The SOUL systems at the Large Bincoular Telescope can be seen such as precursor for the ELT SCAO systems, combining together key technologies such as EMCCD, Pyramid WFS and adaptive telescopes. After the first light of the first upgraded system on September 2018, going through COVID and technical stops, we now have all the 4 systems working on-sky. Here, we report about some key control improvements and the system performance characterized during the commissioning. The upgrade allows us to correct more modes (500) in the bright end and increases the sky coverage providing SR(K)>20% with reference stars G$_{RP}$<17, opening to extragalcatic targets with NGS systems. Finally, we review the first astrophysical results, looking forward to the next generation instruments (SHARK-NIR, SHARK-Vis and iLocater), to be fed by the SOUL AO correction.
LBTO, in partnership with GMTO, has been developing a laser-truss-based metrology system for the active alignment of telescope main optical components. Positive initial results convinced LBTO to commence to develop a "pathfinder" integrated operational active-optics system at prime focus, utilizing this technological approach. The prime-focus active-optics system benefits LBTO directly in improved system performance and is also very useful for GMTO in developing and gaining experience with a critical technical component of the GMT Telescope Metrology System. This paper describes the current system, which is now commissioned and operates in support of regular scientific observing. Technical aspects unique to direct laser truss metrology, such as system stability, the effects of correlated and uncorrelated noise, and the benefits of channel redundancy, will be discussed. Commissioning results and general system performance will also be reported. The paper will conclude with a section discussing some of the unexpected insights and improvements that the TMS has brought about at LBT by enabling the measurement of "clean" aberration data for aberrations arising from shape change on the borosilicate primary mirrors.
With the exception of the two prime focus cameras, all the instruments on the Large Binocular Telescope (LBT) use the two advanced 672-voice-coil-actuators adaptive secondary mirrors (ASMs). Based on 10 years of ASMs operation experience, and taking advantage of new technology developments, we decided to upgrade some of the ASMs hardware, to increase their performance and reliability. In this paper, we describe these improvements, i.e., upgrade of the power backplanes used in the ASM electronic control system, integration of an accelerometer-based tip-tilt vibration suppression system and upgrade of the optical calibration interferometers.
Improved Adaptive Optics (AO) systems continue to revolutionize ground-based astronomy. Key to understanding a new AO systems capability is a quantitative measurement of performance, such as the Strehl Ratio (SR). At the Large Binocular Telescope (LBT) we have undertaken a program to monitor the performance of our AO system in regular use for science operations. Input to our analysis includes data taken specifically for this purpose during twilight and on engineering nights. We report our findings thus far and in particular discuss the challenges of collecting consistent data sets in twilight, the methods we used to overcome those challenges, and preliminary results from data collected so far.
The Giant Magellan Telescope (GMT)1 is a 25 m telescope composed of seven 8.4 m “unit telescopes”, on a common mount. Each primary and conjugated secondary mirror segment will feed a common instrument interface, their focal planes co-aligned and co-phased. During telescope operation, the alignment of the optical components will deflect due to variations in thermal environment and gravity induced structural flexure of the mount. The ultimate co-alignment and co-phasing of the telescope is achieved by a combination of the Acquisition Guiding and Wavefront Sensing system (AGWS) and two segment-edge-sensing systems2. An analysis of the capture range of the AGWS indicates that it is unlikely that that system will operate efficiently or reliably with initial mirror positions provided by open-loop corrections alone3. Since 2016 GMT have been developing a telescope metrology system, that is intended to close the gap between openloop modelling and AGWS operations. A prototyping campaign was initiated soon after receipt of laser metrology hardware in 2017. This campaign is being conducted in collaboration with the Large Binocular Telescope Observatory (LBTO), and hardware was first deployed on the LBT in August 2017. Since that time the system had been run and developed over some hundreds of hours on-sky. It has been shown to be capable of reliably measuring the relative positions of the main optics over ~ 10 m to a repeatability of ~ 1-2 microns RMS. This paper will describe the prototyping campaign to date, the basic design of the system, lessons learned and results achieved. It will conclude with a discussion of future prototyping efforts.
The Giant Magellan Telescope (GMT) is a 25-meter extremely large telescope that is being built by an international consortium of universities and research institutions. Its software and control system is being developed using a set of Domain Specific Languages (DSL) that supports a model driven development methodology integrated with an Agile management process. This approach promotes the use of standardized models that capture the component architecture of the system, that facilitate the construction of technical specifications in a uniform way, that facilitate communication between developers and domain experts and that provide a framework to ensure the successful integration of the software subsystems developed by the GMT partner institutions.
The Gemini multiconjugate adaptive optics system (GeMS) at the Gemini South telescope in Cerro Pachon is the first sodium-based multilaser guide star (LGS) adaptive optics system. It uses five LGSs and two deformable mirrors to measure and compensate for atmospheric distortions. The GeMS project started in 1999, and saw first light in 2011. It is now in regular operation, producing images close to the diffraction limit in the near-infrared, with uniform quality over a field of view of two square arcminutes. This paper is the first one in a two-paper review of GeMS. It describes the system, explains why and how it was built, discusses the design choices and trade-offs, and presents the main issues encountered during the course of the project. Finally, we briefly present the results of the system first light.
The Gemini Multi-conjugate Adaptive Optics System - GeMS, a facility instrument mounted on the Gemini South telescope, delivers a uniform, near diffraction limited images at near infrared wavelengths (0.95 microns- 2.5 microns) over a field of view of 120 arc seconds. GeMS is the first sodium layer based multi laser guide star adaptive optics system used in astronomy. It uses five laser guide stars distributed on a 60 arc seconds square constellation to measure for atmospheric distortions and two deformable mirrors to compensate for it. In this paper, the second devoted to describe the GeMS project, we present the commissioning, overall performance and operational scheme of GeMS. Performance of each sub-system is derived from the commissioning results. The typical image quality, expressed in full with half maximum, Strehl ratios and variations over the field delivered by the system are then described. A discussion of the main contributor to performance limitation is carried-out. Finally, overheads and future system upgrades are described.
The Giant Magellan Telescope Organization is designing and building a ground-based 25-meter extremely large telescope. This project represents a significant increase in complexity and performance requirements over 8-10 meter class telescope control systems. This paper presents how recent software and hardware technologies and the lessons learned from the previous generation of large telescopes can help to address some of these challenges. We illustrate our model-centric approach to capture all the functionalities and workflows of the observatory subsystems, and discuss its benefits for implementing and documenting the software and control systems. The same modeling approach is also used to capture and facilitate the development process.
With two to three deformable mirrors, three Natural Guide Stars (NGS) and five sodium Laser Guide Stars (LGS), the Gemini Multi-Conjugate Adaptive Optics System (Gemini MCAO a.k.a. GeMS) will be the first facility-class MCAO capability to be offered for regular science observations starting in 2013A. The engineering and science commissioning phase of the project was kicked off in January 2011 when the Gemini South Laser Guide Star Facility (GS LGSF) propagated its 50W laser above the summit of Cerro Pachón, Chile. GeMS commissioning has proceeded throughout 2011 and the first half of 2012 at a pace of one 6- to 10-night run per month with a 5-month pause during the 2011 Chilean winter. This paper focuses on the LGSF-side of the project and provides an overview of the LGSF system and subsystems, their top-level specifications, design, integration with the telescope, and performance throughout commissioning and beyond. Subsystems of the GS LGSF include: (i) a diode-pumped solid-state 1.06+1.32 micron sum-frequency laser capable of producing over 50W of output power at the sodium wavelength (589nm); (ii) Beam Transfer Optics (BTO) that transport the 50W beam up the telescope, split the beam five-ways and configure the five 10W beams for projection by the Laser Launch Telescope (LLT) located behind the Gemini South 8m telescope secondary mirror; and (iii) a variety of safety systems to ensure safe laser operations for observatory personnel and equipment, neighbor observatories, as well as passing aircrafts and satellites.
GeMS, the Gemini Laser Guide Star Multi-Conjugate Adaptive Optics facility system, has seen first light in December 2011, and has already produced images with H band Strehl ratio in excess of 35% over fields of view of 85x85 arcsec, fulfilling the MCAO promise. In this paper, we report on these early results, analyze trends in performance, and concentrate on key or novel aspects of the system, like centroid gain estimation, on-sky non-common path aberration estimation. We also present the first astrometric analysis, showing very encouraging results.
The Gemini Multi-Conjugate Adaptive Optics System (GeMS) began its on-sky commissioning in January 2011. The system provides high order wide-field corrections using a constellation of five Laser Guide Stars. In December 2011, commissioning culminated in images with a FWHM of 80+/-2mas at 1.65 microns (H band) over an 87 x 87 arcsecond field of view. The first images have already demonstrated the scientific potential of GeMS, and after more than a year of commissioning GeMS is finally close to completion and ready for science. This paper presents a general status of the GeMS project and summarizes the achievements made during more than a year of commissioning. The characterization of GeMS performance is presented in a companion paper: "GeMS on-sky results", Rigaut et al. 1 Here we report on the sub-systems' performance, discuss current limitations and present proposed upgrades. The integration of GeMS into the observatory operational scheme is detailed. Finally, we present the plans for next year's operations with GeMS.
We report on work being done to operate the GN Altair LGS AO system using PWFS2 to track (i.e. TT correction) with a guide star at 6′-7′ from the LGS target as opposed to an NGS TT star within the Altair FoV (25″).
The Gemini Multi-Conjugate Adaptive Optics system (GeMS) has been in commissioning in the first 5 months of 2011. In this paper we present the first results of this commissioning period and plans for the future.
CANOPUS is the facility instrument for the Gemini Multi Conjugate Adaptive Optics System (GeMS) wherein all the adaptive optics mechanisms and associated electronic are tightly packed. At an early stage in the pre-commissioning phase Gemini undertook the redesign and implementation of its chilled Ethylene Glycol Water (EGW) cooling system to remove the heat generated by the electronic hardware. The electronic boards associated with the Deformable Mirrors (DM) represent the highest density heat yielding components in CANOPUS and they are also quite sensitive to overheating. The limited size of the two electronic thermal enclosures (TE) requires the use of highly efficient heat exchangers (HX) coupled with powerful yet compact DC fans. A systematic approach to comply with all the various design requirements brought about a thorough and robust solution that, in addition to the core elements (HXs and fan), makes use of features such as high performance vacuum insulated panels, vibration mitigation elements and several environment sensors. This paper describes the design and implementation of the solution in the lab prior to delivering CANOPUS for commissioning.
MYST is the Gemini MCAO System (GeMS) high level control GUI. It is written in yorick, python and C. In this paper, we review the software architecture of MYST and its primary purposes, which are many: Real-time display, high level diagnostics, calibrations, and executor/sequencer of high level actions (closing the loop, coordinating dithers, etc).
GeMS (the Gemini Multi-conjugated adaptive optics System) is a facility instrument for the Gemini-South telescope. It will deliver a uniform, diffraction-limited image quality at near-infrared (NIR) wavelengths over an extended FoV or more than 1 arcmin across. GeMS is a unique and challenging project from the technological point of view and because of its control complexity. The system includes 5 laser guide stars, 3 natural guide stars, 3 deformable mirrors optically conjugated at 0, 4.5 and 9km and 1 tip-tilt mirror. After 10 years since the beginning of the project, GeMS is finally reaching a state in which all the subsystems have been received, integrated and, in the large part, tested. In this paper, we report on the progress and current status of the different sub-systems with a particular emphasis on the calibrations, control and optimization of the AO bench.
The Gemini MCAO system, GeMS, is currently undergoing integration and test at the Gemini South base facility. GeMS has been in the work since 2001, and is finally reaching a state in which all the subsystems, except for the 50W laser, have been received, integrated and, in the large part, tested. In this paper, after a brief description of the system, we describe selected methods and results that we have obtained during the on-going integration period.