Dr. Steffen Frey Profile

Dr. Steffen Frey

at Leibniz Institut fur Astrophysik Potsdam

SPIE Involvement:

Author

Publications (23)

Proceedings Article | 25 July 2024 Presentation + Paper

The fibre target alignment process of the 4MOST instrument

Roland Winkler, Ingo Stilz, Alexander Pramskiy, Weijia Sun, Pasko Roje, Thomas Liebner, Daniel Sablowski, Steffen Frey, Gerard Zins, Scott Smedley

Proceedings Volume 13101, 131010L (2024) https://doi.org/10.1117/12.3020482

KEYWORDS: Telescopes, Metrology, Cameras, Device simulation, Equipment, Calibration, Sensors

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The 4-meter Multi-Object Spectroscopic Telescope (4MOST) instrument uses 2436 individually positioned optical fibres to couple the light of targets into its spectrographs. The Fibre Target Alignment (FTA) software controls all aspects of the 4MOST instrument that are involved to position the 2448 spines of the AESOP positioner to their target locations closer than 10µm RMS, within 90 seconds. The AESOP fibre positioner provides a HTML interface which is used by the FTA software to command spine movements. The metrology system consists of four cameras, and a sophisticated software package to measure the location of fibres, which are moved by the AESOP spines. Spines reach their target typically after six to eight iterative movements, which are interlaced with metrology frames. The metrology software is capable of taking 4 images simultaneously, and reconstructing fibre positions to within 3μm RMS within five seconds. We present the FTA control software architecture, the interaction of sub-components and the different operation modes of the system. Especially the concurrent and simultaneous control of four metrology camera processes. Due to the complexity of the system, comprehensive debugging and visualization tools have been developed which allow a detailed understanding and interaction of the entire system. The graphical tool provides feedback for each individual camera stream and their combined result. It provides statistics and tools to manipulate individual spines, especially to recover them in case of entanglement. To develop the control software, a full end-to-end simulator has been created, which closes the loop between metrology image simulation, simulated fibre positioning and all control aspects in between. The metrology system uses the current spine position as presented by the AESOP positioner to render metrology camera images. Analysis and downstream computation is identical to the live software. When commanded to move spines, The AESOP simulator executes the identical steps to move spines, except sending electrical signals. After which it returns the expected spine positions after their move, which is taken as input for the next FTA iteration.

Proceedings Article | 19 July 2024 Presentation

4MOST: the 4-metre Multi-Object Spectroscopic Telescope Project at the start of commissioning

Roelof de Jong, Olga Bellido-Tirado, Joar Brynnel, Aida Ezzati Amini, Steffen Frey, Christine Füßlein, Domenico Giannone, Diana Johl, Silke Kuba, Ulrike Lemke, Genoveva Micheva, Allar Saviauk, Matthias Steinmetz, Jakob Walcher, Roland Winkler, Karin Lind, Jonathan Loveday, Vincenzo Mainieri, Jean-François Pirard, Wolfgang Gaessler, Florence Laurent, Andrea Merloni, Ramón Navarro, Alban Remillieux, Florian Rothmaier, Scott Smedley, Nicholas Walton

Proceedings Volume 13096, 130960J (2024) https://doi.org/10.1117/12.3018339

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Proceedings Article | 18 July 2024 Poster + Paper

4MOST low-resolution spectrographs AIT at AIP

Florence Laurent, Didier Boudon, Eric Daguisé, Karen Disseau, Steffen Frey, Rémi Giroud, Aurélien Jarno, Jens-Kristian Krogager, Jean-Emmanuel Migniau, Matthew Lehnert, Arlette Pecontal, Emmanuel Pécontal, Alban Remillieux, Johan Richard, Pasko Roje, Carlos E. Rodriguez Alvarez, Deborah Sobiella

Proceedings Volume 13096, 130966C (2024) https://doi.org/10.1117/12.3020061

KEYWORDS: Lawrencium, Spectrographs, Lamps, Collimators, Sensors, Optical alignment, Light emitting diodes, Interfaces, CCD image sensors, Spectral resolution

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4MOST, the 4m Multi Object Spectroscopic Telescope, is an upcoming optical, fibre-fed, MOS facility for the VISTA telescope at ESO's Paranal Observatory in Chile. Its main science drivers are in the fields of galactic archeology, high-energy physics, galaxy evolution and cosmology. The 4MOST consortium consists of several institutes in Europe and Australia under leadership of the Leibniz-Institut für Astrophysik Potsdam (AIP). 4MOST is currently in its Assembly, Integration and Tests Phase with an expected start of science operations in 2025. The design of 4MOST features 2436 fibres split into two low-resolution spectrographs (1624 fibres, three arms, 370-950 nm, R > 4000) and one high-resolution spectrograph (812 fibres, three arms, ~44-69 nm coverage each, R > 18000). The fibre positioner covers a hexagonal field of view of ~4.1 deg². The fibers are 85μm core with an output beam at f/3. CRAL has the full responsibility of the two Low Resolution Spectrographs. Each of them is composed of a 200mm beam for an off-axis collimator associated to its Schmidt corrector, three “color” arms hosting f/1.73 cameras with standard 6k x 6k 15μm pixel CCD detectors. The local acceptance reviews at CRAL for the both 4MOST Low Resolution Spectrographs were successfully passed respectively in December 2021 and October 2022. In 2022, two SPIE papers described the process performed at CRAL from the integration and alignment of the sub-assemblies up to the procedures developed to test the spectrograph and demonstrate its compliance with the requirements. Then the two LRS were partially disassembled and sent to Potsdam. They have now been fully integrated, aligned and tested at Potsdam by the CRAL team. The integration of both LRS with the others sub-systems in order to validate the global end-to-end tests is foreseen in 2024 and an installation at VISTA telescope is expected in 2025. This paper describes the assembly, integration and performances achieved at Postdam for the both Low Resolution Spectrographs. Special emphasis is put on the update of procedures and components to improve performances and meet the top-level requirements.

Proceedings Article | 18 July 2024 Poster + Paper

Preliminary characterization and verification of 4MOST in Europe

Genoveva Micheva, Olga Bellido-Tirado, Joar Brynnel, Steffen Frey, Andreas Kelz, Roelof de Jong, Allar Saviauk, Roland Winkler, Florence Laurent, Walter Seifert, Ingo Stilz, Florian Rothmaier, Alexander Pramskiy, Michael Lehmitz, Wolfgang Gaessler, Ioannis Politopoulos, Jonathan Irwin, Michael Irwin, Jens-Kristian Krogager, Gérard Zins, Andreas Quirrenbach, Wenli Xu

Proceedings Volume 13096, 1309623 (2024) https://doi.org/10.1117/12.3019870

KEYWORDS: Spectrographs, Calibration, Fiber science, Data acquisition, Telescopes, Equipment, Xenon, Observational astronomy

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SPIE Journal Paper | 14 February 2023

Assembly and alignment of the 4-metre multi-object spectroscopic telescope wide field corrector

Mark H. Cunningham, Peter Doel, David Brooks, Joar Brynnel, Roelof de Jong, Steffen Frey, Michael Schroeck, Miklos Gaebler, Daniel Sablowski, Sam Barden

JATIS, Vol. 9, Issue 01, 015002, (February 2023) https://doi.org/10.1117/12.10.1117/1.JATIS.9.1.015002

KEYWORDS: Lenses, Telescopes, Astronomical imaging, Optical alignment, Spectroscopy, Analog to digital converters, Field spectroscopy, Tolerancing, Equipment, Assembly tolerances

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Proceedings Article | 29 August 2022 Presentation + Paper

4MOST metrology system lab calibration and performance

Roland Winkler, Thomas Liebner, Deborah Sobiella, Carlos Rodriguez Alvarez, Thomas Fechner, Wilbert Bittner, Dietrich Feuerstein, Bjorn Leseberg, Thomas Hahn, Ulrike Lemke, Daniel Sablowski, Alexander Pramskiy, Florian Rothmaier, Ingo Stilz, Michael Lehmitz, Scott Smedley, Hakan Onel, Steffen Frey

Proceedings Volume 12188, 121882A (2022) https://doi.org/10.1117/12.2630358

KEYWORDS: Cameras, Mirrors, Calibration, Telescopes, Metrology, Spine, Optical alignment, Sensors, Optical components, Geometrical optics

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Proceedings Article | 29 August 2022 Poster + Paper

4MOST calibration system: design, assembly, and testing

Ioannis Politopoulos, Johan Pragt, Rik ter Horst, Ronald Roelfsema, Olga Bellido-Tirado, Joar Brynnel, Steffen Frey, Amina Helmi, Jeroen Herrewijnen, Roelof de Jong, Michael Lehmitz, Ramon Navarro, Allar Saviauk, Ray Sharples, Luke Tyas, Jurgen Schmoll, Walter Seifert, Menno de Haan, Menno Schuil, Eddy Elswijk, Eduardo Balbinot

Proceedings Volume 12184, 1218473 (2022) https://doi.org/10.1117/12.2629542

KEYWORDS: Calibration, Spectrographs, Integrating spheres, Telescopes, Fabry–Perot interferometers, Lamps, Camera shutters, Sensors, Mirrors, Lawrencium

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Proceedings Article | 29 August 2022 Poster + Paper

The assembly and alignment of the 4MOST wide field corrector

Mark Cunningham, Peter Doel, David Brooks, Joar Brynnel, Roelof de Jong, Steffen Frey, Michael Schroeck, Miklos Gaebler, Daniel Sablowski, Michael Lehmitz, Greg Smith, Sam Barden

Proceedings Volume 12184, 121846V (2022) https://doi.org/10.1117/12.2629247

KEYWORDS: Lenses, Optical alignment, Telescopes, Tolerancing, Optical fabrication, Metrology, Astronomical imaging, Assembly tolerances, Spectroscopes, Optics manufacturing

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Proceedings Article | 29 August 2022 Presentation + Paper

4MOST: the 4-metre multi-object spectroscopic telescope project in the assembly, integration, and test phase

Roelof de Jong, Olga Bellido-Tirado, Joar Brynnel, Aida Ezzati Amini, Steffen Frey, Christine Füßlein, Miklos Gäbler, Domenico Giannone, Diana Johl, Silke Kuba, Ulrike Lemke, Genoveva Micheva, Allar Saviauk, Matthias Steinmetz, Jakob Walcher, Roland Winkler, Karin Lind, Jonathan Loveday, Sofia Feltzing, Richard McMahon, Vincenzo Mainieri, Jean-François Pirard, Thomas Bensby, Maria Bergemann, Cristina Chiappini, Norbert Christlieb, Maria-Rosa Cioni, Johan Comparat, Simon Driver, Isobel Hook, Mike Irwin, Jean-Paul Kneib, Jochen Liske, Andrea Merloni, Ivan Minchev, Johan Richard, Else Starkenburg, Mark Sullivan, Clare Worley, Wolfgang Gaessler, Florance Laurent, Johan Pragt, Alban Remillieux, Florian Rothmaier, Scott Smedley, Ingo Stilz, Nicholas Walton, David Alexander, Ross Church, Scott Croom, Luke Davies, Caroline Heneka, Nikolay Kacharov, Jörg Knoche, Georges Kordopatis, Mirko Krumpe, Sarah Martell, Peder Norberg, Ingrid Pelisoli, Sanjib Sharma, Jesper Storm, Elmo Tempel

Proceedings Volume 12184, 1218414 (2022) https://doi.org/10.1117/12.2628965

KEYWORDS: Calibration, Telescopes, Spectrographs, Stars, Control systems, Metrology, Cameras, Spectroscopy, Galactic astronomy, Galaxy evolution, Active galactic nuclei

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Proceedings Article | 26 August 2022 Poster + Paper

4MOST guiding and wavefront sensing cameras: requirements and early testing

Olga Bellido-Tirado, Steffen Frey, Ulrike Lemke, Miklos Gäbler, Joar Brynnel, Gary Sims, Roger Cover, Thomas Liebner, Thomas Fechner, Thomas Hahn, Samuel Barden

Proceedings Volume 12182, 1218223 (2022) https://doi.org/10.1117/12.2629893

KEYWORDS: Cameras, Telescopes, Sensors, Imaging systems, CCD cameras, Wavefront sensors, Interfaces, Charge-coupled devices, Temperature metrology, CCD image sensors

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Proceedings Article | 13 December 2020 Paper

Verification control using DOORS

S. Egner, J. C. Gonzalez Herrera, O. Bellido-Tirado, S. Frey

Proceedings Volume 11450, 114502D (2020) https://doi.org/10.1117/12.2561976

KEYWORDS: Large telescopes

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Proceedings Article | 13 December 2020 Presentation

4MOST: the 4-metre Multi-Object Spectroscopic Telescope project status: instrument manufacturing and integration, operations development, and survey planning

Roelof de Jong, Samual Barden, Olga Bellido-Tirado, Joar Brynnel, Isabella Cesarini, Steffen Frey, Domenico Giannone, Diana Johl, Andreas Kelz, Genoveva Micheva, Hakan Önel, Matthias Steinmetz, Jakob Walcher, Roland Winkler, Sofia Feltzing, Vincenzo Mainieri, Richard McMahon, Amina Helmi, Mike Irwin, Norbert Christlieb, Cristina Chiappini, Ivan Minchev, Else Starkenburg, Thomas Bensby, Maria Bergemann, Johan Comparat, Andrea Merloni, Simon Driver, Jochen Liske, Jean-Paul Kneib, Johan Richard, Maria-Rosa Cioni, Mark Sullivan, Scott Smedley, Alban Remilleux, Florian Rothmaier, Jean-François Pirard, Ingo Stilz, Johan Pragt, Wolfgang Gaessler, Clare Worley, Man Lam, Jörg Knoche, Nicholas Walton

Proceedings Volume 11447, 1144719 (2020) https://doi.org/10.1117/12.2561036

KEYWORDS: Spectroscopes, Telescopes, Astronomical imaging, Manufacturing, Astronomical telescopes, Infrared telescopes, Spectrographs, Visible radiation, Infrared astronomy, Infrared spectroscopy

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Proceedings Article | 13 December 2020 Poster + Presentation + Paper

The instrumental profile of the 4MOST facility

Roland Winkler, Genoveva Micheva, Steffen Frey, Olga Bellido-Tirado, Roelof deJong

Proceedings Volume 11450, 114502K (2020) https://doi.org/10.1117/12.2562998

KEYWORDS: Telescopes, Spectrographs, Spectroscopes, Astronomical telescopes, Infrared telescopes, Atmospheric sensing, Astronomical imaging, Visible radiation, Infrared astronomy, Infrared spectroscopy

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Proceedings Article | 11 July 2018 Paper

4MOST low resolution spectrograph final design

Patrick Caillier, Samuel Barden, Olga Bellido-Tirado, Didier Boudon, Eric Daguisé, Steffen Frey, Florence Laurent, Jean-Emmanuel Migniau, Arlette Pécontal, Johan Richard, Allar Saviauk

Proceedings Volume 10702, 1070287 (2018) https://doi.org/10.1117/12.2313604

KEYWORDS: Lawrencium, Sensors, Charge-coupled devices, Spectral resolution, Light scattering, Spectrographs, Diffusion, Thermal effects, CCD image sensors, Optical design

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Proceedings Article | 10 July 2018 Paper

Calibration system for the 4MOST multi object fiber-fed spectrographs

Ronald Roelfsema, Johan Pragt, Rik ter Horst, Tibor Agocs, Olga Bellido, Joar Brynnel, Ariadna Calcines-Rosario, Steffen Frey, Amina Helmi, Jeroen Herrewijnen, Tom Houtsma, Roelof de Jong, Michael Lehmitz, Graham Murray, Gert Musters, Ramon Navarro, Allar Saviauk, Olivier Schnurr, Ray Sharples, Roland Winkler

Proceedings Volume 10702, 107027V (2018) https://doi.org/10.1117/12.2312473

KEYWORDS: Calibration, Fabry–Perot interferometers, Telescopes, Integrating spheres, Lamps, Spectrographs, Light sources, Beam splitters, Astronomical imaging, Spectrometers

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Proceedings Article | 10 July 2018 Paper

4MOST metrology system error analysis

Roland Winkler, Samuel Barden, Allar Saviauk, Steffen Frey, Nicolas Azais, Peter Gillingham, Scott Smedley

Proceedings Volume 10702, 1070286 (2018) https://doi.org/10.1117/12.2313522

KEYWORDS: Metrology, Cameras, Telescopes, Error analysis, Calibration, Device simulation, Imaging systems, Zemax, Image processing, Visualization

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Proceedings Article | 10 July 2018 Paper

The 4MOST numerical instrument model: TOAD

Roland Winkler, Ole Streicher, Steffen Frey, Olga Bellido-Tirado, Dionne Haynes

Proceedings Volume 10705, 1070524 (2018) https://doi.org/10.1117/12.2314020

KEYWORDS: Point spread functions, Sensors, Telescopes, Spectrographs, Device simulation, Databases, Calibration, Charge-coupled devices, Zemax

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Proceedings Article | 9 July 2018 Presentation

4MOST: the 4-metre multi-object spectroscopic telescope project at final design review (Conference Presentation)

Roelof de Jong, Samuel Barden, Olga Bellido-Tirado, Joar Brynnel, Steffen Frey, Domenico Giannone, Roger Haynes, Diana Johl, Olivier Schnurr, Jakob Walcher, Roland Winkler, Sofia Feltzing, Richard McMahon, Vincenzo Mainieri, Gabriella Baker, Patrick Caillier, Wolfgang Gaessler, Holger Mandel, Jean-François Pirard, Johan Pragt, Nicholas Walton, Thomas Bensby, Maria Bergemann, Cristina Chiappini, Norbert Christleib, Maria-Rosa Cioni, Simon Driver, Alexis Finoguenov, Amina Helmi, Mike Irwin, Jean-Paul Kneib, Jochen Liske, Andrea Merloni, Ivan Minchev, Bob Nichol, Johan Richard, Else Starkenburg, Manda Banerji, Thomas Boller, Georges Kordopatis, Mirko Krumpe, Karin Lind, Sarah Martell, Elmo Tempel, Scott Croom, Luke Davies, Morgan Fouesneau

Proceedings Volume 10702, 107021D (2018) https://doi.org/10.1117/12.2312012

KEYWORDS: Space telescopes, Telescopes, Spectroscopy, Optical instrument design, Device simulation, Astronomical imaging, Observatories, Computer simulations, Optical fibers

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We present an overview and status update of the 4MOST project at the Final Design Review. 4MOST is a major new wide-field, high-multiplex spectroscopic survey facility under development for the VISTA telescope at the Paranal Observatory of ESO. Starting in 2022, 4MOST will deploy 2436 optical fibres in a 4.1 square degree field-of-view using a fibre positioner based on the tilting spine principle. The fibres will feed one high-resolution (R~20,000) and two low-resolution (R~5000) spectrographs that all have fixed configuration, 3-channel designs with identical 6k x 6k CCD detectors. Updated performance estimates will be presented based on components already manufactured and pre-production prototypes of critical subsystems. The 4MOST science goals are mostly driven by a number of large area, space-based observatories of prime European interest: Gaia and PLATO (Galactic Archeology and Stellar Physics), eROSITA (High-Energy Sky), and Euclid (Cosmology and Galaxy Evolution). Science cases based on these observatories, along with wide-area ground-based facilities such as LSST, VISTA and VST drive the ten Consortium Surveys covering a large fraction of the Southern sky, with bright time mostly devoted to the Milky Way disk and bulge areas and the Magellanic Clouds, and the dark/gray time largely devoted to extra-galactic targets. In addition there will be a significant fraction of the fibre-hours devoted to Community Surveys, making 4MOST a true general-purpose survey facility, capable of delivering spectra of samples of objects that are spread over a large fraction of the sky. The 4MOST Facility Simulator was created to show the feasibility of the innovative operations scheme of 4MOST with all surveys operating in parallel. The simulator uses the mock catalogues created by the science teams, simulates the spectral throughput and detection of the objects, assigns the fibres at each telescope pointing, creates pointing distributions across the sky and simulates a 5-year survey (including overhead, calibration and weather losses), and finally does data quality analyses and computes the science Figure-of-Merits to assess the quality of science produced. The simulations prove the full feasibility of running different surveys in parallel.

Proceedings Article | 9 July 2018 Paper

Quality assurance and safety conformity for the 4-metre Multi-Object Spectroscopic Telescope (4MOST) project

Domenico Giannone, Gero Rupprecht, Wolfgang Ansorge, Roger Haynes, Olga Bellido, Steffen Frey, Joar Brynnel, Roelof de Jong, Arno van Kesteren, Jean-François Pirard

Proceedings Volume 10702, 1070278 (2018) https://doi.org/10.1117/12.2310145

KEYWORDS: Safety, Manufacturing, Telescopes, Control systems, Design for manufacturability, Hazard analysis, Spectroscopy, Astronomical imaging

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Proceedings Article | 5 September 2017 Presentation + Paper

4MOST optical system: presentation and design details

Nicolas Azaïs, Steffen Frey, Olga Bellido, Roland Winkler

Proceedings Volume 10401, 1040114 (2017) https://doi.org/10.1117/12.2272435

KEYWORDS: Telescopes, Spectroscopy, Optical design, Optics manufacturing, Atmospheric optics, Astronomical telescopes, Optical fibers, Infrared telescopes, Active optics, Fiber optics

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Proceedings Article | 10 August 2016 Paper

4MOST systems engineering: from conceptual design to preliminary design review

Olga Bellido-Tirado, Steffen Frey, Samuel Barden, Joar Brynnel, Domenico Giannone, Roger Haynes, Roelof de Jong, Daniel Phillips, Olivier Schnurr, Jakob Walcher, Roland Winkler

Proceedings Volume 9911, 99111Y (2016) https://doi.org/10.1117/12.2232365

KEYWORDS: Systems engineering, Telescopes, Interfaces, Spectrographs, Control systems, Sensors, Systems modeling, Matrices, Metrology, Calibration

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Proceedings Article | 9 August 2016 Paper

4MOST: the 4-metre Multi-Object Spectroscopic Telescope project at preliminary design review

Roelof de Jong, Samuel Barden, Olga Bellido-Tirado, Joar Brynnel, Steffen Frey, Domenico Giannone, Roger Haynes, Diana Johl, Daniel Phillips, Olivier Schnurr, Jakob Walcher, Roland Winkler, Wolfgang Ansorge, Sofia Feltzing, Richard McMahon, Gabriella Baker, Patrick Caillier, Tom Dwelly, Wolfgang Gaessler, Olaf Iwert, Holger Mandel, Nikolai Piskunov, Johan Pragt, Nicholas Walton, Thomas Bensby, Maria Bergemann, Cristina Chiappini, Norbert Christlieb, Maria-Rosa Cioni, Simon Driver, Alexis Finoguenov, Amina Helmi, Michael Irwin, Francisco-Shu Kitaura, Jean-Paul Kneib, Jochen Liske, Andrea Merloni, Ivan Minchev, Johan Richard, Else Starkenburg

Proceedings Volume 9908, 99081O (2016) https://doi.org/10.1117/12.2232832

KEYWORDS: Telescopes, Spectroscopy, Spectrographs, Stars, Galactic astronomy, Calibration, Lawrencium, Spine, Cameras, Metrology

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Proceedings Article | 9 August 2016 Paper

4MOST low-resolution spectrograph: design and performances

F. Laurent, Johan Kosmalski, Didier Boudon, Patrick Caillier, Eric Daguisé, Jean-Emmanuel Migniau, Arlette Pécontal, Johan Richard, Samuel Barden, Olga Bellido-Tirado, Steffen Frey, Allar Saviauk

Proceedings Volume 9908, 99087V (2016) https://doi.org/10.1117/12.2231688

KEYWORDS: Spectrographs, Optical design, Lawrencium, Sensors, Cameras, Spectral resolution, Collimators, Charge-coupled devices, Data modeling, Image quality

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Showing 5 of 23 publications

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