The Observatorio Astrofísico de Javalambre (OAJ) is a new astronomical facility located at the Sierra de Javalambre (Teruel, Spain) whose primary role will be to conduct all-sky astronomical surveys with two unprecedented telescopes of unusually large fields of view: the JST/T250, a 2.55m telescope of 3deg field of view, and the JAST/T80, an 83cm telescope of 2deg field of view. CEFCA engineering team has been designing the OAJ control system as a global concept to manage, monitor, control and maintain all the observatory systems including not only astronomical subsystems but also infrastructure and other facilities. In order to provide quality, reliability and efficiency, the OAJ control system (OCS) design is based on CIA (Control Integrated Architecture) and OEE (Overall Equipment Effectiveness) as a key to improve day and night operation processes. The OCS goes from low level hardware layer including IOs connected directly to sensors and actuators deployed around the whole observatory systems, including telescopes and astronomical instrumentation, up to the high level software layer as a tool to perform efficiently observatory operations. We will give an overview of the OAJ control system design and implementation from an engineering point of view, giving details of the design criteria, technology, architecture, standards, functional blocks, model structure, development, deployment, goals, report about the actual status and next steps.
We have been testing at laboratory commercial variable attenuators commonly used in telecommunication applications
for their used in astronomy. Such variable attenuators are going to be included in the central fibers
of the integral field unit (IFU) of the prototype instrument EDiFiSE (Equalized and Diffraction-limited Field
Spectrograph Experiment). The EDiFiSE IFU is conformed by a lenslet array of 331 lenses, 331 fibers and seven
variable attenuators (inserted in the seven central fibers of the bundle). We present here the characterization of
the attenuator devices tested for their use in astronomy and, in particular, to their application in the observation
of object of large dynamic range using equalized integral field spectroscopy. We also present the optical tests we
have carried out to characterize the performances of two lenslet arrays acquired in the framework of the EDiFiSE
project.
We present EDiFiSE, a prototype instrument for the observation of high-contrast systems, combining an adaptive
optics (AO) system and an equalized integral field unit (EIFU). The design of the AO system takes into account
the statistical behaviour of the atmospheric turbulence structure at the Canary Islands (Spain) astronomical
observatories: Roque de los Muchachos (ORM) on the island of La Palma and Teide observatory (OT) in
Tenerife. The AO will have the capability of adapting to the prevailing turbulence conditions; in this sense,
the EDiFiSE AO unit will be an 'adaptable' adaptive optics system. The corrected beam feeds an hexagonal
integral field unit formed by 331 micro-lenslets, which focus the intensity distribution at the focal plane into 331
optical fibers. The central seven fibers of the bundle include variable attenuators for the equalization of these
fibers output intensities, matching them to the dynamical range of the detector and reducing the optical cross
talk inside the spectrograph. This technique, called equalized integral field spectroscopy (Arribas, Mediavilla &
Fuensalida 19981), permits to obtain spectral and spatial information of the equalized object and its surroundings
as well as accurate relative photometry and astrometry.
We present in this paper the new cute-SCIDAR instrument, entirely developed by the Instituto de Astrofísica de Canarias
(IAC), delivered recently at the European Southern Observatory (ESO) Paranal Observatory (Chile). This instrument,
supported by the European Community (Framework Programme 6, Extremely Large Telescope Design Study), carries
out the generalized SCIntillation Detection And Ranging (g-SCIDAR) technique to obtain the temporal evolution of
turbulence profiles CN
2 with height. A new design was made in order to fit the VLT Auxiliary Telescopes (ATs)
interfaces and control requirements. Also, a new software architecture allows a full remote control, and a data analysis
pipeline provides turbulence profiles in real-time, which is the main achievement of this new cute-SCIDAR. Details of
its design and results of its excellent performance are included.
We have built a hybrid turbulence profiler measuring simultaneously the atmospheric turbulence structure with a Shack-
Hartmann wave front sensor and a G-SCIDAR (scintillation sensor). This is the first instrument combining two different
techniques to measure simultaneously the turbulence structure. The hybrid profiler has been installed at the Carlos
Sánchez Telescope (TCS) at the Teide Observatory (OT), in Tenerife Spain. The G-SCIDAR arm is already working
properly and we are still testing the Shack-Hartmann arm.
In order to characterized the vertical atmospheric structure at the Teide Observatory (Tenerife, Spain), we are
using two different remote sensing technics: SODAR (SOund Detection And Ranging) and SCIDAR (SCIncitillation
Detection And Ranging) at this astronomical site. We present in this work the preliminar results on the
comparison of the simultaneous data from four consecutive nights in March 2007 using both technics. We have
analized the SCIDAR C2N
profiles as well as an estimation of the structure constante of temperature function,C2T,
provided by SODAR. Such C2T
were compared to the simultaneous C2N
profiles from SCIDAR, determining
a calibration factor between the measurements provided by SCIDAR and SODAR. As it was expected, our
preliminary results indicate that this calibration factor is very sensitive to the variations of weather conditions.
The characterization of the vertical turbulence distribution on an astronomical site should be based on statistical
behaviour, as it is required for other parameters in site testing. We present the statistical results of the optical-turbulence
profiles at the Roque de los Muchachos and Teide observatories at the Canary Islands (Spain). The
data were obtained using the generalized scintillation detection and ranging technique at the 1m Jacobus Kapteyn
Telescope and 1.5m Carlos Sánchez Telescope. Statistical results are based on 68 nights in 2004 and 38 nights
in 2005 of measurements at the Roque de los Muchachos observatory (La Palma) and 27 nights of observations
at Teide Observatory (23 in 2004 and 4 in 2005). Statistically, most of the turbulence is concentrated close
the ground level (2400 m above sea level) with no more than two relative intense turbulent layers at higher
altitudes. The temporal evolution of the monthly statistical turbulence profiles indicates that the turbulence is
concentrated at low altitude layers in winter.
In the planning stage of extremely large telescopes, site testing and study of high performance adaptive optics systems plays very important roles. Site testing is a very time consuming task, therefore, we have built a fully automatic device - the CUTE SCIDAR instrument with a user-friendly interface and real time processing. This instrument is already in operation and now has been installed in the Jacobus Kapteyn Telescope of Roque de los Muchachos Observatory at La Palma for periodical turbulence profiling.
A second version with an additional phase sensor bench contains a motorized field stop, a field lens, a collimator lens, and a Shack-Hartmann sensor. This instrument measures the turbulence from both amplitude and phase variations of the same distorted wave at high frequency bandwidth, with a high resolution and dynamic range. On the one hand, this will solve the calibration problem between different turbulence sensors. On the other hand, it allows investigating the performance of multi-conjugated wavefront sensing using real time information from SCIDAR data and proving validity of the near field assumption. From preliminary Shack-Hartmann measurements we conclude that the instrument should be flexible to change optical layout and detection parameters according to the turbulence conditions. Therefore, the phase sensor branch includes automatically controlled moveable devices, and in the future, fast communication facilities between control computers of both SCIDAR and wavefront sensing are previewed. In this paper, we will present our objectives of building such an instrument, give a detailed state of art design, and considerate the preparation of first observational campaigns, that are the first scientific tasks to do.
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