19 research outputs found
Alignment and preliminary outcomes of an ELT-size instrument to a very large telescope: LINC-NIRVANA at LBT
LINC-NIRVANA (LN) is a high resolution, near infrared imager that uses a
multiple field-of-view, layer-oriented, multi-conjugate AO system, consisting
of four multi-pyramid wavefront sensors (two for each arm of the Large
Binocular Telescope, each conjugated to a different altitude). The system
employs up to 40 star probes, looking at up to 20 natural guide stars
simultaneously. Its final goal is to perform Fizeau interferometric imaging,
thereby achieving ELT-like spatial resolution (22.8 m baseline resolution). For
this reason, LN is also equipped with a fringe tracker, a beam combiner and a
NIR science camera, for a total of more than 250 optical components and an
overall size of approximately 6x4x4.5 meters. This paper describes the
tradeoffs evaluated in order to achieve the alignment of the system to the
telescope. We note that LN is comparable in size to planned ELT
instrumentation. The impact of such alignment strategies will be compared and
the selected procedure, where the LBT telescope is, in fact, aligned to the
instrument, will be described. Furthermore, results coming from early
night-time commissioning of the system will be presented.Comment: 8 pages, 6 pages, AO4ELT5 Proceedings, 201
Solving the MCAO partial illumination issue and laboratory results
Telescopes or instruments equipped with Multi-Conjugate Adaptive Optics (MCAO) provide uniform turbulence correction over a wide Field of View (FoV), thereby overcoming the problems of isoplanatism and enabling previously challenging science. LINC-NIRVANA (LN), the German-Italian near-infrared high-resolution imager for the Large Binocular Telescope (LBT), has an advanced and unique MCAO module, which uses the Optical Co-addition of Layer- Oriented Multiple-FoV Natural Guide Star approach to MCAO with pyramid wavefront sensing. The layer-oriented wavefront correction can be performed by conjugating the Deformable Mirrors (DM) and the respective Wavefront Sensors (WFS) to the corresponding atmospheric layers. LN corrects for the aberrations in two different layers. The ground layer, conjugated to the telescope pupil 100m above LBT, is corrected by the Ground-layer Wavefront Sensors (GWS) driving the LBT adaptive secondary mirrors, and a higher layer 7.1km above the telescope is corrected by the High-layer Wavefront Sensors (HWS) driving a pair of Xinetics DMs on the LN bench. At the ground layer, the footprints of the stars overlap completely and every star footprint illuminates the entire pupil-plane. However, for a higher layer, the footprints do not overlap completely and each star illuminates a different region of the conjugated plane. Lack of stars, therefore, results in some regions in this "meta-pupil"-plane not being illuminated, implying no information regarding the aberrations in these areas. The optimum way of correcting the high layer, given this limited information, is the crux of the "partial illumination issue". In this paper, we propose a solution for this issue and discuss laboratory results from the aligned LN bench in the lab. Currently, LN has completed the re-integration and re-alignment at LBT. In early June 2016, we tested our partial illumination algorithm in the instrument's final configuration in the LBT mountain lab, using simulated stars. On sky testing will begin in late 2016
QCD and strongly coupled gauge theories : challenges and perspectives
We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly coupled, complex systems in particle and condensed-matter physics, as well as to searches for physics beyond the Standard Model. We also discuss how success in describing the strong interaction impacts other fields, and, in turn, how such subjects can impact studies of the strong interaction. In the course of the work we offer a perspective on the many research streams which flow into and out of QCD, as well as a vision for future developments.Peer reviewe
IDL-based AO control software for laboratory tests
LINC-NIRVANA (LN) \citep{herbst04} is a German-Italian Fizeau (imaging) interferometer for the Large Binocular Telescope (LBT) on Mt. Graham in Arizona. The development of the final LINC-NIRVANA instrument control software requires a sophisticated and well structured software design as well as a special laboratory software tool to support the ongoing integration and tests of the developed hardware for LINC-NIRVANA. In this paper we present an IDL-based engineering application for calibration and laboratory testing of the adaptive optic control loop of astronomical instruments. This engineering application provides control of the entire hardware manually and completely autonomously. The benefit of this application is the high flexibility and extendability due to the modular and object-oriented design. Furthermore the engineering application is based on the hierarchical, distributed service-oriented common software that allows the application to be run on any host in a network and control the hardware remotely
On-sky verification of a solution to the MCAO partial illumination issue and wind-predictive wavefront control
We have tested and confirmed the proper functioning of our solution to the MCAO partial illumination issue in the context of the LINC-NIRVANA (LN) MCAO module, both in the laboratory and on-sky. We present the results in this paper. Availability of direct AO-telemetry for individual layers from the LN MCAO system can be potentially used to improve not only the stability of the independent AO loops, but also the wavefront sensor efficiency. We introduce this idea, called "wind- predictive wavefront control.
On-sky verification of a solution to the MCAO partial illumination issue and wind-predictive wavefront control
We have tested and confirmed the proper functioning of our solution to the MCAO partial illumination issue in the context of the LINC-NIRVANA (LN) MCAO module, both in the laboratory and on-sky. We present the results in this paper. Availability of direct AO-telemetry for individual layers from the LN MCAO system can be potentially used to improve not only the stability of the independent AO loops, but also the wavefront sensor efficiency. We introduce this idea, called "wind- predictive wavefront control.
Installation and commissioning of the LINC-NIRVANA near-infrared MCAO imager on LBT
This paper reports on the installation and initial commissioning of LINC-NIRVANA (LN), an innovative high resolution, near-infrared imager for the Large Binocular Telescope (LBT). We present the delicate and difficult installation procedure, the culmination of a re-integration campaign that was in full swing at the last SPIE meeting. We also provide an update on the ongoing commissioning campaigns, including our recent achievement of First Light. Finally, we discuss lessons learned from the shipment and installation of a large complex instrument