Dr. Shui Hung Kwok Profile

Dr. Shui Hung Kwok

Senior Staff Software Engineer at WM Keck Observatory

SPIE Involvement:

Author

Proceedings Article | 13 December 2020 Poster + Presentation + Paper

Flexure updates to MOSFIRE on the Keck I telescope

Taylor Hutchison, Josh Walawender, Shui Hung Kwok

Proceedings Volume 11447, 114476A (2020) https://doi.org/10.1117/12.2562864

KEYWORDS: Telescopes, Imaging systems, Astronomical imaging, Spectroscopy, Stars, Fluorescence correlation spectroscopy, Cameras, Atmospheric corrections

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Proceedings Article | 10 July 2018 Presentation + Paper

Keck Observatory telescope control system upgrade status report

Shui Hung Kwok, Kevin Tsubota, Tomas Krasuski, Jim Lyke, Ben McCarney, Jeff Mader, Kevin McCann

Proceedings Volume 10704, 107040N (2018) https://doi.org/10.1117/12.2313876

KEYWORDS: Telescopes, Control systems, Computer programming, Mirrors, Servomechanisms, Photonic integrated circuits, Switching, Stars, Keck Observatory, Data archive systems

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Proceedings Article | 6 July 2018 Presentation + Paper

Innovations and advances in instrumentation at the W. M. Keck Observatory

Marc Kassis, Dwight Chan, Shui Kwok, Tomas Krasuski, James Lyke, Sam Ragland, Scott Lilley, Sylvain Cetre, Peter Wizinowich, Hilton Lewis, Percy Gomez, Luca Rizzi, James Larkin, Tuan Do, Michael Fitzgerald, Andy Skemer, J. Xavier Prochaska, Kyle Westfall, Ben Mazin, Dimitri Mawet, Keith Matthews, Christopher Martin, Andrew Howard, Jessica Lu, Mark Chun

Proceedings Volume 10702, 1070207 (2018) https://doi.org/10.1117/12.2312316

KEYWORDS: Adaptive optics, Telescopes, Spectrographs, Sensors, Spectroscopy, Optical fibers, Observatories, Imaging systems, Control systems, Mirrors

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Proceedings Article | 6 July 2018 Paper

Implementation of W. M. Keck Observatory's telescope control system upgrade

Tomas Krasuski, Peter Thompson, Ben McCarney, Shui Kwok, Ean James, Kevin Tsubota, Mike Pollard, Kevin McCann

Proceedings Volume 10700, 107005I (2018) https://doi.org/10.1117/12.2314165

KEYWORDS: Computer programming, Telescopes, Control systems, Information operations, Field programmable gate arrays, Mirrors, Safety, Switches, Photonic integrated circuits, Keck Observatory

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Launched in 2009, Keck Observatory’s Telescope Control System Upgrade (TCSU) project set out to improve Keck’s telescope pointing, tracking, and offsetting performance as well as increase maintainability and reliability. The project went online full time on the Keck 2 telescope in October 2017 and on the Keck 1 telescope in March 2018 after a notable delay due to a re-design of the azimuth and elevation encoder mounting systems. This paper discusses the details and challenges of implementing this large and complicated system while never requiring a shutdown of either telescope. The TCSU project replaced all of the major elements of the telescope controls, rotator and secondary mirror controls, and safety system. National Instrument’s reconfigurable I/O technology (i.e. NI RIO), with their embedded field programmable gate arrays (FPGAs), are used as the core of the telescope’s digital velocity control loop, structural filter, and tachometer filter. They were also used to create a monitoring and safety system for the rotator velocity controller as well as reading the newly installed tilt meters used to greatly improve pointing performance. Delta Tau’s family of “Brick” programmable multi-axis controllers, i.e. PMAC or BRICK, are used to control the rotator and secondary mirror. They enable better tuning and faster slew speeds for these subsystems. An Allen Bradley’s ControlLogix® controller and the family of FLEX™ Input/Output (IO) modules were used to create a distributed safety system able to handle a wide variety of signal types. This technology refresh based on commercial off the shelf equipment replaced much of our obsolete and custom equipment. A significant part of the project was the installation of new telescope azimuth and elevation position encoders based on Heidenhain’s 40 micron grading tape scales. Interpolated to a 10 nanometer resolution, the new encoders provide true 4 mas resolution in azimuth and 1 mas resolution in elevation. This is a big improvement to Keck’s position sensing when compared to the old rotary incremental encoders. The installation required a significant amount of mechanical infrastructure to house them. Additionally, two tilt meters were installed to sense the telescope’s varying vertical angle as a function of azimuth, mainly due to the azimuth bearing’s axial runout. The encoders and tilt meters are the primary reason for achieving the greatly improved pointing and tracking performance [1]. Finally, a switching solution using solid state relays and dual network switches was installed to provide seamless and rapid switching between the old and new control systems during commissioning. Although this component is a simple design and does not boast of any new technology, it is one of the key components that enabled the successful testing of the new equipment while keeping the old system operational as a backup for night time observing as well as for baseline performance comparisons. It allowed us to switch a variety of signal types and was very cost effective when compared to available products.

Proceedings Article | 8 August 2016 Paper

Improving the pointing and tracking performance of the Keck telescopes

Shui Hung Kwok, Tomas Krasuski, Jim Lyke, Jeff Mader, Kevin McCann, Kevin Tsubota

Proceedings Volume 9913, 991305 (2016) https://doi.org/10.1117/12.2231825

KEYWORDS: Telescopes, Computer programming, Control systems, Performance modeling, Calibration, Stars, Space telescopes, Data modeling, Cameras, Sensors

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Proceedings Article | 27 July 2016 Paper

Laser traffic control system upgrades for Maunakea

Paul Stomski, Randy Campbell, Tom Cumming, Russell Kackley, Shui Kwok, Jim Thomas

Proceedings Volume 9909, 99095J (2016) https://doi.org/10.1117/12.2230832

KEYWORDS: Laser guide stars, Laser scattering, Control systems, Telescopes, Astronomy, Space telescopes, Observatories, Boron, Keck Observatory, Astronomical telescopes

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Proceedings Article | 26 July 2016 Open Access

Point spread function determination for Keck adaptive optics

S. Ragland, L. Jolissaint, P. Wizinowich, M. van Dam, L. Mugnier, A. Bouxin, J. Chock, S. Kwok, J. Mader, G. Witzel, Tuan Do, M. Fitzgerald, A. Ghez, J. Lu, G. Martinez, M. Morris, B. Sitarski

Proceedings Volume 9909, 99091P (2016) https://doi.org/10.1117/12.2231814

KEYWORDS: Point spread functions, Adaptive optics, Stars, Point spread functions, Adaptive optics, Stars, Telescopes, Wavefronts, Reconstruction algorithms, Algorithm development, Space telescopes, Neodymium, Mirrors

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Proceedings Article | 6 August 2014 Paper

Creation of an instrument maintenance program at W. M. Keck Observatory

G. Hill, S. Kwok, J. Mader, G. Wirth, S. Dahm, R. Goodrich

Proceedings Volume 9149, 91491D (2014) https://doi.org/10.1117/12.2056987

KEYWORDS: Software development, Observatories, Phase modulation, Inspection, Keck Observatory, Databases, Promethium, Telescopes, Optical inspection, Visualization

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Proceedings Article | 14 July 2008 Paper

The software for MAGIQ: a new acquisition, guiding, and image quality monitoring system at the W. M. Keck Observatory

Shui Hung Kwok, Jimmy Johnson, Sean Adkins, Kevin McCann

Proceedings Volume 7019, 70190A (2008) https://doi.org/10.1117/12.789839

KEYWORDS: Cameras, Telescopes, Human-machine interfaces, Control systems, Image quality, Interfaces, Java, Software development, Stars, Prototyping

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Proceedings Article | 12 July 2008 Paper

Duty cycle metrics system for the W. M. Keck Observatory

Robert Goodrich, Shui Hung Kwok

Proceedings Volume 7016, 701617 (2008) https://doi.org/10.1117/12.789718

KEYWORDS: Telescopes, Observatories, Keck Observatory, Calibration, Stars, Sensors, Image quality, Adaptive optics, Target acquisition, Visualization

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Proceedings Article | 9 July 2008 Paper

MAGIQ at the W. M. Keck Observatory: initial deployment of a new acquisition, guiding, and image quality monitoring system

Sean Adkins, Judith Cohen, Joel Aycock, James Bell, Richard Cohen, Andrew Cooper, Bob Goodrich, Jimmy Johnson, Shui Kwok, Jim Lyke, Kevin McCann, Chris Neyman, Tom Nordin, Sergey Panteleev, Grant Tolleth, Myrna Tsubota

Proceedings Volume 7014, 70141U (2008) https://doi.org/10.1117/12.789857

KEYWORDS: Cameras, Wavefront sensors, Telescopes, Image quality, Mirrors, Image segmentation, Calibration, Imaging systems, Stars, Space telescopes

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Proceedings Article | 27 June 2006 Paper

LGS AO at W.M. Keck Observatory: routine operations and remaining challenges

David Le Mignant, Marcos van Dam, Antonin Bouchez, Jason Chin, Elizabeth Chock, Randall Campbell, Al Conrad, Steve Doyle, Robert Goodrich, Erik Johansson, Shui Kwok, Robert Lafon, James Lyke, Christine Melcher, Ronald Mouser, Douglas Summers, Paul Stomski, Cynthia Wilburn, Peter Wizinowich

Proceedings Volume 6272, 627201 (2006) https://doi.org/10.1117/12.671939

KEYWORDS: Adaptive optics, Stars, Telescopes, Laser guide stars, Sodium, Keck Observatory, Sensors, Laser safety, Calibration, Target acquisition

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Proceedings Article | 13 February 2003 Paper

Io: the movie

David Le Mignant, Franck Marchis, Shui Hung Kwok, Paola Amico, Randy Campbell, Frederic Chaffee, Albert Conrad, Adam Contos, Robert Goodrich, Grant Hill, David Sprayberry, Paul Stomski, Peter Wizinowich, Imke de Pater

Proceedings Volume 4834, (2003) https://doi.org/10.1117/12.457108

KEYWORDS: Information operations, Java, Adaptive optics, Deconvolution, Stars, Spatial resolution, Telescopes, Keck Observatory, Infrared imaging, Algorithm development

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Proceedings Article | 13 December 2002 Paper

Mira: a case study

Shui Hung Kwok, Albert Conrad

Proceedings Volume 4848, (2002) https://doi.org/10.1117/12.461305

KEYWORDS: Human-machine interfaces, Mirrors, Image segmentation, Java, Image acquisition, Image quality, Telescopes, Software development, Image processing, Alignment procedures

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Proceedings Article | 27 November 2002 Paper

Keywords revisited

Shui Hung Kwok, Richard Cohen

Proceedings Volume 4845, (2002) https://doi.org/10.1117/12.456606

KEYWORDS: Interfaces, Java, Control systems, Computer programming, Human-machine interfaces, Telescopes, Software development, Keck Observatory, Adaptive optics, Observatories

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Showing 5 of 15 publications

Conference Committee Involvement (6)

Software and Cyberinfrastructure for Astronomy VII

17 July 2022 | Montréal, Québec, Canada

Software and Cyberinfrastructure for Astronomy VI

14 December 2020 | Online Only, California, United States

Software and Cyberinfrastructure for Astronomy VI

13 December 2020 | San Diego, California, United States

Software and Cyberinfrastructure for Astronomy V

10 June 2018 | Austin, Texas, United States

Software and Cyberinfrastructure for Astronomy IV Posters

26 June 2016 | Edinburgh, United Kingdom

Showing 5 of 6 Conference Committees

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