PSSN在TMT宽视场光谱仪中的应用研究

The Research on the Application of Normalized Point Source Sensitivity in Wide Field Optical Spectrometer of the Thirty Meter Telescope

光学系统像质评价是光学设计的核心,通过对常用像质评价方法与在30 m望远镜(Thirty Meter Telescope,TMT)的像质评价中提出的归一化点源灵敏度函数(Normalized Point Source Sensitivity,PSSN)的分析比较,对PSSN在TMT宽视场光谱仪(Wide Field Optical Spectrometer,WFOS)中的应用进行了研究.包括对大气视宁度的简化模拟、TMT中M3的移动对系统PSSN的影响、WFOS中准直镜的移动对系统PSSN的影响、在不同大气湍流的条件下PSSN与天顶角的关系以及PSSN与波像差的均方根值(root mean square of wavefront error,RMS WFE)μ之间的关系.结果表明,PSSN对视宁度受限下的TMT的像质评价是有效的.

The image evaluation of optical system is the core of optical design. Based on the analysis and comparison of the PSSN （Normalized Point Source Sensitivity） proposed by the image evaluation of the TMT （Thirty Meter Telescope） and the common image evaluation method, the application of PSSN in the TMT WFOS （Wide Field Optical Spectrometer） is studied. It includes a simplified simulation of the atmospheric seeing, effects of the movement of M3 on PSSN of the system, effects of the collimating mirror movement in the WFOS on PSSN of the system, the relation between PSSN and the zenith angle under the conditions of different atmospheric turbulences, and the relation between PSSN and wavefront aberration. The results show that the PSSN is effective for the evaluation of the TMT under a limited atmospheric seeing.