| 1. |
- Ardeberg, Arne, et al.
(författare)
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From Euro50 towards a European ELT
- 2006
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. ; 6267 II, s. 26725-26725
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Konferensbidrag (refereegranskat)abstract
- With Euro50 as a convenient telescope laboratory, the Euro50 team has continued development aiming at a European extremely large telescope (ELT). Here, we give a progress report. The needs of science and instrumentation are briefly discussed as is the importance of photometric stability and precision. Results are reported from work on integrated modelling. Details are given concerning point-spread functions (PSFs) obtained with and without adaptive optics (AO). Our results are rather encouraging concerning AO photometry and compensation of edge sensor noise as well as regarding seeing-limited ELT operation. The current status of our development of large deformable mirrors is shown. Low-cost actuators and deflection sensors have been developed as have hierarchic control algorithms. Fabrication of large thin mirror blanks as well as polishing and handling of thin mirrors has been studied experimentally. Regarding adaptive optics, we discuss differential refraction and the limitations imposed by dispersive optical path differences (OPDs) and dispersive anisoplanatism. We report on progress in laser guide star (LGS) performance and a real-time online experiment in multi-conjugate AO (MCAO). We discuss ELTs, high-resolution spectroscopy and pupil slicing with and without use of AO. Finally, we present some recent studies of ELT enclosure options.
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| 2. |
- Browne, Michael, et al.
(författare)
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Parallelization of MATLAB for Euro50 integrated modeling
- 2004
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Ingår i: Modeling and Systems Engineering for Astronomy (Proceedings of the SPIE). - : SPIE. - 081945429X ; 5497, s. 604-610
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Konferensbidrag (refereegranskat)abstract
- MATLAB and its companion product Simulink are commonly used tools insystems modelling and other scientific disciplines. A cross-disciplinaryintegrated MATLAB model is used to study the overall performance of theproposed 50m optical and infrared telescope, Euro50. However thecomputational requirements of this kind of end-to-end simulation of thetelescope's behaviour, exceeds the capability of an individualcontemporary Personal Computer. By parallelizing the model, primarily ona functional basis, it can be implemented across a Beowulf cluster ofgeneric PCs. This requires MATLAB to distribute in some way data andcalculations to the cluster nodes and combine completed results. Therehave been a number of attempts to produce toolkits to allow MATLAB to beused in a parallel fashion. They have used a variety of techniques. Herewe present findings from using some of these toolkits and proposedadvances.
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| 3. |
- Enmark, Anita, et al.
(författare)
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Architecture of the integrated model of the Euro50
- 2006
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Ingår i: Modeling, Systems Engineering, and Project Management for Astronomy II. - : SPIE. - 0277-786X .- 1996-756X. ; 6271, s. 27114-27114
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Konferensbidrag (refereegranskat)abstract
- The Euro50 is a proposed 50m extremely large telescope for optical and infrared wavelengths. To study and predict the performance of the complete telescope system, an integrated model combining the structural model of the telescope, optics models, the control systems and the adaptive optics has been established. Wind and atmospheric disturbances are also included in the model. The model is written in MATLAB and C. It is general and modular and built around dedicated ordinary differential equation solvers. The difference in time constants between subsystems is exploited to speed up calculations. The solvers can handle discontinuities and subsystem mode changes. The high degree of modularity allows different telescope designs to be modelled by rearranging subsystem blocks. Certain subsystems, for instance adaptive optics, can also run in a standalone fashion. Parts of the model are parallelized for execution on a large shared memory machine. The resulting architecture of the integrated model and sample results using the code for different telescope models are presented.
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| 4. |
- Enmark, Anita, et al.
(författare)
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Status of the Integrated Model of the Euro50
- 2006
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Ingår i: Modeling, Systems Engineering, and Project Management for Astronomy II. - : SPIE. - 0277-786X .- 1996-756X. ; 6271, s. 27102-27102
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Konferensbidrag (refereegranskat)abstract
- The Euro50 is a proposed 50m extremely large telescope for optical and infrared wavelengths. To study and predict the performance of the complete telescope system, an integrated model combining the structural model of the telescope, optics models, the control systems and the adaptive optics has been established. Wind and atmospheric disturbances are also included in the model. The integrated model is written in MATLAB and C. To satisfy memory demands and to achieve acceptable execution times, 64-bit MATLAB is used and part of the model is run on a shared memory machine using OpenMP. We present results from simulations with a complete integrated single conjugate adaptive optics model. Various sensor and actuator geometries are evaluated. A comparison of wind loading and atmospheric turbulence effects is also presented. The model shows that the telescope will be essentially seeing limited under wind load and no AO correction.
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| 5. |
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