Arama Sonuçları

Listeleniyor 1 - 4 / 4
  • Yayın
    Integrated opto-dynamic modeling of the 4-m DAG telescope image quality performance
    (SPIE-Int Soc Optical Engineering, 2016) Zago, Lorenzo; Guex, Benjamin; Yeşilyaprak, Cahit; Yerli, Sinan Kaan; Keskin, Onur
    The Turkish DAG 4-m telescope is currently through the final design stage. It is to be located on a 3170 m mountain top in Eastern Anatolia. The telescope will be a state-of-The art device, alt-Az mount with active primary and adjustable secondary and tertiary mirrors. Its optics design is specially aimed at being compatible with advance adaptive optics instrumentation. The ultimate performance of such a telescope results of multiple concurrent effects from many different components and active functions of the complex system. The paper presents a comprehensive integrated (end-To-end) model of the telescope, comprising in one computational sequence all structural, electrodynamics and oactive optics performance that produce the image quality at the focal plane. The model is entirely programmed in Matlab/Simulink and comprises a finite element model of structure and mirrors, dynamics modal reduction, deformation analyses of structural and optical elements, active optics feedback control in the Zernike modal space.
  • Yayın
    Turkey's next big science project: DAG the 4 meter telescope
    (SPIE-INT Soc Optical Engineering, 2014) Keskin, Onur; Yeşilyaprak, Cahit; Yerli, Sinan Kaan; Zago, Lorenzo; Jolissaint, Laurent
    The DAG (Turkish for Eastern Anatolia Observatory) 4-m telescope project has been formally launched in 2012, being fully funded by the Government of Turkey. This new observatory is to be located on a 3170 m altitude ridge near the town of Erzurum in Eastern Anatolia. First light is scheduled for late 2017. The DAG team's baseline design of the telescope consists of a Ritchey-Chretien type with alt-az mount, a focal length of 56 m and a field of view up to 30 arcmin. Multiple instruments will be located at the Nasmyth foci. The optical specifications of the telescope are set by DAG team for diffraction limited performance with active and adaptive optics. Modern mirror control technologies will allow defining in a most cost effective way the figuring requirements of the optical surfaces: the low order figuring errors of the combined optical train constituted of M1-M2-M3 are defined in terms of Zernike coefficients and referred to the M1 surface area. The high order figuring errors are defined using the phase structure functions. Daytime chilling of the closed enclosure volume and natural ventilation through suitable openings during observations will be used to ensure optimal mirror and dome seeing. A design of a ground layer adaptive optics (GLAO) subsystem is developed concurrently with the telescope. In this paper, main design aspects, the optical design and expected performance analysis of the telescope will be presented.
  • Yayın
    Project management of DAG: Eastern Anatolia Observatory
    (SPIE, 2016) Keskin, Onur; Yeşilyaprak, Cahit; Yerli, Sinan Kaan; Zago, Lorenzo; Güver, Tolga; Aliş, Sinan
    The four meter DAG (Eastern Anatolia Observatory in Turkish) telescope is not only the largest telescope in Turkey but also the most promising telescope in the northern hemisphere with a large potential to offer scientific observations with its cutting edge technology. DAG is designed to be an AO telescope which will allow both infrared and visible observations with its two Nasmyth platforms dedicated to next generation focal plane instruments. In this paper, status updates from DAG telescope will be presented in terms of; (i) in house optical design of DAG, (ii) tender process of telescope, (iii) tender process of enclosure, and (iv) tender process of the observatory building. Also status updates from the focal plane instruments project and possible collaboration activities will be presented.
  • Yayın
    DAG: A new observatory and a prospective observing site for other potential telescopes
    (SPIE, 2016) Yeşilyaprak, Cahit; Yerli, Sinan Kaan; Keskin, Onur; Güçsav, Bülent Burak
    DAG (Eastern Anatolia Observatory is read as "Dogu Anadolu Gözlemevi" in Turkish) is the newest and largest observatory of Turkey, constructed at an altitude of 3150 m in Konakll/Erzurum provenience, with an optical and nearinfrared telescope (4 m in diameter) and its robust observing site infrastructure. This national project consists of three main phases: DAG (Telescope, Enclosure, Buildings and Infrastructures), FPI (Focal Plane Instruments and Adaptive Optics) and MCP (Mirror Coating Plant). All these three phases are supported by the Ministry of Development of Turkey and funding is awarded to Atatürk University. Telescope, enclosure and building tenders were completed in 2014, 2015 and 2016, respectively. The final design of telescope, enclosure and building and almost all main infrastructure components of DAG site have been completed; mainly: road work, geological and atmospheric surveys, electric and fiber cabling, water line, generator system, cable car to summit. This poster explains recent developments of DAG project and talks about the future possible collaborations for various telescopes which can be constructed at the site.