Skip to main content

Research Repository

Advanced Search

A many-core CPU prototype of an MCAO and LTAO RTC for ELT-scale instruments

Jenkins, David R; Basden, Alastair G; Myers, Richard M

A many-core CPU prototype of an MCAO and LTAO RTC for ELT-scale instruments Thumbnail


David R Jenkins

Richard M Myers


We propose a many-core CPU architecture for Extremely Large Telescope (ELT) scale adaptive optics (AO) real-time control (RTC) for the multi-conjugate AO (MCAO) and laser-tomographic AO (LTAO) modes. MCAO and LTAO differ from the more conventional single-conjugate (SCAO) mode by requiring more wavefront sensor (WFS) measurements and more deformable mirrors to achieve a wider field of correction, further increasing the computational requirements of ELT-scale AO. We demonstrate results of our CPU based AO RTC operating firstly in SCAO mode, using either Shack-Hartmann or Pyramid style WFS processing, and then in MCAO mode and in LTAO mode using the specifications of the proposed ELT instruments, MAORY and HARMONI. All results are gathered using a CPU based camera simulator utilising UDP packets to better demonstrate the pixel streaming and pipe-lining of the RTC software. We demonstrate the effects of switching parameters, streaming telemetry and implicit pseudo open-loop control (POLC) computation on the MCAO and LTAO modes. We achieve results of <600μs latency with an ELT scale SCAO setup using Shack-Hartman processing and <800μs latency with SCAO Pyramid WFS processing. We show that our MCAO and LTAO many core CPU architecture can achieve full system latencies of <1000μs with jitters <40μs RMS. We find that a CPU based AO RTC architecture has a good combination of performance, flexibility and maintainability for ELT-scale AO systems.


Jenkins, D. R., Basden, A. G., & Myers, R. M. (2019). A many-core CPU prototype of an MCAO and LTAO RTC for ELT-scale instruments. Monthly Notices of the Royal Astronomical Society, 485(4), 5142-5152.

Journal Article Type Article
Acceptance Date Mar 1, 2019
Online Publication Date Mar 6, 2019
Publication Date Jun 30, 2019
Deposit Date Mar 8, 2019
Publicly Available Date Mar 8, 2019
Journal Monthly Notices of the Royal Astronomical Society
Print ISSN 0035-8711
Electronic ISSN 1365-2966
Publisher Royal Astronomical Society
Peer Reviewed Peer Reviewed
Volume 485
Issue 4
Pages 5142-5152
Related Public URLs


Accepted Journal Article (2.4 Mb)

Copyright Statement
© 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.

You might also like

Downloadable Citations