A Caltech Library Service

Real-Time controller (RTC) for the Narrow Field Infrared Adaptive Optics System (NFIRAOS) for TMT final design

Dunn, Jennifer and Kerley, Dan and Smith, Malcolm and Chapin, Ed and Herriot, Glen and Véran, Jean-Pierre and Boyer, Corinne and Wang, Lianqi and Gilles, Luc and Trancho, Gelys (2018) Real-Time controller (RTC) for the Narrow Field Infrared Adaptive Optics System (NFIRAOS) for TMT final design. In: Adaptive Optics Systems VI. Proceedings of SPIE. No.10703. Society of Photo-optical Instrumentation Engineers (SPIE) , Bellingham, WA, Art. No. 1070317. ISBN 9781510619593.

[img] PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


The Real-Time Controller (RTC) for the Thirty Meter Telescope (TMT) Narrow Field Infrared Adaptive Optics System (NFIRAOS) is the software and server hardware that converts wavefront error measurements into wavefront corrector demands, at the heart of the laser guide star multi-conjugate adaptive optics (MCAO) or natural guide star adaptive optics (NGS AO). The RTC takes input from up to six Shack-Hartmann Laser Guide Star wavefront sensors (LGS WFS), one high-order Natural Guide Star Pyramid Wavefront Sensor (PWFS), up to three Shack-Hartmann On-Instrument wavefront sensors (OIWFS) that are located in the client science instruments, and up to 4 on-detector guide windows (ODGW) also in the client instruments. The RTC controls two deformable mirrors conjugated to 0km (DM0) and 11.8km (DM11). DM0 is mounted on a tip/tilt stage (TTS). During the final design phase we performed prototyping to verify that off-the-shelf servers using general purpose CPUs are able to support the maximum 800 Hz frequency at which the RTC is required to operate. We also considered methods to provide live data streams to a graphical user interface without impacting the AO system performance. This paper will discusses the outcome of the impact of jitter and latency on loop speed in our prototype and an overview of the RTC pipeline, including the many “knobs” that can be turned to fine-tune the behavior of NFIRAOS in different observing modes, and under different observing conditions.

Item Type:Book Section
Related URLs:
URLURL TypeDescription
Smith, Malcolm0000-0002-3321-1432
Additional Information:© 2018 Society of Photo-optical Instrumentation Engineers (SPIE).
Group:Thirty Meter Telescope
Subject Keywords:real-time control, adaptive optics, wavefront sensors, real-time, deformable mirrors
Series Name:Proceedings of SPIE
Issue or Number:10703
Record Number:CaltechAUTHORS:20190108-161619149
Persistent URL:
Official Citation:Jennifer Dunn, Dan Kerley, Malcolm Smith, Ed Chapin, Glen Herriot, Jean-Pierre Veran, Corinne Boyer, Lianqi Wang, Luc Gilles, Gelys Trancho, "The Real-Time controller (RTC) for the Narrow Field Infrared Adaptive Optics System (NFIRAOS) for TMT final design," Proc. SPIE 10703, Adaptive Optics Systems VI, 1070317 (10 July 2018); doi: 10.1117/12.2314226
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:92150
Deposited By: Tony Diaz
Deposited On:09 Jan 2019 17:53
Last Modified:09 Mar 2020 13:19

Repository Staff Only: item control page