Mr. Larry Stepp Profile

Larry Stepp

Retired

SPIE Involvement:

Editor | Author

Publications (24)

Proceedings Article | 22 July 2014 Paper

Paper

Preliminary design study of the TMT Telescope structure system: overview

Tomonori Usuda, Yutaka Ezaki, Noboru Kawaguchi, Kazuhiro Nagae, Atsushi Kato, Junji Takaki, Masaki Hirano, Tomoya Hattori, Masaki Tabata, Yasushi Horiuchi, Yusuke Saruta, Satoru Sofuku, Noboru Itoh, Takeharu Oshima, Takashi Takanezawa, Makoto Endo, Junji Inatani, Masanori Iye, Amir Sadjadpour, Mark Sirota, Scott Roberts, Larry Stepp

Proceedings Volume 9145, 91452F (2014) https://doi.org/10.1117/12.2055767

KEYWORDS: Telescopes, Optical instrument design, Computer aided design, Mirrors, Electroluminescence, Control systems design, Control systems, Earthquakes, Safety, Thirty Meter Telescope

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We present an overview of the preliminary design of the Telescope Structure System (STR) of Thirty Meter Telescope (TMT). NAOJ was given responsibility for the TMT STR in early 2012 and engaged Mitsubishi Electric Corporation (MELCO) to take over the preliminary design work. MELCO performed a comprehensive preliminary design study in 2012 and 2013 and the design successfully passed its Preliminary Design Review (PDR) in November 2013 and April 2014. Design optimizations were pursued to better meet the design requirements and improvements were made in the designs of many of the telescope subsystems as follows: 1. 6-legged Top End configuration to support secondary mirror (M2) in order to reduce deformation of the Top End and to keep the same 4% blockage of the full aperture as the previous STR design. 2. “Double Lower Tube” of the elevation (EL) structure to reduce the required stroke of the primary mirror (M1) actuators to compensate the primary mirror cell (M1 Cell) deformation caused during the EL angle change in accordance with the requirements. 3. M1 Segment Handling System (SHS) to be able to make removing and installing 10 Mirror Segment Assemblies per day safely and with ease over M1 area where access of personnel is extremely difficult. This requires semi-automatic sequence operation and a robotic Segment Lifting Fixture (SLF) designed based on the Compliance Control System, developed for controlling industrial robots, with a mechanism to enable precise control within the six degrees of freedom of position control. 4. CO₂ snow cleaning system to clean M1 every few weeks that is similar to the mechanical system that has been used at Subaru Telescope. 5. Seismic isolation and restraint systems with respect to safety; the maximum acceleration allowed for M1, M2, tertiary mirror (M3), LGSF, and science instruments in 1,000 year return period earthquakes are defined in the requirements. The Seismic requirements apply to any EL angle, regardless of the operational status of Hydro Static Bearing (HSB) system and stow lock pins. In order to find a practical solution, design optimization study for seismic risk mitigation was carried out extensively, including the performing of dynamic response analyses of the STR system under the time dependent acceleration profile of seven major earthquakes. The work is now moving to the final design phase from April 2014 for two years.

Proceedings Article | 17 September 2012 Paper

Paper

Thirty Meter Telescope project update

Larry Stepp

Proceedings Volume 8444, 84441G (2012) https://doi.org/10.1117/12.928006

KEYWORDS: Telescopes, Observatories, Mirrors, Adaptive optics, Prototyping, Polishing, Optical instrument design, Actuators, Sensors, Thirty Meter Telescope

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Proceedings Article | 23 July 2008 Paper

Paper

Primary mirror segmentation studies for the Thirty Meter Telescope

Curtis Baffes, Terry Mast, Jerry Nelson, Eric Ponslet, Vince Stephens, Larry Stepp, Eric Williams

Proceedings Volume 7018, 70180S (2008) https://doi.org/10.1117/12.790206

KEYWORDS: Mirrors, Telescopes, Mirror pointing, Interfaces, Error analysis, Glasses, Actuators, Astronomy, Stars, Thirty Meter Telescope

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Proceedings Article | 23 July 2008 Paper

Paper

Advancement of the segment support system for the Thirty Meter Telescope primary mirror

Eric Williams, Curtis Baffes, Terry Mast, Jerry Nelson, Benjamin Platt, R. J. Ponchione, Eric Ponslet, Shahriar Setoodeh, Mark Sirota, Vince Stephens, Larry Stepp, Alan Tubb

Proceedings Volume 7018, 701810 (2008) https://doi.org/10.1117/12.790176

KEYWORDS: Distortion, Mirrors, Monochromatic aberrations, Convolution, Glasses, Telescopes, Interfaces, Thermography, Actuators, Photovoltaics

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Proceedings Article | 10 July 2008 Paper

Paper

TMT telescope structure system: design and development progress report

Kei Szeto, Scott Roberts, Mike Gedig, Glenn Austin, Christie Lagally, Steven Patrick, Dominic Tsang, Doug MacMynowski, Mark Sirota, Larry Stepp, Peter Thompson

Proceedings Volume 7012, 70122G (2008) https://doi.org/10.1117/12.787002

KEYWORDS: Telescopes, Optical instrument design, Control systems, Structural design, Safety, Control systems design, Finite element methods, Space telescopes, Earthquakes, Thirty Meter Telescope

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Proceedings Article | 10 July 2008 Paper

Paper

TMT telescope structure system: seismic analysis and design

Dominic Tsang, Glenn Austin, Mike Gedig, Christie Lagally, Kei Szeto, Genady Sagals, Larry Stepp

Proceedings Volume 7012, 70124J (2008) https://doi.org/10.1117/12.790288

KEYWORDS: Telescopes, Optical instrument design, Earthquakes, Mirrors, Systems modeling, Space telescopes, Astronomy, Finite element methods, Complex systems, Thirty Meter Telescope

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Proceedings Article | 6 July 2006 Paper

Paper

Control and support of 4-meter class secondary and tertiary mirrors for the Thirty Meter Telescope

Dan Blanco, Myung Cho, Larry Daggert, Phil Daly, Joe DeVries, Jonathan Elias, Bruce Fitz-Patrick, Ed Hileman, Mark Hunten, Ming Liang, Mark Nickerson, Earl Pearson, Dave Rosin, Mark Sirota, Larry Stepp

Proceedings Volume 6273, 62731A (2006) https://doi.org/10.1117/12.672626

KEYWORDS: Mirrors, Actuators, Telescopes, Active optics, Control systems, Computer programming, Systems modeling, Adaptive optics, Monochromatic aberrations, Thirty Meter Telescope

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Proceedings Article | 6 July 2006 Paper

Paper

Development of the primary mirror segment support assemblies for the Thirty Meter Telescope

Eric Ponslet, Dan Blanco, Myung Cho, Terry Mast, Jerry Nelson, R. J. Ponchione, Mark Sirota, Vince Stephens, Larry Stepp, Alan Tubb, Eric Williams

Proceedings Volume 6273, 627319 (2006) https://doi.org/10.1117/12.670604

KEYWORDS: Actuators, Mirrors, Telescopes, Glasses, Monochromatic aberrations, Optical instrument design, Space telescopes, Phase modulation, Error analysis, Thirty Meter Telescope

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Proceedings Article | 26 June 2006 Paper

Paper

TMT telescope structure system: design and development

Kei Szeto, Scott Roberts, Simon Sun, Larry Stepp, Jerry Nelson, Mike Gedig, Nathan Loewen, Dominic Tsang

Proceedings Volume 6267, 62672Q (2006) https://doi.org/10.1117/12.669731

KEYWORDS: Telescopes, Mirrors, Optical instrument design, Space telescopes, Structural design, Systems modeling, Optical components, Actuators, Image quality, Thirty Meter Telescope

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Proceedings Article | 7 July 2004 Paper

Paper

The Thirty-Meter Telescope project design and development phase

Larry Stepp, Stephen Strom

Proceedings Volume 5382, (2004) https://doi.org/10.1117/12.566105

KEYWORDS: Telescopes, Optical instrument design, Adaptive optics, Observatories, Astronomy, Astronomical telescopes, Mirrors, James Webb Space Telescope, Space telescopes, Thirty Meter Telescope

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Proceedings Article | 4 February 2003 Paper

Paper

Wind loading of large telescopes

Myung K. Cho, Larry Stepp, George Angeli, David Smith

Proceedings Volume 4837, (2003) https://doi.org/10.1117/12.458191

KEYWORDS: Mirrors, Telescopes, Gemini Observatory, Wind measurement, Turbulence, Large telescopes, Optical instrument design, Segmented mirrors, Sensors, Image segmentation

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Proceedings Article | 30 January 2003 Paper

Paper

Estimating the costs of extremely large telescopes

Larry Stepp, Larry Daggert, Paul Gillett

Proceedings Volume 4840, (2003) https://doi.org/10.1117/12.459868

KEYWORDS: Telescopes, Observatories, Optical instrument design, Large telescopes, Astronomy, Mirrors, Space telescopes, Statistical analysis, Data modeling, Integrated modeling

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Proceedings Article | 30 January 2003 Paper

Paper

Giant Segmented Mirror Telescope: a point design based on science drivers

Stephen Strom, Larry Stepp, Brooke Gregory

Proceedings Volume 4840, (2003) https://doi.org/10.1117/12.459863

KEYWORDS: Mirrors, Telescopes, Adaptive optics, Optical instrument design, Control systems design, Image segmentation, Galactic astronomy, Segmented mirrors, Spectrographs, Sensors

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Proceedings Article | 30 July 2002 Paper

Paper

Characterization of wind loading of telescopes

George Angeli, Myung K. Cho, Mike Sheehan, Larry Stepp

Proceedings Volume 4757, (2002) https://doi.org/10.1117/12.489825

KEYWORDS: Mirrors, Telescopes, Turbulence, Sensors, Gemini Observatory, Mirror pointing, Wind energy, Large telescopes, Atmospheric optics, Space telescopes

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Proceedings Article | 5 November 2001 Paper

Paper

Wind buffeting effects on the Gemini 8-m primary mirrors

Myung K. Cho, Larry Stepp, Seongho Kim

Proceedings Volume 4444, (2001) https://doi.org/10.1117/12.447310

KEYWORDS: Mirrors, Sensors, Telescopes, Wind measurement, Gemini Observatory, Domes, Distortion, Large telescopes, Optical instrument design, Calibration

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Proceedings Article | 20 July 2000 Paper

Paper

Effect of Gemini primary mirror position relative to the lateral support on mirror figure

Myung K. Cho, Larry Stepp

Proceedings Volume 4003, (2000) https://doi.org/10.1117/12.391507

KEYWORDS: Mirrors, Telescopes, Gemini Observatory, Monochromatic aberrations, Optical alignment, Active optics, Spherical lenses, Systems modeling, Wavefront sensors, Stars

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Proceedings Article | 13 October 1995 Open Access

Open Access

Paper

Great ideas for teaching optics

Stephen Pompea, Larry Stepp

Proceedings Volume 2525, (1995) https://doi.org/10.1117/12.224009

KEYWORDS: Ocean optics, Optics education, Optical properties, Geometrical optics, Polarizers, Telescopes, Water, Polarization, Atmospheric optics, Visual optics

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Proceedings Article | 1 June 1994 Paper

Paper

Gemini primary mirror support system

Larry Stepp, Eugene Huang, Myung K. Cho

Proceedings Volume 2199, (1994) https://doi.org/10.1117/12.176192

KEYWORDS: Mirrors, Gemini Observatory, Telescopes, Active optics, Distortion, Error analysis, Optical instrument design, Control systems, Distributed computing, Kinematics

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Proceedings Article | 1 June 1994 Paper

Paper

Gemini primary mirror thermal management system

R. Justin Greenhalgh, Larry Stepp, Eric Hansen

Proceedings Volume 2199, (1994) https://doi.org/10.1117/12.176264

KEYWORDS: Mirrors, Coating, Gemini Observatory, Telescopes, Temperature metrology, Electrodes, Control systems, Active optics, Glasses, Thermography

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Proceedings Article | 26 March 1992 Paper

Paper

NOAO testing procedures for large optics

Larry Stepp, Gary Poczulp, Earl Pearson, Nicolas Roddier

Proceedings Volume 1618, (1992) https://doi.org/10.1117/12.58045

KEYWORDS: Mirrors, Surface finishing, Optical testing, Telescopes, Polishing, Interferometers, Aspheric lenses, Spherical lenses, Interferometry, Cameras

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Proceedings Article | 26 March 1992 Paper

Paper

Fabrication of the WIYN 3.5-m primary mirror: producing an accurate sphere

Gary Poczulp, Larry Stepp, John Richardson

Proceedings Volume 1618, (1992) https://doi.org/10.1117/12.58039

KEYWORDS: Polishing, Mirrors, Surface finishing, Glasses, Optical testing, Optical spheres, Aluminum, Polishing equipment, Thermography, Spindles

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Proceedings Article | 1 December 1991 Paper

Paper

Active optics system for a 3.5-meter structured mirror

Larry Stepp, Nicolas Roddier, David Dryden, Myung K. Cho

Proceedings Volume 1542, (1991) https://doi.org/10.1117/12.48805

KEYWORDS: Mirrors, Active optics, Control systems, Mirror structures, Telescopes, Polishing, Finite element methods, Actuators, Adaptive optics, Computing systems

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Proceedings Article | 1 July 1990 Paper

Paper

Temperature control of large honeycomb mirrors

Walter Siegmund, Larry Stepp, James Lauroesch

Proceedings Volume 1236, (1990) https://doi.org/10.1117/12.19248

KEYWORDS: Mirrors, Telescopes, Sensors, Observatories, Temperature metrology, Glasses, Astronomy, Calibration, Optical telescopes, Astronomical imaging

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Proceedings Article | 1 July 1990 Paper

Paper

3.5-m mirror project at NOAO

Larry Stepp

Proceedings Volume 1236, (1990) https://doi.org/10.1117/12.19231

KEYWORDS: Mirrors, Telescopes, Polishing, Optical testing, Distortion, Control systems, Active optics, Optical fabrication, Optical telescopes, Glasses

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Showing 5 of 24 publications

Proceedings Volume Editor (8)

SPIE Conference Volume | 4 September 2014

Ground-based and Airborne Telescopes V

SPIE Conference Volume | 20 August 2012

Ground-based and Airborne Telescopes IV

SPIE Conference Volume | 22 July 2010

Ground-based and Airborne Telescopes III

SPIE Conference Volume | 27 August 2008

Ground-based and Airborne Telescopes II

SPIE Conference Volume | 15 June 2006

Ground-based and Airborne Telescopes

Showing 5 of 8 publications

Conference Committee Involvement (9)

Ground-based and Airborne Telescopes V

22 June 2014 | Montréal, Quebec, Canada

Ground-based and Airborne Telescopes IV

1 July 2012 | Amsterdam, Netherlands

Ground-based and Airborne Telescopes III

27 June 2010 | San Diego, California, United States

Ground-based and Airborne Telescopes

23 June 2008 | Marseille, France

Ground-based and Airborne Telescopes

24 May 2006 | Orlando, Florida , United States

Showing 5 of 9 Conference Committees

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