AbstractsAstronomy & Space Science

High performance computing for adaptive optics and the Victoria open loop testbed

by Michael Fischer




Institution: University of Victoria
Department:
Year: 2009
Keywords: astronomical; telescopes; atmospheric; turbulence; UVic Subject Index::Sciences and Engineering::Engineering::Mechanical engineering
Record ID: 1856259
Full text PDF: http://hdl.handle.net/1828/1375


Abstract

This thesis addresses high performance computing in Adaptive Optics (AO) simulation and the development and demonstration of a prototype AO instrument for future Extremely Large Telescopes (ELTs). Adaptive Optics systems are used on astronomical telescopes for correcting the blurring effects of atmospheric turbulence on incoming starlight, improving image quality to that of the diffraction limit of the telescope. Extremely Large Telescopes will have primary mirror diameters in the 20 - 40 m range, driving the need for technology development in two key areas, among others: 1) adaptive optics simulation, and 2) wide field adaptive optics (WFAO). The Linear Adaptive Optics Simulator (LAOS) is at the forefront of adaptive optics simulation, opening up the capability to simulate ELTs with integrated AO systems on a single computer. This is computationally expensive and time consuming, and thus simulator performance is very important and can determine the feasibility of simulating such systems at all. Efforts were made to improve the existing LAOS performance and bring a larger range of problem sizes and AO instrument concepts including WFAO into the realm of possibility. WFAO will take advantage of the larger light collection and spatial resolution capabilities of ELTs. One WFAO instrument approach that addresses this is Multi-Object Adaptive Optics (MOAO), which will provide localized correction around a number (5 - 40) of selected science objects spread around the field of view, enabling extragalactic studies otherwise very costly to implement with other WFAO techniques. However, there are several risks that need to be retired. Many elements of an MOAO system, such as the use of atmospheric tomography, MEMS mirrors, and woofer-tweeter control have all been demonstrated to work in different lab settings and are included in advanced instrument concepts. Open loop control, however, is perhaps the greatest risk to MOAO, introducing unique requirements on the AO system. The Victoria Open Loop Testbed (VOLT) serves as a demonstration of open loop control – both on-sky at the Dominion Astrophysical Observatory's 1.2 m telescope and in the lab – to facilitate the future development of MOAO. Our goal was to demonstrate open loop control with a simple on-axis natural guide star testbed.