Since the beginning of the development of the Gran Telescopio Canarias (GTC), an Adaptive Optics (AO) system was considered necessary to exploit the full diffraction-limited potential of the telescope. The GTC AO system designed during the last years is based on a single deformable mirror 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.
Most of the subsystems have been manufactured and delivered. The upgrade for the operation with a Laser Guide Star (LGS) system has been recently approved. The present status of the GTCAO system, currently in its laboratory integration phase, is summarized in this paper.
The Adaptive optics for GTC is a single conjugated post focal AO system placed in the Nasmyth platform over a static optical table. It has been designed initially for natural guide star and in the later project phase adapted to one laser guide star. The AO system is composed of the following subsystems: wavefront corrector, wavefront sensor, structure, calibration system and test camera. This paper presents the hardware electronics to support all these subsystems including a real time control introduction.
OSIRIS multi object spectrograph uses a set of user-customised-masks, which are manufactured on-demand. The
manufacturing process consists of drilling the specified slits on the mask with the required accuracy. Ensuring that slits
are on the right place when observing is of vital importance.
We present a tool for checking the quality of the process of manufacturing the masks which is based on analyzing the
instrument images obtained with the manufactured masks on place. The tool extracts the slit information from these
images, relates specifications with the extracted slit information, and finally communicates to the operator if the
manufactured mask fulfills the expectations of the mask designer. The proposed tool has been built using scripting
languages and using standard libraries such as opencv, pyraf and scipy. The software architecture, advantages and limits
of this tool in the lifecycle of a multiobject acquisition are presented.
One of the main problems facing development teams working on instrument control systems consists on the need to
access mechanisms which are not available until well into the integration phase. The need to work with real hardware
creates additional problems like, among others: certain faults cannot be tested due to the possibility of hardware damage,
taking the system to the limit may shorten its operational lifespan and the full system may not be available during some
periods due to maintenance and/or testing of individual components.
These problems can be treated with the use of simulators and by applying software/hardware standards. Since
information on the construction and performance of electro-mechanical systems is available at relatively early stages of
the project, simulators are developed in advance (before the existence of the mechanism) or, if conventions and standards
have been correctly followed, a previously developed simulator might be used.
This article describes our experience in building software simulators and the main advantages we have identified, which
are: the control software can be developed even in the absence of real hardware, critical tests can be prepared using the
simulated systems, test system behavior for hardware failure situations that represent a risk of the real system, and the
speed up of in house integration of the entire instrument. The use of simulators allows us to reduce development, testing
and integration time.
OSIRIS (Optical System for Imaging and low Resolution Integrated Spectroscopy) was the optical Day One instrument
for the 10.4m Spanish telescope GTC. It is installed at the Observatorio del Roque de Los Muchachos (La Palma, Spain).
This instrument has been operational since March-2009 and covers from 360 to 1000 nm. OSIRIS observing modes
include direct imaging with tunable and conventional filters, long slit and low resolution spectroscopy. OSIRIS wide
field of view and high efficiency provide a powerful tool for the scientific exploitation of GTC. OSIRIS was developed
by a Consortium formed by the Instituto de Astrofísica de Canarias (IAC) and the Instituto de Astronomía de la
Universidad Nacional Autónoma de México (IA-UNAM). The latter was in charge of the optical design, the manufacture
of the camera and collaboration in the assembly, integration and verification process. The IAC was responsible for the
remaining design of the instrument and it was the project leader. The present paper considers the development of the
instrument from its design to its present situation in which is in used by the scientific community.
This article presents a case study on developing a software product line for data acquisition systems in astronomy based
on the Exemplar Driven Development methodology and the Exemplar Flexibilization Language tool. The main strategies
to build the software product line are based on the domain commonality and variability, the incremental scope and the
use of existing artifacts. It consists on a lean methodology with little impact on the organization, suitable for small
projects, which reduces product line start-up time.
Software Product Lines focuses on creating a family of products instead of individual products. This approach has
spectacular benefits on reducing the time to market, maintaining the know-how, reducing the development costs and
increasing the quality of new products. The maintenance of the products is also enhanced since all the data acquisition
systems share the same product line architecture.
OSIRIS (Optical System for Imaging and low/intermediate-Resolution Integrated Spectroscopy) and EMIR (InfraRed MultiObject Spectrograph) are instruments designed to obtain images and low resolution spectra of astronomical objects in the optical and infrared domains. They will be installed on Day One and Day Two, respectively, in the Nasmyth focus of the 10-meter Spanish GTC Telescope. This paper describes the architecture of the Data Acquisition System (DAS), emphasizing the functional and quality attributes. The DAS is a component oriented, concurrent, distributed and real time system which coordinates several activities: acquisition of images coming from the detectors controller, tagging, and data communication with the required telescope system resources. This architecture will minimize efforts in the development of future DAS. Common aspects, such as the data process flow, concurrency, asynchronous/synchronous communication, memory management, and exception handling, among others, are managed by the proposed architecture. This system also allows a straightforward inclusion of variable parts, such as dedicated hardware and different acquisition modes. The DAS has been developed using an object oriented approach and uses the Adaptive Communication Environment (ACE) to be operating system independent.
In this contribution we review the overall features of EMIR, the NIR multiobject spectrograph of the GTC. EMIR is at present in the middle of the PD phase and will be one of the first common user instruments for the GTC, the 10 meter telescope under construction by GRANTECAN at the Roque de los Muchachos Observatory (Canary Islands, Spain). EMIR is being built by a Consortium of Spanish, French and British institutes led by the IAC. EMIR is designed to realize one of the central goals of 10m class telescopes, allowing observers to obtain spectra for large numbers of faint sources in an time-efficient manner. EMIR is primarily designed to be operated as a MOS in the K band, but offers a wide range of observing modes, including imaging and spectroscopy, both long slit and multiobject, in the wavelength range 0.9 to 2.5 μm. The present status of development, expected performances and schedule are described and discussed. This project is funded by GRANTECAN and the Plan Nacional de Astronomía y Astrofísica (National Plan for Astronomy and Astrophysics, Spain).
OSIRIS (Optical System for Imaging and low Resolution Integrated Spectroscopy) is the optical Day One instrument for the 10.4m Spanish telescope GTC to be installed in the Observatorio del Roque de Los Muchachos (La Palma, Spain). This instrument, operational in mid-2004, covers from 360 up to 1000 nm. OSIRIS observing modes include direct imaging with tunable and conventional filters, long slit and multiple object spectroscopy and fast spectrophotometry. The OSIRIS wide field of view, high efficiency and the new observing modes (tunable imaging and fast spectrophotometry) for 8-10m class telescopes will provide GTC with a powerful tool for their scientific exploitation. The present paper provides an updated overview of the instrument development, of some of the scientific projects that will be tackled with OSIRIS and of the general requirements driving the optical and mechanical design.
EMIR (Espectrógrafo Multiobjeto Infrarrojo) is a wide-field, near-infrared, multi-object spectrograph, with image capabilities, which will be located at the Nasmyth focus of GTC (Gran Telescopio Canarias). It will allow observers to obtain many intermediate resolution spectra simultaneously, in the nIR bands Z, J, H, K. A multi-slit mask unit will be used for target acquisition.
This paper shows an overview of the EMIR software. Its architecture is distributed with real time features, having in mind to build a reusable, maintainable and inexpensive system. In this paper, we outline the main performances of the current design and some examples already implemented are given.
OSIRIS (Optical System for Imaging and low/intermediate-Resolution Integrated Spectroscopy) is an instrument designed to obtain images and low resolution spectra of astronomical objects in the optical domain (from 365 through 1000nm). It will be installed on Day One (middle of 2004) in the Nasmyth focus of the 10-meter Spanish GTC Telescope. This paper shows an overview of the OSIRIS instrument software. Its architecture is distributed with real time features, having in mind to build a reusable, maintainable and inexpensive system. In this paper, we outline the main performances of the current design and some examples already implemented are given.
EMIR is a multiobject intermediate resolution near infrared (1.0 - 2.5 microns) spectrograph with image capabilities to be mounted on the Gran Telescopio Canarias (Observatorio del Roque de los Muchachos, La Palma, Spain). EMIR is under design by a consortium of Spanish, French and British institutions, led by the Instituto de Astrofisica de Canarias. This work has been partially funded by the GTC Project Office. The instrument will deliver images and spectra in a large FOV (6 X 6 arcmin), and because of the telescope image scale (1 arcmin equals 52 mm) and the spectral resolution required, around 4000, one of the major challenges of the instrument is the optics and optomechanics. Different approaches have been studied since the initial proposal, trying to control the risks of the instrument, while fitting the initial scientific requirements. Issues on optical concepts, material availability, temperature as well as optomechanical mounting of the instrument will be presented.
EMIR is a near-IR, multi-slit camera-spectrograph under development for the 10m GTC on La Palma. It will deliver up to 45 independent R equals 3500-4000 spectra of sources over a field of view of 6 feet by 3 feet, and allow NIR imaging over a 6 foot by 6 foot FOV, with spatial sampling of 0.175 inch/pixel. The prime science goal of the instrument is to open K-band, wide field multi-object spectroscopy on 10m class telescopes. Science applications range from the study of star-forming galaxies beyond z equals 2, to observations of substellar objects and dust-enshrouded star formation regions. Main technological challenges include the large optics, the mechanical and thermal stability and the need to implement a mask exchange mechanism that does not require warming up the spectrograph. EMIR is begin developed by the Instituto de Astrofisica de Canarias, the Instituto Nacional de Tecnica Aeroespacial, the Universidad Complutense de Madrid, the Observatoire Midi-Pyrennees, and the University of Durham. Currently in its Preliminary Design phase, EMIR is expected to start science operation in 2004.