Optical system performance with combined structural/ optical sensitivity to eigenvector perturbations

摘要

Many of the upcoming telescope projects propose to provide new levels of imaging performance which drives the optical design to larger and higher precision optics. This translates into tighter error budgets on the allowable image motion due mechanical disturbances. Much work has been published in this area and especially with the advances in computational capabilities, system or integrated models have been developed which allow end-to-end performance assessment. However, many of the design decisions are still based on subsystem performance metrics or only weakly consider system information in the subsystem design. A specific example is that optical design is done from a static perspective in that the sensitivities are normally evaluated separately without the inclusion of phasing information between the coefficients. This phase information is contained in the structural dynamics model in the form of the eigenvectors. Eigenvectors and perturbations of the eigenvectors can have a large effect on computed jitter because the induced optical tilts are sensitive to derivative functions. This information is ignored for several reasons - one being that complex optical design for a telescope and instrument, even with the advanced tools, still requires an experienced designer and secondly, it requires an integrated model to take advantage or even fully understand how to use this information - it requires cross-disciplinarian tools. We use two space-based systems as examples to illustrate how perturbations to these eigenvectors, due to design changes or uncertainty in the design, can have large impact on image motion.