We present a summary of the Large Millimeter Telescope (LMT) Project and its current status. The LMT is a joint project of the University of Massachusetts (UMass) in the USA and the Instituto Nacional de Astrofisica, Optica y Electronica (INAOE) in Mexico to build a 50m-diameter millimeter-wave telescope. The LMT site is at an altitude of 4600 m atop Volcan Sierra Negra, an extinct volcanic peak in the state of Puebla, Mexico, approximately 100 km east of the city of Puebla. Construction of the antenna steel structure has been completed and the antenna drive system has been installed. Fabrication of the reflector surface is underway. The telescope is expected to be completed in 2008.
The Atacama Large Millimeter/submillimeter Array (ALMA) is an international radio telescope under construction in the Atacama Desert of northern Chile. ALMA will be situated on a high-altitude site at 5000 m elevation which provides excellent atmospheric transmission over the instrument wavelength range of 0.3 to 3 mm. ALMA will be comprised of two key observing components - an array of up to sixty-four 12-m diameter antennas arranged in a multiple configurations ranging in size from 0.15 to ~14 km, and a set of four 12-m and twelve 7-m antennas operating in closely-packed configurations ~50m in diameter (known as the Atacama Compact Array, or ACA), providing both interferometric and total-power astronomical information. High-sensitivity dual-polarization 8 GHz-bandwidth spectral-line and continuum measurements between all antennas will be available from two flexible digital correlators. At the shortest planned wavelength and largest configuration, the angular resolution of ALMA will be 0.005". The instrument will use superconducting (SIS) mixers to provide the lowest possible receiver noise contribution, and special-purpose water vapor radiometers to assist in calibration of atmospheric phase distortions. A complex optical fiber network will transmit the digitized astronomical signals from the antennas to the correlators in the Array Operations Site Technical Building, and post-correlation to the lower-altitude Operations Support Facility (OSF) data archive. Array control, and initial construction and maintenance of the instrument, will also take place at the OSF. ALMA Regional Centers in the US, Europe and Japan will provide the scientific portals for the use of ALMA; a call for early science observations is expected in 2009. In this paper, we present the status of the ALMA project as of mid 2006.
Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) is a meridian reflecting Schmidt telescope with
an average clear aperture of 4-meter, a focal length of 20-meter and a field of view of 5-degree. It is a national large
scientific project in China. The horizontal meridian reflecting Schmidt configuration and with an active Schmidt
correcting plate to achieve the special telescope with both wide field of view and large aperture. There are 4000 optical
fibers on the focal surface to transfer light of 4000 objects into 16 spectrographs. The project started in 1997. Now it
steps into its assembly stage. The general status and progress of LAMOST project is presented in this paper: The key
technologies of the project have been tested successfully; the design and manufacturing of the mechanical parts of the
telescope have been completed; most segmented mirrors (sub-mirrors) have been polished. Also the first spectrograph,
the first three sub-mirrors of Ma (Schmidt plate) with their complete support system, and the first three sub-mirror of the
primary mirror are ready for being integrated on the telescope structure
The entire funding has recently been obtained in Belgium for the construction of a 4m Liquid Mirror Telescope. Its prime focus will be equipped with a semi-conventional glass corrector allowing to correct for the TDI effect and a thinned, high quantum efficiency, 4K × 4K pixel equivalent CCD camera. It will be capable of subarcsecond imaging in the i'(760 nm) and possibly r', g' band(s) over a field of ~ 30' in diameter. This facility will be entirely dedicated to a deep photometric and astrometric variability survey over a period of ~ 5 years. In this paper, the working principle of liquid mirror telescopes is first recalled, along with the advantages and disadvantages of the latter over classical telescopes. Several science cases are described. For a good access to one of the galactic poles, the best image quality sites for the ILMT are located either in Northern Chile (latitude near -29°30') or in North-East India (Nainital Hills, latitude near +29°30'). At those geographic latitudes, a deep (i' = 22.5 mag.) survey will approximately cover 90 square degrees at high galactic latitude, which is very useful for gravitational lensing studies as well as for the identification of various classes of interesting galactic and extragalactic objects (cf. microlensed stars, supernovae, clusters, etc.). A description of the telescope, its instrumentation and the handling of the data is also presented.
The Discovery Channel Telescope (DCT) is a 4.2-m telescope being built at a new site near Happy Jack, in northern Arizona. The DCT features a 2-degree-diameter field of view at prime focus and a Ritchey-Chretien (RC) configuration with Cassegrain and Nasmyth focus capability for optical/IR imaging and spectroscopy. Formal groundbreaking at the Happy Jack site for the DCT occurred on 12 July 2005, with construction of major facility elements underway.
LSST will be a large, wide-field groundbased telescope designed to obtain sequential images of the entire visible sky every few nights. The optical design involves a 3-mirror system with an 8.4 m primary, which feeds three refractive correcting elements inside a camera, providing a 10 square degree field of view sampled by a 3 Gpixel focal plane array. The total effective system throughput, AΩ = 319 m2 deg2, is nearly two orders of magnitude larger than that of any existing facility. The survey will yield contiguous overlapping imaging of 20,000 square degrees of sky in 6 optical bands covering the wavelength regime 320-1060 nm.
VISTA is a 4-m wide field survey telescope with a near infra-red camera and a demanding f/1 primary design now well into its manufacturing phase. We contracted out major items, and generated a coordinated approach to the management of engineering budgets through systems engineering, risks through risk management, and safety through the generation of safety cases. Control of the interfaces and science requirements has been maintained and developed through the current phase. The project is developing the commissioning plan to deliver an effective and safe facility. The current status of VISTA is presented as we move towards the on site integration phase.
The GTC (Gran Telescopio Canarias) is a 10,4 meter segmented telescope, whose integration is currently being completed at the ORM in La Palma, Spain. The GTC is a partnership between Spain, Mexico and the University of Florida. Main science drivers for the GTC are image quality, operational efficiency and reliability. First light is planned for late-2006. The GTC Project, initiated in 1996, is nearly complete in its integration. Groundbreaking was done in 2000. The telescope building and dome were finished by end 2002. The telescope structure was complete in early 2005. Since then this structure is being completed with the rest of the parts, i.e. M1 mirror subcells, M3 tower, main axes encoders and motors, cables, pipes and cable-rotators, electronic cabinets, etc. The mirrors will be installed at the telescope, just before First Light. All the optical elements have been finished and are being prepared to be installed. Three science instruments are being completed to be installed as first generation instruments. Two second-generation instruments, including one exploiting the future Adaptive Optics capabilities of the GTC, are under development.
The four-meter Advanced Technology Solar Telescope (ATST) will be the most powerful solar telescope and the world's leading resource for studying solar magnetism that controls the solar wind, flares, coronal mass ejections and variability in the Sun's output. Development of a four-meter solar telescope presents many technical challenges (e.g., thermal control of the enclosure, telescope structure and optics). We give a status report of the ATST project (e.g., system design reviews, instrument PDR, Haleakala site environmental impact statement progress) and summarize the design of the major subsystems, including the telescope mount assembly, enclosure, mirror assemblies, wavefront correction, and instrumentation.
The New Solar Telescope (NST) project at Big Bear Solar Observatory (BBSO) now has all major contracts
for design and fabrication in place and construction of components is well underway. NST is a collaboration
between BBSO, the Korean Astronomical Observatory (KAO) and Institute for Astronomy (IfA) at the University
of Hawaii. The project will install a 1.6-meter, off-axis telescope at BBSO, replacing a number of older solar
telescopes. The NST will be located in a recently refurbished dome on the BBSO causeway, which projects
300 meters into the Big Bear Lake. Recent site surveys have confirmed that BBSO is one of the premier solar
observing sites in the world. NST will be uniquely equipped to take advantage of the long periods of excellent
seeing common at the lake site. An up-to-date progress report will be presented including an overview of the
project and details on the current state of the design. The report provides a detailed description of the optical
design, the thermal control of the new dome, the optical support structure, the telescope control systems, active
and adaptive optics systems, and the post-focus instrumentation for high-resolution spectro-polarimetry.
VERITAS (the Very Energetic Radiation Imaging Telescope Array System) is one of a new generation of ground-based gamma-ray observatories. It is being built by a collaboration of ten institutions from Canada, Ireland, the U.K. and the U.S.A. VERITAS uses the imaging atmospheric Cherenkov technique (IACT) which was developed by the Whipple collaboration using the Whipple 10m telescope. The 10m was the first ground-based gamma-ray telescope to detect both galactic and extragalactic sources of TeV gamma rays. VERITAS is designed to operate in the range from 50 GeV to 50 TeV with optimal sensitivity near 200 GeV; it will effectively overlap with the next generation of space-based gamma-ray telescopes.
EOS Technologies has been commissioned to design and build a unique 2.4m astronomical telescope for the Magdalena
Ridge Observatory. This telescope utilizes a high quality primary mirror and cell from a now decommissioned military
application. This paper describes the project and gives an overview of the telescope design.
The Magdalena Ridge Observatory (MRO) 2.4 meter telescope will be primarily utilized to observe, track, and
characterize solar system astronomical targets, Earth satellites, space vehicles, and terrestrial military targets. The
telescope's rapid tracking (slew rates are 10o/sec) will allow it to move to any target and acquire data within one minute
of receipt of notice. In this way, the telescope will be used to capitalize on targets of opportunity that occur in asteroid
studies (e.g., Near Earth Objects) and in astrophysics, such as gamma ray bursts and other transient phenomena. Planned
instrumentation includes a CCD imager, and a low-resolution, wide-band Visible/IR spectrograph (Ryan et al. 2002).
Both of these instruments will facilitate characterization studies of asteroids and space objects.
We present the technical status of the Ultra Lightweight Telescope for Research in Astronomy (ULTRA) program. The program is a 3-year Major Research Instrumentation (MRI) program funded by NSF. The MRI is a collaborative effort involving Composite Mirror Applications, Inc. (CMA), University of Kansas, San Diego State University and Dartmouth College. Objectives are to demonstrate the feasibility of carbon fiber reinforced plastic (CFRP) composite mirror technology for ground-based optical telescopes. CMA is spearheading the development of surface replication techniques to produce the optics, fabricating the 1m glass mandrel, and constructing the optical tube assembly (OTA). Presented will be an overview and status of the 1-m mandrel fabrication, optics development, telescope design and CFRP telescope fabrication by CMA for the ULTRA Telescope.
The SkyMapper wide field telescope is currently in production by EOS and is scheduled for first light in Q1 2007. This telescope will produce high quality images over a 3.4 degree diameter flat field for wavebands from 310 nm to 1000 nm. This paper discusses the optical and opto-mechanical design and tolerancing of the SkyMapper Telescope.
The design for robotic telescopes to observe Gamma-Ray Burst (GRB) afterglows and the results of observations
are presented. Quickly fading bright GRB flashes and afterglows provide a good tool to study an extremely early
universe. However, most large ground-based telescopes cannot afford to follow-up the afterglows and flashes
quickly within a few hours since a GRB explosion. We re-modeled the existing middle-class 1.3 m &slasho; telescope of
the near infrared band at ISAS in Japan to match for the above requirement. We also set a small telescope of
30 cm diameter with a conventional CCD. These telescopes can monitor afterglows quickly within a few minutes
in J, H, Ks and R band with a grism spectrometer.
Ground based gamma-ray telescopes are providing currently key observations to explore the non-thermal universe. The High Energy Stereoscopic System (H.E.S.S.) is a recently commissioned system of four air Cherenkov telescopes observing mainly the southern sky from Namibia at very high energies (VHE) of 100 GeV and above. The data taken during the first two years of operation have unveiled a rich and diverse population of gamma-ray emitters including Pulsar Wind nebulae, the environment of the super-massive black hole in the heart of the Galaxy, shell type supernova remnants, an X-ray binary, so far unidentified Galactic sources, and extragalactic objects mainly of the type of so-called TeV blazars. The extension of H.E.S.S. (Phase II) is already under construction and is scheduled to begin operation in 2007: A large (35 m diameter) Cherenkov telescope is added to the existing 12 m diameter telescopes. The new telescope will extend the energy range towards 20 GeV closing the so far unobserved gap in the energy range between 10 and 100 GeV.
"BOOTES-IR" is the extension of the BOOTES experiment, which has been operating in Southern Spain since
1998, to the near-infrared (nIR). The goal is to follow up the early stage of the gamma ray burst (GRB)
afterglow emission in the nIR, as BOOTES does already at optical wavelengths. The scientific case that drives
the BOOTES-IR performance is the study of GRBs with the support of spacecraft like HETE-2, INTEGRAL and
SWIFT (and GLAST in the future). Given that the afterglow emission in both, the nIR and the optical, in the
instances immediately following a GRB, is extremely bright (reached V = 8.9 in one case), it should be possible
to detect this prompt emission at nIR wavelengths too. Combined observations by BOOTES-IR and BOOTES-1
and BOOTES-2 since 2006 can allow for real time identification of trustworthy candidates to have a ultra-high
redshift (z > 6). It is expected that, few minutes after a GRB, the nIR magnitudes be H ~ 10-15, hence very
high quality spectra can be obtained for objects as far as z = 10 by much larger ground-based telescopes. A
significant fraction of observing time will be available for other scientific projects of interest, objects relatively
bright and variable, like Solar System objects, brown dwarfs, variable stars, planetary nebulae, compact objects
in binary systems and blazars.
As the construction of the Subaru Telescope neared the end and the preparation of the first aluminum coating of the primary mirror on the ground floor of the telescope enclosure was in progress in 1997, dust particles blown into the enclosure became a serious issue. The source of the dust particles was mainly volcano cinder rocks in the immediate vicinity of the dome that were crushed through the construction activities, especially by heavy vehicle traffic around the dome. The mitigation measure proposed was to pave the immediate surrounding of the dome. The Subaru dome has a unique design with the special consideration to the airflow through the structure with a few ventilators for the best seeing condition possible. The heat retained by the pavement that may possibly cause thermals was an immediate concern. We examined several types of pavement materials to solve this problem and decided the most suitable materials and method. As a result, we paved the area using asphalt, and were able to improve seeing performance before midnight observation by painting the surface of pavement area white in 2003.
The New Solar Telescope (NST) is an innovative 1.6-meter, off-axis, open telescope currently being developed and built at the Big Bear Solar Observatory (BBSO). The observatory is situated on a small peninsula in Big Bear Lake, a mountain lake at an altitude of about 2100 m in the San Bernardino Mountains of Southern California. The lake effectively suppresses the boundary layer seeing. Thus, providing consistently very good daytime seeing conditions. BBSO has been identified by the site survey for the Advanced Technology Solar Telescope (ATST) as one of the best sites for solar observations. It is uniquely qualified for long-duration observations requiring high-spatial resolution. This type of observations is typically encountered in solar activity monitoring and space weather forecast. The ATST site survey has collected more than two years of data linking seeing conditions to geographical parameters and local climate. We have integrated these data in a MySQL database and we will use this information in connection with a real-time seeing monitor and weather station to predict the seeing conditions at Big Bear such that scheduling and prioritization of observing programs (e.g., synoptic vs. high-resolution modes) becomes possible.
We present the basic design of the THermal Control System (THCS)
for the 1.6-meter New Solar Telescope (NST) at the Big Bear Solar
Observatory (BBSO), California. The NST is an off-axis Gregorian
telescope with an equatorial mount and an open support structure.
Since the telescope optics is exposed to the air, it is imperative
to control the local/dome seeing, i.e., temperature fluctuations
along the exposed optical path have to be minimized. To accomplish
this, a THCS is implemented to monitor the dome environment and
interact with the louver system of the dome to optimize instrument
performance. In addition, an air knife is used to minimize mirror
seeing. All system components have to communicate with the
Telescope Control System (TCS), a hierarchical system of computers
linking the various aspects of the entire telescope system, e.g.,
the active mirror control, adaptive optics, dome and telescope
tracking, weather station, etc. We will provide an initial
thermal model of the dome environment and first measurements taken
in the recently replaced BBSO dome.
To get the strategy to confirm image qualities of Subaru Telescope, we have obtained the statistics of seeing measured with auto guider images obtained during scientific observations. In addition to this, we started a regular operation of a stationary DIMM at the Subaru Telescope site. From the data of natural seeing measured with the DIMM, we expect to reveal contributions of telescope vibration, inadequate enclosure ventilation, or optical aberrations including deformation of primary mirror by wind load. The stationary DIMM station consists of one 30 cm diameter DIMM, its enclosure, the local control unit and Linux based control PC. We put our DIMM station at the catwalk of the Subaru enclosure at the level of 12-m from the ground, because the high location from the ground can minimize the influence of ground layer. We describe details of our DIMM station and show seeing data obtained since June 2005 and comparison with the seeing obtained with Subaru auto guider images in order to check whether the enclosure of Subaru Telescope may affect the DIMM to measure the seeing.
The U.S. Naval Observatory Robotic Astrometric Telescope (URAT) project aims at a highly accurate (5 mas), ground-based, all-sky survey. Requirements are presented for the optics and telescope for this 0.85 m aperture, 4.5 degree diameter field-of-view, specialized instrument, which are close to the capability of the industry. The history of the design process is presented as well as astrometric performance evaluations of the toleranced, optical design, with expected wavefront errors included.
The Stratospheric Observatory for Infrared Astronomy (SOFIA) is the next generation of airborne astronomical observatories. Funded by the U.S. and German space agencies, SOFIA is scheduled for science flights beginning in late-2008. The observatory consists of a 747-SP modified to accommodate a 2.7-meter telescope with an open port design. Academic and government laboratories spanning both the U.S. and Germany are developing science instruments for SOFIA. Using state-of-the-art technologies, SOFIA will explore the emission of astronomical sources with an unprecedented level of angular resolution (θ[arc-seconds] = 0.1 x wavelength [μm]) and spectral line sensitivity at infrared and sub-millimeter wavelengths. The current status of SOFIA is available from the observatory web site at http://sofia.arc.nasa.gov/ and is updated frequently.
We describe SPIDER, a novel balloon-borne experiment designed to measure the polarization of the Cosmic Microwave Background (CMB) on large angular scales. The primary goal of SPIDER is to detect the faint signature of inflationary gravitational waves in the CMB polarization. The payload consists of six telescopes, each operating in a single frequency band and cooled to 4 K by a common LN/LHe cryostat. The primary optic for each telescope is a 25 cm diameter lens cooled to 4 K. Each telescope feeds an array of antenna coupled, polarization sensitive sub-Kelvin bolometers that covers a 20 degree diameter FOV with diffraction limited resolution. The six focal planes span 70 to 300 GHz in a manner optimized to separate polarized galactic emission from CMB polarization, and together contain over 2300 detectors. Polarization modulation is achieved by rotating a cryogenic half-wave plate in front of the primary optic of each telescope. The cryogenic system is designed for 30 days of operation. Observations will be conducted during the night portions of a mid-latitude, long duration balloon flight which will circumnavigate the globe from Australia. By spinning the payload at 1 rpm with the six telescopes fixed in elevation, SPIDER will map approximately half of the sky at each frequency on each night of the flight.
SUNRISE is an international project for the development, construction, and operation of a balloon-borne solar telescope with an aperture of 1 m, working in the UV/VIS spectral domain. The main scientific goal of SUNRISE is to understand the structure and dynamics of the magnetic field in the atmosphere of the Sun. SUNRISE will provide near diffraction-limited images of the photosphere and chromosphere with an unpredecented resolution down to 35 km on the solar surface at wavelengths around 220 nm. The focal-plane instrumentation consists of a polarization sensitive spectrograph, a Fabry-Perot filter magnetograph, and a phase-diverse filter imager working in the near UV. The first stratospheric long-duration balloon flight of SUNRISE is planned in Summer 2009 from the swedish ESRANGE station. SUNRISE is a joint project of the german Max-Planck-Institut fur Sonnensystemforschung (MPS), Katlenburg-Lindau, with the Kiepenheuer-Institut fur Sonnenphysik (KIS), Freiburg, Germany, the High-Altitude Observatory (HAO), Boulder, USA, the Lockheed-Martin Solar and Astrophysics Lab. (LMSAL), Palo Alto, USA, and the spanish IMaX consortium. In this paper we will present an actual update on the mission and give a brief description of its scientific and technological aspects.
Several commercial telecommunication ventures together with a
well funded US military program make it a likely possibility that an
autonomous, high-altitude, light-than-air (LTA) vehicle which
could maneuver and station-keep for weeks to many months will be a reality in a few
years. Here I outline how this technology could be used to develop a
high-altitude astronomical observing platform which could return
high-resolution optical data rivaling those from space-based
platforms but at a fraction of the cost.
The 2.5 meter (m) effective diameter telescope on SOFIA - the Stratospheric Observatory for Infrared Astronomy - will operate in an open-port cavity which will be closed below operating altitudes by a cavity-door assembly. When
operating, the telescope will view the sky through an aperture defined by an aperture assembly (AA) with a nearly
rectangular opening extending 112 inches (2.84 m) in elevation (roll) and 129 inches (3.27 m) in cross-elevation. The
aperture will be servo-controlled in roll to track the telescope elevation (EL), and the aircraft heading will be adjusted to
maintain the telescope centered on the aperture in cross-elevation (XEL). An upper rigid door (URD) and lower
flexible door (LFD) move with the aperture to minimize the opening into the cavity containing the telescope. This paper
describes basic parameters of the door system, and estimates possible science impacts of its specification, configuration
and planned operation. Topics included are the geometry, expected aerodynamic disturbances, control system, gear life,
influences of radiative and diffraction effects on science instrument performance, testing, operational considerations,
and development status. As designed, the door system is expected not to limit the performance of science instruments or
observatory operational efficiency, but several potential concerns are considered. These include modulation of stray
and diffracted radiation, reliability, and maintainability.
The telescope pointing control of the Stratospheric Observatory for Infrared Astronomy (SOFIA) is achieved during
science observations by an array of sensors including three imagers, gyroscopes and accelerometers. In addition,
throughout alignment and calibration of the telescope assembly, the High-speed Imaging Photometer for Occultation
(HIPO) is used as a reference instrument. A summary of the telescope pointing control concept is given and how HIPO
is used to calibrate the telescope reference systems on the sky. A method is introduced using simple maneuvers to
perform initial alignment of HIPO, the imagers and the gyroscopes by means of single star observations. During the first
on sky testing of the SOFIA telescope, these maneuvers were carried out and the alignment could be improved
iteratively. The corresponding alignment accuracies are identified considering repeated measurements, environmental
and sensor noise. Inertial and non-inertial observations, as well as measurements over the entire operational elevation
range provide additional alignment and sensor performance information. Finally, an overview is presented for future
improvements in alignment.
The integration of the three main silicon carbide mirrors into the new 1.5 m solar telescope GREGOR at Izana on Tenerife, Spain is planned during 2006. We expect first light at the end of 2006. A progress report about integration of the optics and mechanics and planning of the commissioning phase of the telescope and post focus instruments will be presented at the meeting. The GREGOR telescope is build by a consortium of the Kiepenheuer Institut fur Sonnenphysik in Freiburg, the Astrophysikalische Institut Potsdam, the Institut fur Astronomie Gottingen and additional national and international Partners.
In March 2004, the Commissioning Instrument (CI) for the GTC was accepted in the site of The Gran Telescopio Canarias (GTC) located in La Palma Island, Spain. During the GTC integration phase, the CI will be a diagnostic tool for performance verification. The CI features four operation modes-imaging, pupil imaging, Curvature Wave-front sensing (WFS), and high resolution Shack-Hartmann WFS. The imaging mode permits to qualify the GTC image quality. The Pupil Mode permits estimate the GTC stray light. The segments figure, alignment and cophasing verifications are made with both WFS modes. In this work we describe the Commissioning Instrument and show some tests results obtained during the site acceptance process at the GTC site.
The Large Binocular Telescope (LBT) Project is a collaboration between institutions in Arizona, Germany, Italy, Indiana, Minnesota, Ohio and Virginia. The telescope on Mt. Graham in southeastern Arizona uses two 8.4-meter diameter primary mirrors mounted side-by-side to produce a collecting area equivalent to an 11.8-meter circular aperture. A unique feature of LBT is that the light from the two primary mirrors can be combined to produce phased array imaging of an extended field. This coherent imaging along with adaptive optics gives the telescope the diffraction-limited resolution of a 22.65-meter telescope. The first primary mirror was aluminized in April 2005. First light with a single primary mirror and a prime focus imager was achieved in October 2005. We describe here some of the technical challenges met and solved on the way to First Light. The second of two 8.4-meter borosilicate honeycomb primary mirrors has been installed in the telescope in October 2005 and was aluminized in January 2006. Binocular operation with two prime focus cameras is planned for Fall 2006. The telescope uses two F/15 adaptive secondaries to correct atmospheric turbulence. The first of these adaptive mirrors is now being integrated with its electro-mechanics.
The Southern African Large Telescope (SALT) was completed in 2005 and began initial scientific operations in August
of that year. Built in just under 6 years and on budget, SALT has been a good example of a successfully managed
telescope project where systems engineering disciplines have been applied to good effect. This paper discusses the
experiences of completing and commissioning SALT and its first-light instruments and the early scientific operations.
Lessons learned in integrating the various telescope subsystems and implementation of the telescope control system are
presented. First Light was announced on 1 September 2005 following the installation of the last of the 91 mirror
segments and the commissioning of the UV-visible imager, SALTICAM. This was soon followed by the first scientific
observations and the beginning of the commissioning phase for the active optics system.
The Large Binocular Telescope is currently equipped with a couple of wide field Prime Focus. The two cameras are optimized for, respectively, the blue and the red portion of the visible spectrum. The history of this project is here sketched up and the current status is shown. The Blue channel is currently working onboard the telescope and provided what has been named the first-light of the telescope in single eye configuration.
The new German solar 1.5 m telescope (GREGOR) will be equipped with an adaptive optic system. GREGOR has a relatively complicated optical scheme with small tolerances. We therefore have to expect certain aberrations due to misalignments and mechanical/optical imperfections. This is why the AO will play an important role as an auxiliary tool for telescope alignment from the very beginning of the commissioning phase. The paper will cover the alignment strategies taking advantage of the AO system.
The National Radio Astronomy Observatory Green Bank Telescope (GBT) is the world's largest fully steerable
telescope. The GBT has now been in routine operation for over two years, observing at frequencies up to 50 GHz. In
order to deliver the tracking accuracies required at 50 GHz, we solve simultaneously for gravitational and thermal
effects in the development of the static pointing and focus tracking models. A precision temperature sensor system then
generates additional real-time corrections to compensate for varying thermal gradients in the antenna. Collimation and
surface accuracy requirements are met by an active surface control system which combines initial corrections derived
from a finite element model of the antenna with additional terms derived from astronomical phase-retrieval holography
measurements. The GBT has a rich suite of instrumentation including receivers which cover almost the complete
frequency range from ~ 290 MHz to 50 GHz, and backends for spectroscopy, pulsar observing, broadband continuum,
very long baseline interferometry and planetary radar reception. A 64-pixel bolometer camera is under development by
a consortium including UPenn, NASA-GSFC, NIST, UCardiff and NRAO. Recent software developments include an
extremely flexible application which combines traditional interactive observing, scheduling-block based observing and
real-time monitoring and data display in a single, convenient interface. In this paper I will summarize the current
performance of the GBT, and review some recent science results. I will also describe how plans changed with time, and
review some of the lessons learned in the development of the telescope.
The Combined Array for Research in Millimeter-wave Astronomy (CARMA) comprises the millimeter-wave antennas of the Owens Valley Radio Observatory (OVRO), the Berkeley-Illinois-Maryland Association (BIMA) Array, and the new Sunyaev-Zel'dovich Array (SZA). CARMA consists of six 10.4-m, nine 6.1-m, and eventually eight 3.5-m diameter antennas on a site at elevation 2200 m in the Inyo Mountains near Bishop, California. The array will be operated by an association that includes the California Institute of Technology and the Universities of California (Berkeley), Chicago, Illinois (Urbana-Champaign), and Maryland. Observations will be supported at wavelengths of 1 cm, 3 mm, and 1.3 mm, on baselines from 5 m to 2 km. The initial correlator will use field programmable gate array (FPGA) technology to provide all single-polarization cross-correlations on two subarrays of 8 and 15 antennas with a total bandwidth of 8 GHz on the sky. The next generation correlator will correlate the full 23-antenna array in both polarizations. CARMA will support student training, technology development, and front-line astronomical research in a wide range of fields including cosmology, galaxy formation and evolution, star and planet formation, stellar evolution, chemistry of the interstellar medium, and within the Solar System, comets, planets, and the Sun. Commissioning of CARMA began in August 2005, after relocation of the antennas to the new site. The first science observations commenced in April 2006.
APEX, the Atacama Pathfinder Experiment, has been successfully commissioned and is in operation now. This novel submillimeter telescope is located at 5107 m altitude on Llano de Chajnantor in the Chilean High Andes, on what is considered one of the world's outstanding sites for submillimeter astronomy. The primary reflector with 12 m diameter has been carefully adjusted by means of holography. Its surface smoothness of 17-18 μm makes APEX suitable for observations up to 200 μm, through all atmospheric submm windows accessible from the ground.
Science studies made by the Large Synoptic Survey Telescope will reach systematic limits in nearly all cases. Requirements for accurate photometric measurements are particularly challenging. Advantage will be taken of the rapid cadence and pace of the LSST survey to use celestial sources to monitor stability and uniformity of photometric data. A new technique using a tunable laser is being developed to calibrate the wavelength dependence of the total telescope and camera system throughput. Spectroscopic measurements of atmospheric extinction and emission will be made continuously to allow the broad-band optical flux observed in the instrument to be corrected to flux at the top of the atmosphere. Calibrations with celestial sources will be compared to instrumental and atmospheric calibrations.
From 2006 to 2008, all sub-mirrors and instruments of LAMOST will be installed gradually until fully completion. Before all sub-mirrors and instruments installed, LAMOST team planed a temporary scheme in order to do some testing observations. The plan will start from the beginning of 2007, and the part LAMOST will have 3×3 Mirrors (3 sub Ma and 3 sub Mb) with 1.25 degree field, and 250 fibers on its focal plane at that time. We are planning a set of observations during the engineering process, which includes small amount of stars. The spectral resolution will be 10000 and 2000, and the amount of spectra in the data set will reach several thousands. By using these data, we can improve our techniques of automated reduction and analyzing. For example, in order to test our software, physical parameters of a small proportion of stars such as Vr, Teff, log g, [Fe/H], [α/Fe] should be compared with Sloan Digital Sky Survey (SDSS). If the results are precise enough, the parameters of more stars could be applied to do some research, such as searching for star stream, studying star clusters in our Galaxy, and searching for poor-metal star etc.
Dome C, located on the Antarctic Plateau, is expected to be one of the best sites for ground-based astronomical observations at infrared wavelengths. Its high elevation, equivalent to 3800 m of a temperate site, and the very low temperatures (down to -90°C), reduce dramatically the background thermal emission from both the instrument and the sky; the very dry and cold environment makes the atmospheric windows more transparent, wide and stable than in any ground-based temperate site. The Antarctic Multiband Infrared Camera (AMICA), mounted at the focal plane of the IRAIT telescope, is designed to perform astronomical observations at near- and mid-infrared wavelengths from Dome C.
In order to fully exploit the above-mentioned excellent site conditions, a set of optimized infrared filters covering the 2 - 25 microns region has been defined as a result of a careful analysis.
In the first step, the bands of interest were identified on the basis of the scientific requirements and the opportunities offered by the site. The fundamental scientific parameters, as the central wavelength, the bandwidth, the isophotal magnitude were then computed for each filter, in such a way to optimize the camera performances.
In this paper we present the characterization of some of the principal meteorological parameters extended over 25 km from the ground and over two years (2003 and 2004) above the Antarctic site of Dome C. The data set is composed by 'analyses' provided by the General Circulation Model (GCM) of the European Center for Medium Weather Forecasts (ECMWF) and they are part of the catalog MARS. A monthly and seasonal (summer and winter time) statistical analysis of the results is presented. The Richardson number is calculated for each month of the year over 25 km to study the stability/instability of the atmosphere. This permits us to trace a map indicating where and when the optical turbulence has the highest probability to be triggered on the whole troposphere, tropopause and stratosphere. We finally try to predict the best expected isoplanatic angle and wavefront coherence time (θ0,max and a τ0,max) employing the Richardson number maps, the wind speed profiles and simple analytical models of CN2 vertical profiles.
The MMT all-sky camera is a low-cost, wide-angle camera system that takes images of the sky every 10 seconds, day and night. It is based on an Adirondack Video Astronomy StellaCam II video camera and utilizes an auto-iris fish-eye lens to allow safe operation under all lighting conditions, even direct sunlight. This combined with the anti-blooming characteristics of the StellaCam's detector allows useful images to be obtained during sunny days as well as brightly moonlit nights. Under dark skies the system can detect stars as faint as 6th magnitude as well as very thin cirrus and low surface brightness zodiacal features such as gegenschein. The total hardware cost of the system was less than $3500 including computer and framegrabber card, a fraction of the cost of comparable systems utilizing traditional CCD cameras.
The high plateaus in west China (Tibet) may provide good candidate sites possibly for ELT projects. According to satellite weather data, we found that a certain area in Tibet shows potentiality for good astronomical observations with less cloud coverage. We have explored through west Tibet to watch its topography in summer, 2004. We reanalyze meteorological data collected by GAME-Tibet project. We have started weather monitor in two candidate sites in west China; Oma in western area of Tibet and Karasu near the western boundary of China. Monitoring observations using modern astronomical site-testing techniques such as a DIMM and an IR cloud monitor camera will be started to catch up continuous monitoring of seeing and cloud coverage.
The simulation of the optical turbulence (OT) for astronomical applications obtained with non-hydrostatic atmospherical models at meso-scale presents, with respect to measurements, some advantages. Among these: (1) the possibility to provide 3D C2N maps above a region of a few tens of kilometers around a telescope. (2) the possibility to simulate the turbulence 'where' and 'when' it is desired without the need of long and expensive site testing campaigns done with several instruments. (3) the possibility to forecast the optical turbulence, goal considered a 'chimera' by all astronomers and fundamental element for the implementation of the flexible scheduling, crucial operation mode for the success of new class of telescopes (D > 10 m). The future of the ground-based astronomy relies upon the potentialities and feasibility of the ELTs. Our ability in knowing, controlling and 'managing' the effects of the turbulence on such a new generation telescopes and facilities are determinant to assure their competitiveness with respect to the space astronomy. In the past several studies have been carried out proving the feasibility of the simulation of realistic C2N profiles above astronomical sites. The European Community (FP6 Program) decided recently to fund a Project aiming, from one side, to prove the feasibility of the OT forecasts and the ability of meso-scale models in discriminating astronomical sites from optical turbulence point of view and, from the other side, to boost the development of this discipline at the borderline between the astrophysics and the meteorology. In this contribution I will present the scientific and technological goals of this project, the challenges for the ground-based astronomy that are related to the success of such a project and the international synergies that have been joint to optimize the results.
We present a proposal for an 8.4 metre off-axis optical/IR telescope to be located at Dome C, Antarctica. LAPCAT will use a mirror identical to the offset segment recently cast for the Giant Magellan Telescope (GMT) as a completely unobscured f/2.1 primary. With a cooled deformable Gregorian secondary in a dewar following prime focus, LAPCAT will allow for diffraction-limited imaging with only a single reflecting surface at ~220K, and thus the lowest possible thermal background obtainable on earth. The exceptionally low atmospheric turbulence above Dome C enables very high contrast imaging in the thermal infrared, and diffraction limited imaging extending to optical wavelengths (20 mas at 800 nm, where Strehl ratios > 60% are projected). As an example, a deep 5 μm exoplanet imaging survey to complement current radial velocity methods could take advantage of both the low background and pupil remapping methods for apodization enabled by the clear aperture. Many new, young, giant planets (≥ 3MJ at 1 Gyr) would be detected in orbits ≥ 5 AU out to 20 pc. By providing a test bed for many of the GMT technologies in an Antarctic environment, LAPCAT also paves the way for the eventual construction of a second GMT at Dome C. Such a telescope would have unparalleled capabilities compared both to other ELTs in temperate sites and to JWST.
We describe a large-angle survey for fast, optical transients: gamma ray bursts (GRBs), supernovae (SNe), lensed and transiting planets, AGNs and serendipitously found objects. The principal science goals are to obtain light curves for all transients and to obtain redshifts of GRBs and orphan afterglows. The array is called Xian. In conjunction with the gamma-ray satellites, ECLAIRs/SVOM and GLAST, the data will be used to study sources from z=0.1 to >6. The telescope array has 400 Schmidt telescopes, each with ~20 sq. degree focal planes and apertures of ~0.5 meters. The passively cooled, multiple CCD arrays have a total of 16000x16000 pixels, up to 13 readout channels per 1K x 4K CCD and work in TDI mode. The system provides continuous coverage of the circumpolar sky, from the Antarctic plateau, every few seconds. Images averaged over longer time intervals allow searches for the host galaxies of the detected transients, as well as for fainter, longer timescale transients. Complete, data at high time resolution are only stored for selected objects. The telescopes are fixed and use a single filter: there are few (or no) moving parts. Expected detection rates are 0.3 GRBs afterglows per day, >100 orphan afterglows per day and >0.1 blue flashes per day from Type II or Type Ib/c supernovae. On-site computers compare successive images and trigger follow-up observations of selected objects with a co-sited, well-instrumented telescope (optical, IR; spectroscopy, photometry, polarimetry), for rapid follow-up of transients. Precursor arrays with 20-100 square degrees are planned for the purpose of developing trigger software, testing observing strategies and deriving good cost estimates for a full set of telescope units.
Thanks to exceptional coldness, low sky brightness and low content of water vapour of the above atmosphere Dome C,
one of the three highest peaks of the large Antarctic plateau, is likely to be the best site on Earth for thermal infrared
observations (2.3-300 μm) as well as for the far infrared range (30 μm-1mm). IRAIT (International Robotic Antarctic
Infrared Telescope) will be the first European Infrared telescope operating at Dome C. It will be delivered to Antarctica
at the end of 2006, will reach Dome C at the end of 2007 and the first winter-over operation will start in spring 2008.
IRAIT will offer a unique opportunity for astronomers to test and verify the astronomical quality of the site and it will be
a useful test-instrument for a new generation of Antarctic telescopes and focal plane instrumentations. We give here a
general overview of the project and of the logistics and transportation options adopted to facilitate the installation of
IRAIT at Dome C. We summarize the results of the electrical, electronics and networking tests and of the sky
polarization measurements carried out at Dome C during the 2005-2006 summer-campaign. We also present the 25 cm
optical telescope (small-IRAIT project) that will installed at Dome C during the Antarctic summer 2006-2007 and that
will start observations during the 2007 Antarctic winter when a member of the IRAIT collaboration will join the Italian-French Dome C winter-over team.
The Antarctic Plateau offers unique opportunities for ground-based Infrared Astronomy. AMICA (Antarctic Multiband Infrared CAmera) is an instrument designed to perform astronomical imaging from Dome-C in the near- (1 - 5 μm) and mid- (5 - 27 μm) infrared wavelength regions. The camera consists of two channels, equipped with a Raytheon InSb 256 array detector and a DRS MF-128 Si:As IBC array detector, cryocooled at 35 and 7 K respectively. Cryogenic devices will move a filter wheel and a sliding mirror, used to feed alternatively the two detectors. Fast control and readout, synchronized with the chopping secondary mirror of the telescope, will be required because of the large background expected at these wavelengths, especially beyond 10 μm. An environmental control system is needed to ensure the correct start-up, shut-down and housekeeping of the camera. The main technical challenge is represented by the extreme environmental conditions of Dome C (T about -90 °C, p around 640 mbar) and the need for a complete automatization of the overall system. AMICA will be mounted at the Nasmyth focus of the 80 cm IRAIT telescope and will perform survey-mode automatic observations of selected regions of the Southern sky. The first goal will be a direct estimate of the observational quality of this new highly promising site for Infrared Astronomy. In addition, IRAIT, equipped with AMICA, is expected to provide a significant improvement in the knowledge of fundamental astrophysical processes, such as the late stages of stellar evolution (especially AGB and post-AGB stars) and the star formation.
The Large-Sky-Area Multi-object Fiber Spectroscopic Telescope (LAMOST) put forward by Shou-guan Wang and Ding-qiang Su is a special reflecting Schmidt telescope with the spherical mirror fixed and the correcting plate acts as both correcting plate and tractor. The correcting plate is installed on an alt-azimuth mounting and its aspherical figure is variable to meet the requirement for eliminate the spherical aberration of the spherical primary mirror when it is at variant orientations during the observation course and for different sky area. With LAMOST, both large aperture and large field of view can been obtained. Benefited from the LAMOST design and practice, a LAMOST-type telescope for full-sky survey is conceived for the Antarctic. Because of the favorable seeing condition and all-winter continuous observation, a telescope with aperture of the 2-m could be equivalent to the 4-m LAMOST. We preliminarily considered a 2-m telescope with a primary focus and a Cassegrain focus. The f-ratio of 5 and FOV 3-degree for the primary focus, and f-ratio of 15 and 8 minutes FOV with the diffraction limited image for the Cassegrain focus. In this paper, the scientific goals, the optical system of the telescope, particular material and technique which are applicable under the extreme low temperature condition at the Antarctic are described.
We present preliminary results of a comparison of possible Antarctic telescope locations based on the results of a
regional climate model. The simulation results include predictions for temperature, wind speed, seeing, precipitable
water vapor, and cloud cover. The domain of the simulation is the entire Antarctic continent for the 2004 winter season.
By incorporating lateral forcing, our simulation captures the effects of weather systems that can affect even the interior
regions of the Antarctic plateau. The simulation also shows maritime air advection into the plateau interior. We find the
model predictions are generally in good agreement with measurements made at the South Pole and Dome C. The
simulation results suggest that the Dome F and Dome A regions are potentially very good sites and are generally
superior to Dome C.
Recent data have shown that Dome C, on the Antarctic plateau, is an exceptional site for astronomy, with atmospheric
conditions superior to those at any existing mid-latitude site. Dome C, however, may not be the best site on the
Antarctic plateau for every kind of astronomy. The highest point of the plateau is Dome A, some 800 m higher than
Dome C. It should experience colder atmospheric temperatures, lower wind speeds, and a turbulent boundary layer that
is confined closer to the ground. The Dome A site was first visited in January 2005 via an overland traverse, conducted
by the Polar Research Institute of China. The PRIC plans to return to the site to establish a permanently manned station
within the next decade. The University of New South Wales, in collaboration with a number of international institutions,
is currently developing a remote automated site testing observatory for deployment to Dome A in the 2007/8 austral
summer as part of the International Polar Year. This self-powered observatory will be equipped with a suite of site
testing instruments measuring turbulence, optical and infrared sky background, and sub-millimetre transparency. We
present here a discussion of the objectives of the site testing campaign and the planned configuration of the observatory.
The brightness of the night sky at an astronomical site is one of the principal factors that determine the quality
of available optical observing time. At any site the optical night sky is always brightened with airglow, zodiacal
light, integrated starlight, diffuse Galactic light and extra-galactic light. Further brightening can be caused
by scattered sunlight, aurorae, moonlight and artificial sources. Dome C exhibits many characteristics that
are extremely favourable to optical and IR astronomy; however, at this stage few measurements have been
made of the brightness of the optical night sky. Nigel is a fibre-fed UV/visible grating spectrograph with a
thermoelectrically cooled 256 × 1024 pixel CCD camera, and is designed to measure the twilight and night sky
brightness at Dome C from 250 nm to 900 nm. We present details of the design, calibration and installation of
Nigel in the AASTINO laboratory at Dome C, together with a summary of the known properties of the Dome C
The Gattini cameras are two site testing instruments for the measurement of optical sky brightness, large area cloud cover and auroral detection of the night sky above the high altitude Dome C site in Antarctica. The cameras have been in operation since January 2006. The cameras are transit in nature and are virtually identical, both adopting Apogee Alta ccd detectors. The camera called Gattini-SBC images a 6 degree field centred on the South Pole, an elevation of 75° at the Dome C site. The camera takes repeated images of the same 6 degree field in the Sloan g' band (centred on 477nm) and, by adopting a lens with sufficiently long focal length, one can integrate the sky background photons and directly compare to the equivalent values of the stars within the field. The second camera, called Gattini-allsky, incorporates a fish-eye lens and images ~110 degree field centred on local zenith. By taking frequent images of the night sky we will obtain long term cloud cover statistics, measure the sky background intensity as a function of solar and lunar altitude and phase and directly measure the spatial extent of bright aurora if present and when they occur. An overview of the project is presented together with preliminary results from data taken since operation of the cameras in January 2006.
A survey of northwest Africa and southern Spain (including the Canary Islands) has been carried out using satellite data from the Meteosat Operational Service (in geostationary orbit at 0o longitude). The study was funded by European Southern Observatory (ESO) as part of the site survey effort for the Overwhelmingly Large Telescope (OWL), recently re-baselined as the European Extremely Large Telescope (E-ELT). Cloud cover and water vapor were surveyed over the area 20oN to 40oN and 20oW to 10oE using satellite data for the 7-year period January 1996 to December 2002. The study included a calibration of the Upper Tropospheric Humidity (UTH) for Meteosat-5, an aerial analysis of cloud cover and precipitable water vapor (PWV) and a verification of the satellite cloud cover using ground-based observations of sky conditions derived from extinction measurements made at the Observatorio del Roque de los Muchachos (ORM) on La Palma. In view of the importance of establishing the accuracy of the satellite method, a summary of results from earlier verification studies has been included in the relevant section.
We present the results of vertical profiles of refractive index structure constant Cn2(h) measurements made at the 1-m telescope, La Silla Observatory (ESO,Chile) using the generalized SCIDAR technique. Observations took place during
July, August, November, 2002 and February 2003. The instrumentation, computer interface and a preliminary reduction
software were provided by the Imperial College (London) scientific group. We describe the SCIDAR image processing
technique and two inverting methods. The first, proposed by the Imperial College group, is based on the Tikhonov
regularization and the second, on use at Nice University, is based on maximum entropy. Performances of both methods
agree well. The profile integrals are compared to simultaneous DIMM seeing measurements made at La Silla