Control System Design for Telescope Point Spread Function Stability Maintenance

Abstract

Clearly imaging distant celestial structures from the ground can be difficult due to interference of the atmosphere, and doing so from space is often incredibly expensive. However, there is a third option: using a balloon in order to lift the imaging system to a height devoid of most atmospheric aberrations. This paper will review pertinent aspects of the design of a balloon-borne imaging telescope which will be used in order to measure the masses of certain galaxy clusters via gravitational lensing. Following this, details of the preliminary steps in the design of a quasi-static control system for the stability maintenance of the point spread function (PSF) of the telescope will be described. In order to design the control system, we first derived a linear mapping between a lower dimensional proxy for PSFs and the positions of the mirrors. We then tested this mapping using two simulations, and the results suggest that the linear mapping is only slightly better than a random model. This prompted us to explore more sophisticated regression models.