The GTC AO system designed and developed during the last years is based on a single deformable mirror with 21 x 21 actuators, conjugated to the telescope pupil, and a Shack-Hartmann wavefront sensor with 20 x 20 subapertures, using an OCAM2 camera. The GTCAO system will provide a corrected beam with a Strehl Ratio (SR) of 0.65 in K-band with bright natural guide stars. This paper reports the updated status of the integration of GTCAO in the IAC laboratory, and the results obtained in the first tests carried out to evaluate the performance of the system, before the complete characterization and the verification of the requirements. The wavefront sensor verification has been completed, and it has been integrated in the optical bench together with the corrector optics including the CILAS deformable mirror. The calibration system, also mounted on the optical bench, includes light sources used to tune, characterise and calibrate the whole system. It also simulates the atmospheric turbulence and the telescope, delivering an aberrated wavefront used to debug the whole control system, and to test the real time control software, the servo loop and different servo control strategies. Finally the Test Camera has been also integrated at the science focus to evaluate the performance.
The Gran Telescopio Canarias Adaptive Optics (GTCAO) will measure the wavefront with a Shack-Hartmann sensor. This wavefront sensor (WFS) is based on the CCD220, an electron-multiplying CCD (EMCCD) that achieves sub-electron readout noise, increasing the signal to noise ratio when weak natural guide stars (NGS) are used as reference. GTCAO will start its operation in telescope with NGS, using only one wavefront sensor, and later it will incorporate a Laser Guide Star (LGS) and consequently a second WFS, also based on an EMCCD. Both EMCCDs and a third one used as spare, have been characterized and compared including the system gain, electron- multiplication gain, readout noise vs gain, excess noise and linearity. The EM gain calibration is important to keep all EMCCD channels in the linear regime and the camera manufacturer carries it out, but it is reported that the multiplication gain may suffer ageing and degradation even if the camera is not in use. This suggests the need to monitor this ageing. In this paper it is proposed and tested a procedure for predictive maintenance that re-characterize the system gain, electron- multiplication gain and linearity periodically in order to predict the eventual ageing of the EMCCD multiplying registers. This procedure can be carried out quickly while the detector is installed in the WFS and in operational status. In order to provide the required illumination, the GTCAO calibration system is used.
The Gran Telescopio Canarias Adaptive Optics (GTCAO) is a single-conjugated post-focal system with a Shack Hartmann wavefront sensor, and one Deformable Mirror (DM) conjugated to the pupil. The optical design for tip-tilt correction includes two different mirrors, DM and the telescope M2, being M2 also used for off-loading the DM to avoid reaching its stroke limits. This optical configuration is open to different control strategies that have been simulated with Matlab. Later it has also been simulated using Durham Adaptive optics Real-time Controller (DARC) and its AO simulator, DASP. Finally some preliminary laboratory results are presented.
The Gran Telescopio Canarias Adaptive Optics (GTCAO) is a single-conjugated post-focal system with a Shack Hartmann wavefront sensor working at visible wavelength and one Deformable Mirror (DM) conjugated to the pupil. GTCAO does not include a fast tip-tilt mirror in its optical bench so it relies on the telescope secondary mirror (M2) to correct low frequency tip-tilt and offload the DM. This paper describes specific details of the software implementation of the mirror control for GTCAO, analyses its computational needs, presents the series of tests performed on the newly designed AO closed loop, and summarises software optimizations and operating system configurations set in order to optimise computer performance in the available hardware architecture
The instrument FRIDA (inFRared Imager and Dissector for Adaptive optics) is an integral field spectrograph (near infrared) with imaging capability for being used at the Nasmyth B platform of the Gran Telescopio de Canarias (GTC), behind the Adaptive Optics (AO) system. FRIDA is the first GTC instrument to use the telescope AO system. FRIDA is a collaborative project between institutions from México, Spain and the USA. In image mode, FRIDA provides scales of 0.010, 0.020 and 0.040 arcsec/pixel and, in integral-field spectroscopy (IFS) mode, spectral resolutions R 1000, 4.500 and 30.000. FRIDA has a set of different mechanisms (such as the focal plane wheel, the filters and pupil wheels, the cameras wheel, the calibration unit, the grating carousel) that are controlled and coordinated by the FRIDA Instrument Library (IL). In this paper, we present the IL, which provides the implementation of a Device that represents the instrument FRIDA as a whole. More specifically, the IL implements the commands for setting-up and coordinating the different mechanisms of FRIDA for an observation. It moves the mechanisms, exposes the detector, and reduces and stores the data image. In addition, we also present the Observation Manager (OM) component, responsible for the execution of the science observing sequences in close coordination with the IL and GTC AO system.
The instrument FRIDA (inFRared Imager and Dissector for Adaptive optics) is an integral field spectrograph (near infrared) operating at the wavelength range of 0.9 to 2.5um with imaging capability for being used at the Nasmyth B platform of the Gran Telescopio de Canarias (GTC). FRIDA is a collaborative project led by the Instituto de Astronomía Universidad Nacional Autónoma de México (IA-UNAM, México) with the collaboration of the Instituto de Astrofísica de Canarias (IAC, Spain), Centro de Ingeniería y Desarrollo Industrial (CIDESI, México), the University of Florida (UF, USA), and the Universidad Complutense de Madrid (UCM, Spain). In imaging mode, FRIDA will provide scales of 0.010, 0.020 and 0.040 arcsec/pixel and, in IFS mode, spectral resolutions of R 1000, 4.500 and 30.000. FRIDA is the first GTC instrument to use the telescope Adaptive Optic (AO) system and it is rescheduled to be delivered to GTC shortly in 2020. Since FRIDA is a GTC instrument, the high-level control software of FRIDA is embedded within the distributed architecture of the System Control of GTC (GCS) and must fulfill the GCS software and hardware standards to control the telescope and the AO system. This paper shows an overview of the high-level control software components of FRIDA inside the GCS architecture. The main components are the Mechanisms Control System whose primary task is to control the mechanisms of FRIDA, the Data Acquisition System that interacts with the detector to take image, the Data Factory Agent whose task is to provide quality control for both engineering and scientific data, the Instrument Library component responsible for operating the devices associated to FRIDA and the Observation Manager component responsible for the execution of the observing sequences in close coordination with the GTC AO system.
FRIDA is a diffraction-limited imager and integral-field spectrometer that is being built for the adaptive-optics focus of the Gran Telescopio Canarias. In imaging mode FRIDA will provide scales of 0.010, 0.020 and 0.040 arcsec/pixel and in IFS mode spectral resolutions of 1500, 4000 and 30,000. FRIDA is starting systems integration and is scheduled to complete fully integrated system tests at the laboratory by the end of 2017 and to be delivered to GTC shortly thereafter. In this contribution we present a summary of its design, fabrication, current status and potential scientific applications.
The European Solar Telescope (EST) is a 4-meter facility to be built in Canary Islands in the near future. Extensive daytime turbulence observation campaigns with the long baseline SHABAR instrument has been carried out in the two candidate sites from 2011 up to the end of 2014. The collected data together with nighttime turbulence data allow the site characterization and the computation of average turbulence profiles. These profiles can be used to feed numerical simulations in order to take important design decisions for the multiconjugate adaptive optics (MCAO) system in the telescope. This paper describes the main tasks developed in this context up to date.
The European Solar Telescope,<i> EST</i>, (, ) is a 4-meter solar telescope to be built in the Canary Islands in the near future. In order to select the best configuration for the EST telescope facilities, thermal and <i>CFD</i> analyses have been carried out to evaluate the seeing degradation produced by the telescope environment. The aim of this study is to calculate the values of optical parameters in different configurations and to find out which one causes the lowest image quality degradation. Starting from the determination of seeing degradation along the optical path by <i>CFD</i> techniques, several configurations have been compared making it possible to decide the future development line for the <i>EST</i>.
The UDP (User Defined Program) system is a scripting framework for controlling and extending instrumentation
software. It has been specially designed for air- and space-borne instruments with flexibility, error control, reuse,
automation, traceability and ease of development as its main objectives. All the system applications are connected
through a database containing the valid script commands including descriptive information and source code. The system
can be adapted to different projects without changes in the framework tools, thus achieving great level of flexibility and
reusability. The UDP system comprises: an embedded system for the execution of scripts by the instrument software;
automatic tools for aiding in the creation, modification, documentation and tracing of new scripting language commands;
and interfaces for the creation of scripts and execution control.