为了更好地评价 30 m望远镜三镜 (TMT M3)的反射镜, 本文结合系统频域特征以及斜率均方根, 对于其检测、评价的基本原理进行研究。首先根据斜率均方根 (slope RMS)的定义, 基于正弦多项式, 对于其基本性质进行推导与分析; 然后, 针对斜率测量, 提出 slope RMS的分离与合成方法, 为提出符合 TMT招标方要求的检测评价方法提供理论基础; 最后, 将本文方法应用于 TMT三镜仿真数据, 检验了本文假设的正确性与方法的可行性。

We investigate a new metric slope Root Mean Square (RMS) for characterizing the performance and for large telescope such as TMT tertiary mirror. The metric can multiply the errors which derived from the low order aberration, such as Zernike polynomials and other frequency composition. It represents the efficiency lose due to mid and high-spatial frequency components in frequency domain. The metric also properly counts for the optic error of the mirror itself such as the deviations from a perfect surface and metrology measurement errors. We also numerically confirm this feature for the TMT M3. We hope the work of this paper will be useful for the metrology of TMT.