Statistical analysis of the surface figure of the James Webb Space Telescope

摘要

The performance of an optical system is best characterized by either the point spread function (PSF) or the opticaltransfer function (OTF). However, for system budgeting purposes, it is convenient to use a single scalar metric, or acombination of a few scalar metrics to track performance. For the James Webb Space Telescope, the Observatorylevel requirements were expressed in metrics of Strehl Ratio, and Encircled Energy. These in turn were converted tothe metrics of total rms WFE and rms WFE within spatial frequency domains. The 18 individual mirror segmentsfor the primary mirror segment assemblies (PMSA), the secondary mirror (SM), tertiary mirror (TM), and FineSteering Mirror have all been fabricated. They are polished beryllium mirrors with a protected gold reflectivecoating. The statistical analysis of the resulting Surface Figure Error of these mirrors has been analyzed. Theaverage spatial frequency distribution and the mirror-to-mirror consistency of the spatial frequency distribution arereported. The results provide insight to system budgeting processes for similar optical systems.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.