Wavefront sensing and the active optics system of the dark energy camera

Aaron Roodman; Kevin Reil; Chris Davis

doi:10.1117/12.2056904

Translator Disclaimer

10 September 2014 Wavefront sensing and the active optics system of the dark energy camera

Aaron Roodman, Kevin Reil, Chris Davis

Author Affiliations +

Proceedings Volume 9145, Ground-based and Airborne Telescopes V; 914516 (2014) https://doi.org/10.1117/12.2056904
Event: SPIE Astronomical Telescopes + Instrumentation, 2014, Montréal, Quebec, Canada

Abstract

Wavefront sensing and the Active Optics System (AOS) of the Dark Energy Camera (DECam) at the CTIO 4-meter Blanco telescope are described. DECam utilizes four pairs of intra/extra-focal CCDs located on the edge of the focal plane for wavefront sensing. Out-of-focus stars are selected, individually ﬁt to a pupil plane Zernike expansion and then collectively analyzed in the time between exposures. The AOS uses this information to control the prime-focus camera’s ﬁve degrees of freedom. The AOS is now in routine use, operating with unsupervised control of the focus and camera alignment, both for the Dark Energy Survey and community observing. The design, commissioning and operation of the AOS along with results from the wavefront measurements are described. In particular, wavefront measurements of the complete optical system, including primary mirror aberrations, are shown. Lastly, preliminary results using these wavefront measurements to model the DECam point spread function are presented.

Citation Download Citation

Aaron Roodman, Kevin Reil, and Chris Davis "Wavefront sensing and the active optics system of the dark energy camera", Proc. SPIE 9145, Ground-based and Airborne Telescopes V, 914516 (10 September 2014); https://doi.org/10.1117/12.2056904

ACCESS THE FULL ARTICLE