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2016 - 201922020 - 20223
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Bölüm: Işık University, Faculty of Engineering, Department of Mechanical Engineering × Konu: Adaptive optics systems ×

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Listeleniyor 1 - 5 / 5
  • Küçük Resim
    Yayın
    Status of the Focal Plane Instrumentation (FPI) Project of the 4 m DAG Telescope
    (SPIE, 2016-08-09) Keskin, Onur; Yerli, Sinan Kaan; Yeşilyaprak, Cahit; Güver, Tolga; Aliş, Sinan; Yelkenci, Filiz Korhan; Güçsav, Bülent Burak; Arabacı, Mehtap Özbey; Erol, Ayşe
    DAG (Eastern Anatolia Observatory in Turkish) will be the newest and largest (4m) observatory of Turkey in both optical (VIS) and near-infrared (NIR) Owith its robust observing site infrastructure. The telescope is designedOto house 2 Nasmyth platformes which will be dedicated to NIR and VIS observations. A collaboration has recently been established among four Turkish universities including FMV Isik University (for adaptive optics systems), Middle East Technical University (fort measurement, test and calibration purposes), Istanbul University (for new technology instruments, e.g. MKIDs) and as the coordinator Ataturk University (for obtaining NIR and VIS instruments). In this paper the status of the recently approved FPI project and its aims are presented and possible collaboration opportunities are emphasized.
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    TROIA adaptive optics system for DAG Telescope
    (SPIE, 2020-12-13) Keskin, Onur; Jolissaint, Laurent; Bouxin, Audrey; Yeşilyaprak, Cahit
    This paper presents the specifications of TROIA-TuRkish adaptive Optics system for Infrared Astronomy system, the science rationale for these specifications, and description of the site technical and environmental conditions to be taken into account in the adaptive optics (AO) system design for the Eastern Anatolia Observatory-DAG telescope. With it's 468 actuators, EMCCD camera, and the pyramid wavefront sensor configuration; TROIA is able to adapt the degree of correction to a given guide star (GS) brightness during observations. The high actuator density of TROIA AO system will allow DAG to perform astronomical observations at ExAO performances.
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    DAG 4m telescope: assembly, integration and testing
    (SPIE-Int Soc Optical Engineering, 2018-07-06) Pirnay, Olivier; Lousberg, Grégory P.; Gabriel, Eric; Marchiori, Gianpietro; Busatta, Andrea; Yeşilyaprak, Cahit; Keskin, Onur
    AMOS with EIE as a main subcontractor, was awarded a contract in November 2014 for the design, manufacturing and installation of a 4m-class telescope for the Turkish Eastern Anatolia Observatory (DAG) situated at 3170 m above the sea level in Palandöken mountains. The telescope is based on a Ritchey-Chretien configuration with two folded Nasmyth focal planes and a focal length of 56m. Diffraction-limited performances will be reached thanks to the combination of the active optics system and the adaptive optics system that will be implemented on one of the Nasmyth ports. The active optics system aims at controlling the shape of the primary mirror by means of 66 axial force actuators and positioning actively the secondary and tertiary mirrors by means of hexapods. More than 30 years of experience in testing instruments and telescopes, including optical testing, alignment, metrology, mechanical static and dynamic measurements, system identification, etc. allow to implement an adequate verification strategy combining component level verifications with factory and site test in the most efficient and reliable manner. As a main contractor, AMOS is in charge of the overall project management, the system engineering, the optical design and the active optics development. As a main sub-contractor and partner of AMOS, EIE is in charge of the development of the mount. The factory test therefore takes place in EIE premises. In this paper is shortly presented the overall design of the telescope with a review of the specification, the optical design and a description of the major sub-systems, including the optics. The assembly, integration et test plan is outlined. The assembly sequence and the tests of the active optics and the mount are discussed. Finally, the site integration and tests are explained. The process to assess the image quality of the telescope and the verification instrument developed for this purpose by AMOS are presented.
  • Küçük Resim
    Yayın
    TROIA Adaptive optics system for DAG telescope; assembly and laboratory performance prior to on-sky assessment
    (SPIE, 2022-08-29) Keskin, Onur; Jolissaint, Laurent; Bouxin, Audrey; Yeşilyaprak, Cahit
    In this article, we describe the current status of the development of TROIA* a pyramid wavefront sensor based adaptive optics system designed for DAG, a new 4 m telescope located in Eastern Anatolia, Turkey. The wavefront uses a no-noise electron-multiplied CCD camera, and the deformable mirror has a large actuators density, allowing coronagraphic science in one hand, but also system optimization for low light level or bad seeing conditions thanks to the versatility of the P-WFS. We describe the optical design, the mounting and alignment procedure and our loop control concept. Closed loop results are described, showing that while there are still many issues to fix before the sky version, the system behaves as expected.
  • Küçük Resim
    Yayın
    Eastern Anatolia Observatory (DAG): The status in 2020
    (SPIE, 2020) Yeşilyaprak, Cahit; Keskin, Onur
    East Anatolian Observatory's DAG telescope, with its 4m diameter primary mirror and VIS/IR observation capability, will be located on the Konakll-Karaya summit at an altitude of 3170 m, near the city of Erzurum, Turkey. Containing both active optics (aO) and adaptive optics (AO) systems, the first light for DAG is expected for the last quarter of 2021. DAG will be equipped with an in-flange derotator - KORAY (K-mirror Optical relAY) that will direct the light to the seeing limited Nasmyth platform containing TROIA (TuRkish adaptive Optics system for Infrared Astronomy). DAG first generation instruments will consist in a 30"FoV near-infrared (NIR) diffraction limited camera and a stellar coronagraph. In his paper, status updates from DAG telescope will be presented in terms of; (i) DAG site, (ii) Site infrastructure, (iii) current status of the observatory building, (iv) DAG optics, (v) current status of the telescope, (vi) current status of enclosure, (vi) current progress of the astronomical instruments, and (viii) status of the Optomechatronics Research Laboratory - OPAL.