Numerical modeling of optical/infrared interferometers for astronomy

Abstract

This article presents a new approach to optical modeling of astronomical interferometers as part of a dynamic 'end-to- end' instrument simulation. In a specifically developed modeling tool the optical signal flow from the observed source to the detector is computed.A ray tracing algorithm forms the basis of the program. Extended by program modules for polarization and radiometry this allows to model geometrical optical wavefront propagations and to calculate the calibrated power flux through the system. When superposing electric field distributions originating from different interferometer arms the program takes temporal coherence effects into account. These can be modeled by specifying the frequency spectrum of the observed source. A diffraction model simulates optical imaging and diffraction losses. The optical modeling tool provides interfaces for integration into an end-to-end simulation environment. In addition to the simulation of ground- and space-based interferometers the software can be applied to a great variety of other optical instruments.