Zobrazeno 1 - 10
of 66
pro vyhledávání: '"Thomas Berkefeld"'
Publikováno v:
PLoS ONE, Vol 3, Iss 10, p e3399 (2008)
Getting older is associated with a decline of cognitive and sensorimotor abilities, but it remains elusive whether age-related changes are due to accumulating degenerational processes, rendering them largely irreversible, or whether they reflect plas
Externí odkaz:
https://doaj.org/article/f533728deb054da9a37aae216c056a61
Autor:
T. Waldmann, Reza Rezaei, Thomas Berkefeld, J. Kavka, Klaus G. Strassmeier, Harald Nicklas, Axel Hofmann, D. Orozco Suárez, M. Collados Vera, R. Vasková, W. Schmidt, Michael Sigwarth, Peter Gömöry, Carsten Denker, Andreas Lagg, Alex Feller, Michal Sobotka, O. von der Lühe, S. J. González Manrique, Christoph Kuckein, P. Schwartz, Sami K. Solanki, Rolf Schlichenmaier, A. Pastor Yabar, A. Kučera, D. Soltau, H. Balthasar, Dirk Schmidt, Reiner Volkmer, J. Staude
Publikováno v:
Astronomische Nachrichten. 337:1050-1056
Arch filament systems occur in active sunspot groups, where a fibril structure connects areas of opposite magnetic polarity, in contrast to active region filaments that follow the polarity inversion line. We used the GREGOR Infrared Spectrograph (GRI
Autor:
Josep Perdigues-Armengol, Klaus Kudielka, Peter Adolph, Edgar Fischer, Mikael Feriencik, Thomas Dreischer, Zoran Sodnik, Dirk Soltau, Thomas Berkefeld
Publikováno v:
2019 IEEE International Conference on Space Optical Systems and Applications (ICSOS).
In this paper, we present the design, fabrication and factory acceptance testing results of the receive (RX) adaptive optics add-on to the ESA optical ground station (1 m telescope). The system is suited to be operated with laser communication system
Autor:
Reiner Volkmer, Miguel Esteves, Felix Krämer, Thomas Berkefeld, S. Berdyugina, Karin Gerber, Olivier Grassin, Lucia Kleint, Thomas Sonner
Publikováno v:
Astronomy & Astrophysics. 641:A27
The GREGOR telescope was inaugurated in 2012. In 2018, we started a complete upgrade, involving optics, alignment, instrumentation, mechanical upgrades for vibration reduction, updated control systems, and building enhancements and, in addition, adap
Autor:
Thomas R. Rimmele, Jose Marino, Thomas Berkefeld, Nicolas Gorceix, Dirk Schmidt, Philip R. Goode, Luke Johnson
Publikováno v:
Adaptive Optics Systems VI.
The MCAO pathfinder Clear on the 1.6-meter Goode Solar Telescope has been enabling us to advance solar MCAO from early conceptual demonstrations to science grade wide-field image correction. We report on recent improvements to the control loop and we
Publikováno v:
Adaptive Optics Systems VI.
We present improvements to the telescope and the Adaptive Optics (AO) upgrades that will be installed in 2018 to the 1.5m GREGOR solar telescope. An exchange of the telescope’s secondary mirror has improved the contrast in the AO wavefront sensor (
Autor:
Thomas Berkefeld
Publikováno v:
Adaptive Optics Systems VI.
Autor:
D. Gisler, Jan Olof Stenflo, Svetlana V. Berdyugina, Luca Belluzzi, Renzo Ramelli, E. S. Carlin, Michele Bianda, Thomas Berkefeld
Context. The scattering polarization signal observed in the photospheric Sr i 4607 {\AA} line is expected to vary at granular spatial scales. This variation can be due to changes in the magnetic field intensity and orientation (Hanle effect), but als
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::85e152bdaa95b49000a0f1e0c713602b
http://arxiv.org/abs/1803.03531
http://arxiv.org/abs/1803.03531
Autor:
Thomas Berkefeld, Erik Sucher, Oskar von der Lühe, Karin Stein, Szymon Gladysz, Detlev Sprung
Publikováno v:
Optics in Atmospheric Propagation and Adaptive Systems XX.
The image quality of ground-based solar telescopes depends on the amount of turbulence in the Earth’s atmosphere, which is strongest in layers close to the ground during daytime. Local optical turbulence affects the performance of adaptive optical
Autor:
Ines Richter, Frank Heine, Thomas Berkefeld, Daniel Tröndle, Rolf Meyer, Patricia Martin Pimentel, Edgar Fischer, Mikael Feriencik, Karen Saucke, Michael Lutzer
Publikováno v:
International Conference on Space Optics — ICSO 2016.