Mr. Brian Johnson Profile

Brian Johnson

at Vera C Rubin Observatory

SPIE Involvement:

Author

Publications (8)

Proceedings Article | 29 August 2022 Presentation + Paper

Rubin Observatory hexapods: issues and upgrades

Douglas R. Neill, Brian Johnson, Myung Cho, Felipe Daruich, Holger Drass, Mostafa Lutfi, Kevin Sirano, Roberto Tighe, Te-Wei Tsai, Oliver Wiecha

Proceedings Volume 12188, 1218817 (2022) https://doi.org/10.1117/12.2628999

KEYWORDS: Actuators, Telescopes

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Proceedings Article | 29 August 2022 Presentation + Paper

Rubin Observatory Commissioning Camera: summit integration

Brian Stalder, Kevin Reil, Christian Aguilar, Claudio Araya, Anthony Borstad, Boyd Bowdish, Myung Cho, Stephen Cisneros, Chuck Claver, Julio Constanzo, Giovanni Corvetto, Holger Drass, Frossie Economou, Erik Dennihy, Alan Eisner, Juan Fabrega, Angelo Fausti Neto, Merlin Fisher-Levine, Ivan Gonzalez, Ronald Harris, Diane Hascall, Justine Haupt, Josh Hoblitt, James Howard, Mike Huffer, Tim Jenness, David Jiménez Mejías, Brian Johnson, Tony Johnson, K. Simon Krughoff, Craig Lage, Travis Lange, Ming Liang, Juan Lopez, Margaux Lopez, Robert Lupton, Guido Maulen, Felipe Menanteau, Neill Mills, Glenn Morris, Freddy Munoz, Homer Neal, Douglas Neill, Scott Newbry, Andrei Nomerotski, Dmitry Onoprienko, Ian Ordenes, Juan Orellana, Shawn Osier, HyeYun Park, Steve Pietrowicz, Andres Plazas, Gary Poczulp, Brian Qiu, Bruno Quint, Heinrich Reinking, Michael Reuter, Tiago Ribeiro, Rodrigo Rojas, Sandra Romero, Rafe Schindler, Bill Schoening, Jacques Sebag, Alysha Shugart, Cristian Silva, Ioana Sotuela, Anthony Tache, Diego Tapia, John Thayer, Sandrine Thomas, Roberto Tighe, Tei-Wei Tsai, Max Turri, Tony Tyson, Luis Vergara, Christopher Walter, Oliver Wiecha, Van Xiong

Proceedings Volume 12184, 121840J (2022) https://doi.org/10.1117/12.2630184

KEYWORDS: Cameras, Telescopes, Imaging systems, Observatories, Interfaces, Control systems, Safety, Electronics, Device simulation

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Proceedings Article | 13 December 2020 Presentation + Paper

Rubin commissioning camera: integration, functional testing, and lab performance

Brian Stalder, Kevin Reil, Chuck Claver, Ming Liang, Tei Wei Tsai, Travis Lange, Justine Haupt, Oliver Wiecha, Margaux Lopez, Gary Poczulp, Diane Hascall, Douglas Neill, Jacques Sebag, Brian Johnson, Neill Mills, Myung Cho, Homer Neal, Scott Newbry, Shawn Osier, Rafe Schindler, Dmitry Onoprienko, Anthony Johnson, R. Glenn Morris, Max Turri, Alan Eisner, Stephen Cisneros, Van Xiong, Michael Huffer, Gregg Thayer, Ronald Harris, Anthony Borstad, Anthony Tache, William Schoening, J. Anthony Tyson, Craig Lage, Merlin Fisher-Levine, Robert Lupton, Andres Plazas, Felipe Menanteau, Htut Khine Htay Win, Stephen Pietrowicz, James Howard

Proceedings Volume 11447, 114470L (2020) https://doi.org/10.1117/12.2561132

KEYWORDS: Cameras, Large Synoptic Survey Telescope, Telescopes, Imaging systems, Optical instrument design, Electro optics, Sensors, Electronics, Control systems

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Proceedings Article | 13 December 2020 Presentation + Paper

Rubin Observatory primary tertiary mirror cell assembly: integration and functional testing

Felipe Daruich, Douglas Neill, Edward Hileman, Christian Aguilar, Constanza Araujo, Claudio Araya, Michael Booth, Andy Clements, Franco Colleoni, Christopher Contaxis, Eric Coughlin, Ron Harris, Brian Johnson, Garry Knight, Juan Lopez, Neill Mills, Dave Mills, Gary Muller, Freddy Munoz, Ian Ordenes, Jacques Sebag, Edward Stover, Sandrine Thomas, Jeff Urban, Tomislav Vucina, Oliver Wiecha, Bo Xin

Proceedings Volume 11445, 114454B (2020) https://doi.org/10.1117/12.2561670

KEYWORDS: Mirrors, Large Synoptic Survey Telescope, Telescopes, Actuators, Optical instrument design, Mirror structures, Metrology, Sensors, Integration, Glasses

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Proceedings Article | 6 July 2018 Paper

LSST hardpoints final design, fabrication, and test

Michael Booth, Andy Clements, Brian Johnson

Proceedings Volume 10700, 107003S (2018) https://doi.org/10.1117/12.2312671

KEYWORDS: Large Synoptic Survey Telescope, Mirrors, Actuators, Prototyping, Telescopes, Custom fabrication, Sensors, Optical instrument design

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Proceedings Article | 6 July 2018 Paper

LSST M1M3 figure actuator final design, fabrication, and test

Gary Muller, Edward Hileman, Felipe Daruich, Michael Warner, Oliver Wiecha, Constanza Araujo, N. Mills, Brian Johnson, Edward Stover, Michael Booth, Ron Harris, Douglas Neill, William Gressler, Andrew Serio

Proceedings Volume 10700, 107003V (2018) https://doi.org/10.1117/12.2313598

KEYWORDS: Mirrors, Actuators, Servomechanisms, Large Synoptic Survey Telescope, Telescopes, Control systems, Interfaces, Glasses, Optical fabrication, Calibration

Read Abstract +

The Large Synoptic Survey Telescope¹ (LSST) is an altitude-azimuth mounted three mirror telescope and camera. The primary (M1) and tertiary (M3) mirrors are integrated into a single, monolithic borosilicate substrate 8.42 m diameter. The annular secondary (M2) mirror is located above the M1M3 mirror and the camera is nested inside the M2. The M1M3 mirror is supported on a mirror cell by two independent systems: one system is for Active Mode and the other for Static Mode.

During observing, or Active Mode², the M1M3 mirror is supported by an array of 156 support and figure control actuators consisting of 268 pneumatic cylinders that react to gravity and inertial loads and provide figure error correction. Load cells on the actuators measure forces that are communicated to the M1M3 control system. However, the figure actuators do not define the mirror position. This is defined with six axially stiff linear actuators called hardpoints³ arranged in a hexapod pattern to restrain rigid body motion of the mirror in a kinematic fashion. By adjusting the length of each hardpoint, the mirror can be adjusted in all six degrees of freedom with respect to the cell. Displacement sensors and load cells on the hardpoints communicate displacements and forces to the control system, which processes the telemetry and issues force corrections to the figure actuators to zero out any loads and moments on the hardpoints.

In Static Mode, the M1M3 mirror is no longer supported by figure actuators and the position sensing of the hard point hexapod is inactive. A second support system consisting of 288 wire rope isolators called Static Supports come into play. The static supports mechanically capture the mirror whether in Active or Static Mode and in the event the mirror experiences motion beyond the active motion range in any direction. The static supports also safely support the mirror during seismic events for all elevation angles. In active mode, the static supports do not contact the mirror and thus, do not affect the mirror positioning or figure.

This paper focuses on the detailed design, development, testing, integration, and current status of the M1M3 pneumatic figure actuators.

Proceedings Article | 6 July 2018 Paper

LSST M1M3 active mirror support system optimized to accommodate rapid telescope motions

Felipe Daruich, Douglas Neill, Michael Warner, Edward Hileman, Myung Cho, Christoph Dribusch, Constanza Araujo, Michael Booth, Christopher Contaxis, Ron Harris, Brian Johnson, Garry Knight, Neill Mills, Gary Muller, Edward Stover, Oliver Wiecha, Bo Xin

Proceedings Volume 10700, 107003G (2018) https://doi.org/10.1117/12.2313724

KEYWORDS: Actuators, Mirrors, Telescopes, Control systems, Large Synoptic Survey Telescope, Sensors, Systems modeling, Active optics

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Proceedings Article | 6 July 2018 Paper

LSST primary/tertiary mirror cell assembly integration

Constanza Araujo-Hauck, Michael Booth, Christopher Contaxis, Andy Clements, Felipe Daruich, Ed Hileman, Brian Johnson, Neill Mills, Gary Muller, Ed Stover, Michael Warner, Oliver Wiecha, Douglas Neill, William Gressler

Proceedings Volume 10700, 1070035 (2018) https://doi.org/10.1117/12.2312231

KEYWORDS: Mirrors, Actuators, Large Synoptic Survey Telescope, Control systems, Telescopes, Optical fabrication, Sensors, Coating

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Showing 5 of 8 publications

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