Integrated system modeling for evaluating the coronagraph approach to planet detection

A coronagraphic telescope is one of the several approaches proposed for finding and characterizing extrasolar planets for the Terestrial Planet Finder (TPF) mission. The coronagraph approach permits one to directly image planets but puts demanding requirements on the optical system performance. The planet flux, in the visible spectrum is typically le10 times less than the star flux. Imaging the planet requires extremely tight tolerancing of the optical system and rigorous management of the disturbance environment. To investigate many of the complex system issues, the Ball Integrated Telescope Model (ITM) was configured to do performance modeling and system trades. The individual discipline models in structural dynamics, optics, controls, signal processing, detector physics; and disturbance modeling are seamlessly integrated into one cohesive model to support efficient system level trades and analysis. The core of the model is formed by the optical toolbox implemented in MATLAB and realized in object-oriented Simulink environment. This paper describes the ITM architecture and concludes with results obtained for two potential TPF coronagraph designs. Disturbance models input into the coupled structural/optical modeling are used to explore some of the system sensitivities.