Influence Matrix Creation for a Large Secondary Mirror Active Optics

Abstract

The main objective of this thesis is to verify the advantages and disadvantages of different ways of creating influence matrices. Based on the previous studies about the active optics, four different influence matrices, Unit, Combined, Singular Value Decomposition (SVD) and Normal, are constructed using finite element analysis for the comparison. The secondary mirror of Large Synoptic Survey Telescope has been utilized as a reference. This procedure developed from the reference is applicable to any large telescope. The root mean square of the optical displacements after the finial compensation is a variable to describe the optical surface quality.In addition, the various factors contributing to the final optical aberration of each method have been investigated. For Unit method, the maximum force limit has been altered to check the importance of the actuator performance level. The number of modes used in SVD and Normal methods is changed to check the contribution of higher order modal shapes.