价望远镜主镜的面形误差,对镜面加工更具指导意义。

The methods of specification, analysis and evaluation on telescope primary mirror figure error have an important instructive meaning to mirror fabrication. A structure function analysis method is introduced. Firstly, the influence of atmospheric turbulence on image quality is analyzed and the specification on mirror figure error is determined using the structure function analysis method. Then the evaluation on mirror figure error and the guidance of mirror processing by conversion from Zernike polynomial to structure function are achieved. The conversion processes and results have been described. Finally, the analysis processes mentioned above are illustrated in detail by an example of Giant Magellan Telescope （GMT）. The structure function analysis method which has a greater guiding significance can evaluate the mirror figure error accurately and perfectly and shows advantages over the root-meansquare （RMS） wave aberration method.