KEYWORDS: Data mining, Control software, Signal processing, Reliability, Telescopes, Software development, Machine learning, Control systems, Analytical research, Software validation
The Square Kilometre Array (SKA) is a groundbreaking radio telescope project, aiming at constructing the two biggest radio telescopes in Australia and South Africa. They will have a larger collecting area and sky resolution than existing radiotelescopes, and they will handle an unprecedented amount of data flowing between computing facilities. The functionality of these telescopes heavily depends on the quality of the operating software. The project’s magnitude and complexity require effective testing processes capable of preemptively identifying and addressing potential bugs and errors. In this context, a simple regression testing strategy is not enough. In the first years of SKA construction, we noticed that tests, which typically pass, may occasionally experience failures. Collecting and analyzing test results over extended time periods could help in understanding the origin of such failures and to find solutions that address them. It would be a significant step forward to improve the reliability of SKA software. Data mining is a process of discovering patterns, trends, correlations, or useful information from large sets of data. It can be applied to a large set of test results concerning the operations of a specific SKA software component, i.e. the Local Monitoring and Control of Central Signal Processor (CSP.LMC). The CSP.LMC is tested with a multilevel strategy, spawning from unit to system tests, that can be performed on different environments. In this paper we analyze the strengths of this approach, describe some of the pitfalls in implementing it, and discuss the possibility to apply it to different SKA Software components.
The Square Kilometer Array (SKA) is devoted to the construction of a two body giant Radio-telescope. The design and implementation of the SKA Monitor and Control software involves about 100 people referring to eight Agile Teams developing different software elements of the telescope. Each of these elements is implemented as a 'device' within the TANGO Control System framework, written in Python code. This paper analyzes the implemented design of the Local Monitoring and Control (LMC) of the Central Signal Processor (CSP), from now on called CSP.LMC. CSP is the SKA element that will make the data that comes from the antennas available for scientific analysis. It is composed of different data processing components, i.e. the Correlator and Beam Former, the Pulsar Search and the Pulsar Timing. In this larger system, CSP.LMC has the role to communicate with the Telescope Manager (TM), i. e. the software front-end for operations, as if the CSP was an unique entity. The paper shows the detailed structure of the software, implemented with an Object Oriented approach, with a design largely inspired by some standard design patterns, such as the Observer, the Command and the Aggregator. Another essential feature is the separation of the business logic from the TANGO communication layer, improving the testability and the maintainability of the code.
SHARK-NIR in an instrument that will provide direct imaging, coronagraphic imaging, dual band imaging and low resolution spectroscopy in Y, J and H bands, and it will be soon installed at the Large Binocular Telescope. Used in combination with SHARK-VIS (operating in V band) and LMIRCam of LBTI (operating from K to M bands), SHARKNIR will exploit coronagraphic simultaneous observations in three different wavelengths. Exoplanets search and characterization, young stellar systems, jets and disks are the main science cases, but the extreme performance of the LBT AO systems, above all in the faint end regime, will allow to open to science difficult to be achieved from other similar instruments, such as AGN and QSO morphological studies. A variety of coronagraphic techniques have been implemented, as the Gaussian Lyot, Shaped Pupil and Four Quadrant masks, with the aim to possibly have a suitable coronagraphic masks for each science case, since the coronagraphic requirement in term of contrast and inner and outer working angle are depending on the target and on the science to be achieved. We report here about the SHARK-NIR status, that should be installed at LBT in mid-2021
Exo-Planets search and characterization has been the science case driving the SHARK-NIR design, which is one of the two coronagraphic instruments proposed for the Large Binocular Telescope. In fact, together with SHARK-VIS (working in the visible domain), it will offer the possibility to do binocular observations combining direct imaging, coronagraphic imaging and coronagraphic low resolution spectroscopy in a wide wavelength domain, going from 0.5μm to 1.7μm. Additionally, the contemporary usage of LMIRCam, the coronagraphic LBTI NIR camera, working from K to L band, will extend even more the covered wavelength range. The instrument has been designed with two intermediate pupil planes and three focal planes, in order to give the possibility to implement a certain number of coronagraphic techniques, with the purpose to select a few of them matching as much as possible the requirements of the different science cases in terms of contrast at various distances from the star and in term of required field of view. SHARK-NIR has been approved by the LBT board in June 2017, and the procurement phase started just after. We report here about the project status, which is currently at the beginning of the AIV phase at INAF-Padova, and should last about one year. Even if exo-planets is the main science case, the SOUL upgrade of the LBT AO will increase the instrument performance in the faint end regime, allowing to do galactic (jets and disks) and extra-galactic (AGN and QSO) science on a relatively wide sample of targets, normally not reachable in other similar facilities.
GIANO-B is the high resolution near-infrared (NIR) spectrograph of the Telescopio Nazionale Galileo (TNG), which started its regular operations in October 2017. Here we present GIANO-B Online Data Reduction Software (DRS) operating at the Telescope.
GIANO-B Online DRS is a complete end-to-end solution for the spectrograph real-time data handling. The Online DRS provides management, processing and archival of GIANO-B scientific and calibration data. Once the instrument control software acquires the exposure ramp segments from the detector, the DRS ensures the complete data flow until the final data products are ingested into the science archive. A part of the Online DRS is GOFIO software, which performs the reduction process from ramp-processed 2D spectra to extracted and calibrated 1D spectra.
A User Interface (UI) developed as a part of the Online DRS provides basic information on the final reduced data, thus allowing the observer to take decisions in real-time during the night and adjust the observational strategy as needed.
KEYWORDS: Calibration, Lamps, Sensors, Spectrographs, Signal to noise ratio, Infrared radiation, Spectroscopy, Signal detection, Data processing, Near infrared spectroscopy
The NIR echelle spectrograph GIANO-B at the Telescopio Nazionale Galileo is equipped with a fully automated online DRS: part of this pipeline is the GOFIO reduction software, that processes all the observed data, from the calibrations to the nodding or stare images. GOFIO reduction process includes bad pixel and cosmic removal, flat-field and blaze correction, optimal extraction, wavelength calibration, nodding or stare group processing. An offline version of GOFIO will allow the users to adapt the reduction to their needs, and to compute the radial velocity using telluric lines as a reference system. GIANO-B may be used simultaneously with HARPS-N in the GIARPS observing mode to obtain high-resolution spectra in a wide wavelength range (383-2450 nm) with a single acquisition. In this framework, GOFIO, as part of the online DRS, provides fast and reliable data reduction during the night, in order to compare the infrared and visible observations on the fly.
GIARPS (GIAno and haRPS) is a project devoted to have on the same focal station of the Telescopio Nazionale Galileo (TNG) both high resolution spectrographs, HARPS–N (VIS) and GIANO–B (NIR), working simultaneously. This could be considered the first and unique worldwide instrument providing cross-dispersed echelle spectroscopy at a resolution of 50,000 in the NIR range and 115,000 in the VIS and over in a wide spectral range (0.383−2.45 μm) in a single exposure. The science case is very broad, given the versatility of such an instrument and its large wavelength range. A number of outstanding science cases encompassing mainly extra-solar planet science starting from rocky planets search and hot Jupiters to atmosphere characterization can be considered. Furthermore both instruments can measure high precision radial velocities by means the simultaneous thorium technique (HARPS–N) and absorbing cell technique (GIANO–B) in a single exposure. Other science cases are also possible. GIARPS, as a brand new observing mode of the TNG started after the moving of GIANO–A (fiber fed spectrograph) from Nasmyth–A to Nasmyth–B where it was re–born as GIANO–B (no more fiber feed spectrograph). The official Commissioning finished on March 2017 and then it was offered to the community. Despite the work is not finished yet. In this paper we describe the preliminary scientific results obtained with GIANO–B and GIARPS observing mode with data taken during commissioning and first open time observations.
SHARK-NIR channel is one of the two coronagraphic instruments proposed for the Large Binocular Telescope, in the framework of the call for second generation instruments, issued in 2014. Together with the SHARK-VIS channel, it will offer a few observing modes (direct imaging, coronagraphic imaging and coronagraphic low resolution spectroscopy) covering a wide wavelength domain, going from 0.5μm to 1.7μm.
Initially proposed as an instrument covering also the K-band, the current design foresees a camera working from Y to H bands, exploiting in this way the synergy with other LBT instruments such as LBTI, which is actually covering wavelengths greater than L' band, and it will be soon upgraded to work also in K band. SHARK-NIR has been undergoing the conceptual design review at the end of 2015 and it has been approved to proceed to the final design phase, receiving the green light for successive construction and installation at LBT.
The current design is significantly more flexible than the previous one, having an additional intermediate pupil plane that will allow the usage of coronagraphic techniques very efficient in term of contrast and vicinity to the star, increasing the instrument coronagraphic performance. The latter is necessary to properly exploit the search of giant exo-planets, which is the main science case and the driver for the technical choices of SHARK-NIR. We also emphasize that the LBT AO SOUL upgrade will further improve the AO performance, making possible to extend the exo-planet search to target fainter than normally achieved by other 8-m class telescopes, and opening in this way to other very interesting scientific scenarios, such as the characterization of AGN and Quasars (normally too faint to be observed) and increasing considerably the sample of disks and jets to be studied.
Finally, we emphasize that SHARK-NIR will offer XAO direct imaging capability on a FoV of about 15"x15", and a simple coronagraphic spectroscopic mode offering spectral resolution ranging from few hundreds to few thousands. This article presents the current instrument design, together with the milestones for its installation at LBT.
The Square Kilometer Array (SKA) project is an international effort to build the world's largest radio telescope, with eventually over a square kilometer of collecting area. For SKA Phase 1, Australia will host the low-frequency instrument with more than 500 stations, each containing around 250 individual antennas, whilst South Africa will host an array of close to 200 dishes. The scale of the SKA represents a huge leap forward in both engineering and research and development towards building and delivering a unique instrument, with the detailed design and preparation now well under way. As one of the largest scientific endeavors in history, the SKA will brings together close to 100 organizations from 20 countries. Every aspect of the design and development of such a large and complex instrument requires state-of-the-art technology and innovative approach. This poster (or paper) addresses some aspects of the SKA monitor and control system, and in particular describes the development and test results of the CSP Local Monitoring and Control prototype. At the SKA workshop held in April 2015, the SKA monitor and control community has chosen TANGO Control System as a framework, for the implementation of the SKA monitor and control. This decision will have a large impact on Monitor an Control development of SKA. As work is on the way to incorporate TANGO Control System in SKA is in progress, we started to development a prototype for the SKA Central Signal Processor to mitigate the associated risks. In particular we now have developed a uniform class schema proposal for the sub-Element systems of the SKA-CSP.
This article presents a proposal aimed at investigating the technical feasibility and the scientific capabilities of high
contrast cameras to be implemented at LBT. Such an instrument will fully exploit the unique LBT capabilities in
Adaptive Optics (AO) as demonstrated by the First Light Adaptive Optics (FLAO) system, which is obtaining excellent
results in terms of performance and reliability. The aim of this proposal is to show the scientific interest of such a
project, together with a conceptual opto-mechanical study which shows its technical feasibility, taking advantage of the
already existing AO systems, which are delivering the highest Strehl experienced in nowadays existing telescopes.
Two channels are foreseen for SHARK, a near infrared channel (2.5-0.9 um) and a visible one (0.9 – 0.6 um), both
providing imaging and coronagraphic modes. The visible channel is equipped with a very fast and low noise detector
running at 1.0 kfps and an IFU spectroscopic port to provide low and medium resolution spectra of 1.5 x 1.5 arcsec
fields.
The search of extra solar giant planets is the main science case and the driver for the technical choices of SHARK, but
leaving room for several other interesting scientific topics, which will be briefly depicted here.
Giano is a Cryogenic Spectrograph located in T.N.G. (Spain) and commissioned in 2013. It works in the range 950-2500
nm with a resolving power of 50000.
This instrument was designed and built for direct feeding from the telescope [2]. However, due to constraints imposed on
the telescope interfacing during the pre-commissioning phase, it had to be positioned on the rotating building, far from
the telescope focus. Therefore, a new interface to the telescope, based on IR-transmitting ZBLAN fibers with 85μm core,
was developed. Originally designed to work directly at the f/11 nasmyth focus of the telescope, in 2011 it has decided to
use a fiber to feed it.
The beam from the telescope is focused on a double fiber boundle by a Preslit Optical Bench attached to the Nasmith A
interface of the telescope. This Optical Bench contains the fiber feeding system and other important features as a guiding
system, a fiber viewer, a fiber feed calibration lamp and a nodding facility between the two fibers. The use of two fibers
allow us to have in the echellogram two spectrograms side by side in the same acquisition: one of the star and the other
of the sky or simultaneously to have the star and a calibration lamp. Before entering the cryostat the light from the fiber
is collected by a second Preslit Optical Bench attached directly to the Giano cryostat: on this bench the correct f-number
to illuminate the cold stop is generated and on the same bench is placed an image slicer to increase the efficiency of the
system.
KEYWORDS: Electromagnetic coupling, Space telescopes, Algorithm development, Radio telescopes, Telescopes, Data processing, Phased arrays, Parallel computing, Signal processing, Data integration
One of the key scientific projects of the SKA radio telescope is a large survey for pulsars both in isolated and
binary systems. The data rate of the pulsar search engine is expected to reach 0.6TeraSamples/sec. For the
purposes of extracting hidden pulses from these streams, we need a complex search strategy which allows us
to explore a three dimensional parameter space and it requires approximately 10PetaFlops. This problem is
well suited for a parallel computing engine, but the dimensions of SKA bring this problem to a new level of
complexity. An up-to-date study shows that this operation would require more than 2000 GPUs. In this report
we will present possible mitigation strategies.
KEYWORDS: Sensors, Telescopes, Near infrared, Control systems, Observatories, Astronomy, Signal detection, Interference (communication), Stars, Spectrographs
ARNICA and LonGSp are two NICMOS based near infrared instruments developed in the 90's by the Astrophysical Observatory of Arcetri. After more than 10 years from decommissioning we refurbished the two instruments
with a new read-out electronics and control software. We present the performances of the refurbished systems
and compare them with the historic behavior. Both instruments are currently used for testing purposes in the
Lab and at the telescope, we present some example applications.
GIANO is the high resolution near IR spectrograph recently commissioned at the 3.58m Telescopio Nazionale Galileo in
La Palma (Spain). GIANO is the first worldwide instrument providing cross-dispersed echelle spectroscopy at a
resolution of 50,000 over the 0.95 – 2.45 micron spectral range in a single exposure. There are outstanding science cases
in the research fields of exo-planets, Galactic stars and stellar populations that could strongly benefit from GIANO
observations down to a magnitude limit comparable to that of 2MASS. The instrument includes a fully cryogenic
spectrograph and an innovative fiber system transmitting out to the K band. It also represents a formidable laboratory to
test performances and prototype solutions for the next generation of high resolution near IR spectrographs at the ELTs.
First results from sky tests at the telescope and science verification occurred between July 2012 and October 2013 will
be presented.
E. Oliva, L. Origlia, R. Maiolino, C. Baffa, V. Biliotti, P. Bruno, G. Falcini, V. Gavriousev, F. Ghinassi, E. Giani, M. Gonzalez, F. Leone, M. Lodi, F. Massi, I. Mochi, P. Montegriffo, M. Pedani, E. Rossetti, S. Scuderi, M. Sozzi, A. Tozzi
GIANO is a high resolution (R50,000) IR spectrograph which provides a quasi-complete coverage of the 0.95-
2.5μm wavelengths range in a single exposure. The instrument was integrated and tested in Arcetri-INAF
(Florence, Italy) and will be commisioned at the 3.58m TNG Italian telescope in La Palma. The major scientific goals include the search for rocky planets with habitable conditions around low-mass stars, quantitative spectroscopy of brown dwarfs, accurate chemical abundances of high metallicity stars and stellar clusters. This presentation describes the status of the instrument and presents the first results obtained in laboratory during the acceptance tests.
GIANO is a high resolution (R≃50,000) cryogenic IR spectrograph covering the 0.95-2.5μm wavelengths range.
It is equipped with a Hawaii-II PACE array. We present the main results and performances of the detector and
acquisition system. We also describe a few special features which have been developed to optimize the noise
performances and minimize spurious effects intrinsic to the detector, such as reset anomaly, cross-talking and
radioactive-like events.
Giano is a high resolution (R'50,000) infrared spectrograph with a near-complete coverage of the 0.95-2.5 microns
wavelengths range. It was assembled in Arcetri-INAF (Florence) and is beeing shipped to the its final destination
at the TNG telescope (La Palma)
We present our measurements of internal wavelength stability of Giano spectra. We are using a new approach
which gives both the wavelength and field tilts. We also show the comparison with the usual mono-dimensional
approach.
MOONS is a new conceptual design for a multi-object spectrograph for the ESO Very Large Telescope (VLT)
which will provide the ESO astronomical community with a powerful, unique instrument able to serve a wide
range of Galactic, Extragalactic and Cosmological studies. The instrument foresees 1000 fibers which can be
positioned on a field of view of 500 square-arcmin. The sky-projected diameter of each fiber is at least 1 arcsec
and the wavelengths coverage extends from 0.8 to 1.8 μm.
This paper presents and discusses the design of the spectrometer, a task which is allocated to the Italian National
Institute of Astrophysics (INAF).
The baseline design consists of two identical cryogenic spectrographs. Each instrument collects the light from
over 500 fibers and feeds, through dichroics, 3 spectrometers covering the "I" (0.79-0.94 μm), "YJ" (0.94-1.35
μm) and "H" (1.45-1.81 μm) bands.
The low resolution mode provides a complete spectrum with a resolving power ranging from R'4,000 in the
YJ-band, to R'6,000 in the H-band and R'8,000 in the I-band. A higher resolution mode with R'20,000 is
also included. It simultaneously covers two selected spectral regions within the J and H bands.
An Optical Frequency Comb-based apparatus, to be used as a calibration system of the IR GIANO astronomical spectrograph, is the aim of the Astro-Comb project. We plan to obtain, starting from a comb repetition rate of 100 MHz, a final calibration spectrum of lines equally spaced by 16 GHz over the spectral range from 1 μm to 2 μm. Such a system is able to overcome some limits of the present day calibrators, allowing to complement a high resolution spectrograph, such as GIANO, for precision measurements like the detection of extra-solar rocky planets.
We present the optical and cryo-mechanical solutions for the Spectrograph of VSI (VLTI Spectro-Imager), the second
generation near-infrared (J, H and K bands) interferometric instrument for the VLTI. The peculiarity of this spectrograph
is represented by the Integrated Optics (IO) beam-combiner, a small and delicate component which is located inside the
cryostat and makes VSI capable to coherently combine 4, 6 or even 8 telescopes. The optics have been specifically
designed to match the IO combiner output with the IR detector still preserving the needed spatial and spectral sampling,
as well as the required fringe spacing. A compact device that allows us to interchange spectral resolutions (from R=200
to R=12000), is also presented.
GIANO-TNG is a cryogenic high resolution infrared spectrometer whose optics include large aspheric mirrors
and cross-dispersing prisms mounted over a ≃1.5 m2 aluminum bench. To achieve the highest possible spectral
stability and repeatability the bench is internally filled with liquid nitrogen whose boil-off pressure is actively
controlled and stabilized to a fraction of mbar. The bench is isostatically mounted inside a ≃2.5 m3 cryostat.
We present the characteristics and performances of the cryogenic system of GIANO which include, in particular,
a temperature uniformity and long-term stability of a few mK and a remarkably low consumption of liquid
nitrogen (less than 1 liter/hr).
There are many ways to achieve the positioning accuracy established from tolerance in a cryogenic environment. One method is an opto-mechanical design which stays aligned at room temperature and at liquid nitrogen temperature without modifications. This could be achieved using aluminium mirrors with thermally matched aluminium holders and optical bench, that isotropically contract at cryogenic temperatures.
The design of holders should allow some adjustment of the optics positions to correct possible errors in the manufacturing of the optical bench and/or optical holders themselves, without precluding the isotropic contraction during the cooling to the working temperature.
This work illustrates the last prototype of cryogenic mirror-holder developed in our laboratory. The mirror mounting is based on a set of six forces which pull the mirror against the tree orthogonal faces of a reference corner. Adjustments to the mirror alignment can be achieved by means of six aluminium micrometers. Here we describe the device and illustrate the test results.
GIANO is an infrared (0.9-2.5 μm cross-dispersed echelle spectrometer designed to achieve high resolution, high throughput, wide band coverage and very high stability for accurate radial velocity measurements. It also includes polarimetric capabilities and a low resolution mode with RS ~ 400 and complete 0.75-2.5 μm coverage. This makes it a very versatile, common user instrument which will be permanently mounted and available on the Nasmyth-B foci of the Telescopio Nazionale Galileo (TNG) located at Roque de Los Muchachos Observatory (ORM), La Palma, Spain. The project is fast-track and relies on well known, relatively standard technologies. It has been recognized as one of the top priority instrumental projects of INAF (the Italian National Institute of Astronomy) and received its first financing for the phase-A study in October 2003. Integration in the laboratory is planned to start before the end of 2006, commissioning at the telescope is foreseen within 2007 and scientific operations in 2008. One of the most important scientific goals is the search for rocky planets with habitable conditions around low-mass stars. If completed on time, GIANO will be the first and only IR instrument operating worldwide
providing the combination of efficiency, spectral resolution, wavelength coverage and stability necessary for this type of research. With its unique combination of high and low resolution modes, GIANO will also be a very flexible common-user instrument ideal e.g. for quantitative spectroscopy of brown dwarfs, stars and stellar clusters as well as for the determination of the spectral energy distribution of faint/red objects such as high redshift galaxies. The expected limiting magnitudes are such that GIANO will be able to deliver good quality HR spectra of any 2MASS object and LR spectra of any object detected in the UKIDSS large area survey.
We present the general software design and acquisition facilities of GIANO, an ultra-stable IR echelle spectrometer
optimized both for low (R ≃ 500) and high (R ≃ 50, 000) resolution, that will be mounted at Nasmyth-B focus
of the Telescopio Nazionale Galileo (TNG).
We describe the high-level software structure of the instrument, the user interface characteristics and the control
of all subsystems. The management of GIANO sensors and controls of the mechanical movements is indeed a
crucial issue that is handled by dedicated tasks. Monitoring of all these parameters is performed by means of
separated processes running in background on the control workstation (PC).
In this paper we will also schematically discuss the software for the instrument control, status display and setup,
the quick look facility and the pipeline for data reduction.
Giano is an infrared (0.9-2.5 μm) cross-dispersed echelle spectrometer designed to achieve high throughput, high resolving power, wide band coverage and high accuracy. Giano will be a common user instrument which will be permanently mounted at the Telescopio Nazionale Galileo (TNG), located at Roque de Los Muchachos Observatory (ORM), La Palma, Spain. Giano successfully concluded the development phase, and we present here some of the solutions adopted in the focal plane electronics, which take care of detector control and data acquisition and handling.
GIANO is an infrared (0.9-2.5 μm) cross-dispersed echelle spectrometer designed to achieve high throughput, high resolving power, wide band coverage and high accuracy radial velocity measurements. It also includes polarimetric capabilities and a low resolution mode that make it a very versatile, common user instrument which will be permanently mounted and available at one of the Nasmyth foci of the Telescopio Nazionale Galileo (TNG) located at Roque de Los Muchachos Observatory (ORM), La Palma, Spain. GIANO was selected by INAF as the top priority instrument among those proposed within the Second Generation Instrumentation Plan of the TNG. More information on this project can be found at the web page http://www.bo.astro.it/giano
The paper describes the design of the single conjugate Adaptive Optics system to be installed on the LBT telescope. This system will be located in the Acquisition, Guiding and Wavefront sensor unit (AGW) mounted at the front bent Gregorian focus of LBT. Two innovative key features of this system are the Adaptive Secondary Mirror and the Pyramid Wavefront Sensor. The secondary provides 672 actuators wavefront correction available at the various foci of LBT. Due to the adaptive secondary mirror there is no need to optically conjugate the pupil on the deformable mirror. This allows having a very short sensor optical path made up using small dimension refractive optics. The overall AO system has a transmission of 70 % and fits in a rectangle of about 400×320mm. The pyramid sensor allows having different pupil sampling using on-chip binning of the detector. Main pupil samplings for the LBT system are 30×30, 15×15 and 10×10. Reference star acquisition is obtained moving the wavefront sensor unit in a field of view of 3×2 arcmin. Computer simulations of the overall system performance show the good correction achievable in J, H, and K. In particular, in our configuration, the limiting magnitude of pyramid sensor results more than one magnitude fainter with respect to Shack- Hartmann sensor. This feature directly translates in an increased sky coverage that is, in K band, about doubled with respect to the same AO system using a Shack-Hartmann sensor.
Limiting magnitude of A.O. reference stars is set by wavefront sensor intrinsic noise. Recently available avalanche intensified CCD detectors allow single photon event detection (photon counting) virtually free from readout noise. The paper describes a program started in spring 2002, aiming to use a Marconi L3CCD as a wavefront sensor for A.O.
AMBER is a focal instrument for the Very Large Telescope Interferometer working in the near infrared from 1.1 to 2.4 micrometers . It has been designed having in mind the General User of interferometric observations and the full range of his possible astrophysical programs. However the three programs used to define the key specifications have been the study of Young Stellar Objects, the study of Active Galactic Nuclei dust tori and broad line regions and the measure of masses and spectra of hot Extra Solar Planets. AMBER combines up to three beams produced by the VLTI 8 m Unit Telescopes equipped with Adaptive Optics and/or by the 1.8 m Auxiliary Telescopes. The fringes are dispersed with resolutions ranging from 35 to 10000. It is optimized for high accuracy single mode measurements of the absolute visibility, of the variation of the visibility and phase with wavelength (differential interferometry) and of phase closure relations with three telescopes. The instrument and its software are designed to allow a highly automated user friendly operation and an easy maintenance.
We describe the general characteristics of the TIRGO infrared telescope, located on Gornergrat (Switzerland), and its most recent instrumentation. This telescope is specifically designed for infrared astronomical observations. Two newly designed instruments are presented: the imaging camera Arnica and the long-slit spectrometer LonGSp, both based on two-dimensional array detectors.
ARNICA (ARcetri Near Infrared CAmera) is the imaging camera for the near infrared bands between 1.0 and 2.5 micrometers that Arcetri Observatory has designed and built as a general facility for the TIRGO telescope (1.5 m diameter, f/20) located at Gornergrat (Switzerland). The scale is 1' per pixel, with sky coverage of more than 4' X 4' on the NICMOS 3 (256 X 256 pixels, 40 micrometers side) detector array. The optical path is compact enough to be enclosed in a 25.4 cm diameter dewar; the working temperature is 76 K. The camera is remotely controlled by a 486 PC, connected to the array control electronics via a fiber-optics link. A C-language package, running under MS-DOS on the 486 PC, acquires and stores the frames, and controls the timing of the array. We give an estimate of performance, in terms of sensitivity with an assigned observing time, along with some details on the main parameters of the NICMOS 3 detector.
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