Pipeline processing for stochastic studies of telescope performance affected by thermo-elastic deformation

The change in temperature between the manufacturing environment and the operating environment of a telescope causes deformation and displacement of the mirror surfaces. The resulting displacement of the focus and a change in the aberrations need to be evaluated as part of the tolerancing procedure in the design phase of the telescope. However, the thermal properties of the materials cannot be known precisely and it is necessary to perform an analysis of a large number of models to tolerance the design. This article describes a procedure in which the output of a stochastically driven finite element model of a telescope is passed to an automated process for converting the thermally distorted telescope models to input to the physical optics package GRASP [2], processing the PO models, analysing the output and archiving all models and derived data. With this procedure it has been possible process batches of a hundred models of a 3.5 m telescope in a few hours.