Real-time control (RTC) systems and hardware considerations for next generation adaptive optics (AO) RTC

Abstract

Twenty years ago, the Altair RTC processed a set of gradients from a 12×12 grid of gradients into actuator commands for the 177 DM actuators using a single-threaded process to perform a matrix vector multiply (MVM). Now, twenty years later, NRC Herzberg is building Narrow Field Infrared Adaptive Optics System (NFIRAOS) for the Thirty Meter project, a multi-conjugate AO system consisting of six LGS WFS, one natural guide star pyramid WFS and two deformable mirrors. The NFIRAOS RTC converts gradients from six 60x60 gradient grids into commands for the approximately 7650 actuators of the two DMs. The NFIRAOS RTC MVM computation is several orders of magnitude larger than the Altair RTC and requires dozens of threads. This paper reports on a literature search of the current AO system specifications and future AO systems, and then discusses the Herzberg Extensible Adaptive Real-Time controller (HEART) toolkit which is being used for various future RTC’s. This will highlight some of the design challenges for different size projects and design considerations that have been taken into account during the build of HEART will also be highlighted.