Parametric Circular Aperture Segmentation Formalism

Abstract

To minimize the artifacts in Point Spread Functions (PSFs) of space telescopes such as the 6 major spikes shown in the star image observed by the James Webb Space Telescope, which are caused by the primary mirror outer boundary and the gaps between segments, an alternative method to segmentize large circular telescope mirror is proposed. From the fact that the strong spikes are due to the parallel-ness of all linear boundary edges and gaps in the current hexagonal segmentation approach, the proposed segmentation methodology minimizes such parallel-ness. The proposed method comes with a set of formulas that can assist the design process including the systematic calculation of number of segments and the size of each segment to cover the entire mirror pupil area. Some example PSFs of a few possible segmented mirrors with the proposed formalism will be presented. © 2022 SPIE.