A case study of the role of structural/optical model fidelity in performance prediction of complex opto-mechanical instruments

This paper determines model performance prediction accuracy as a function of model fidelity for a complex opto-mechanical system. The test article is the Micro-Precision Interferometer (MPI) testbed; a ground-based hardware model of a future spaceborne interferometer. The primary modeling tool is the Integrated Modeling of Optical Systems (IMOS) package. Three models of the MPI testbed were created for this study; each with a unique optical and structural model fidelity. The paper compares disturbance transfer function predictions from the three models with measured disturbance transfer functions from the hardware testbed. Results suggest meaningful model prediction errors exist when simple models are used to represent a complex opto-mechanical system. However, modest increases in model fidelity can lead to significant improvement.