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The Dark Energy Spectroscopic Instrument (DESI) is under construction and will be used to measure the expansion history of the Universe using the Baryon Acoustic Oscillation (BAO) technique and the growth of structure using redshift-space distortions (RSD). The spectra of 30 million galaxies over 14000 sq deg will be measured over the course of the experiment. In order to provide spectroscopic targets for the DESI survey, we are carrying out a three-band (g,r,z ) imaging survey of the sky using the NOAO 4-m telescopes at Kitt Peak National Observatory (KPNO) and the Cerro Tololo Interamerican Observatory (CTIO). At KPNO, we will use an upgraded version of the Mayall 4m telescope prime focus camera, Mosaic3, to carry out a z-band survey of the Northern Galactic Cap at declinations δ≥+30 degrees. By equipping an existing Dewar with four 4kx4k fully depleted CCDs manufactured by the Lawrence Berkeley National Laboratory (LBNL), we increased the z-band throughput of the system by a factor of 1.6. These devices have the thickest active area fielded at a telescope. The Mosaic3 z-band survey will be complemented by g-band and r-band observations using the Bok telescope and 90 Prime imager on Kitt Peak. We describe the upgrade and performance of the Mosaic3 instrument and the scope of the northern survey.

The Evryscope is a new type of telescope which covers the entire accessible sky in each exposure. Its 8000- square-degree field-of-view and 691 MPix telescope is sensitive to exoplanet transits and other short timescale events not discernible from existing large-sky-area astronomical surveys. The telescope, which places 24 separate individual telescopes into a common mount which tracks the entire accessible sky with only one moving part, is building 1%-precision, many-year-length, high-cadence light curves for every accessible object brighter than ~16th magnitude. The camera readout times are short enough to provide near-continuous observing, with a 97% survey time efficiency. The Evryscope has the largest survey grasp of any current ground-based survey, and for bright-object high-cadence observations is the only existing survey within an order of magnitude of LSST's etendue. We deployed the Evryscope, funded by NSF/ATI, at CTIO in May 2015. We here present the telescope design, performance, and project status.

With the rapid development of multi-objective astronomical survey telescope technology, the heat of focal plate which high-density optical fiber positioners were mounted in has become the key factor of system precision. The new integrated cooling system designed multi curved composite grooves on the surface of focal plate for forced convection was proposed. Meanwhile, the manufacturing process, sealing structure and heat dissipation performance of the system were analyzed and tested with detail in the paper. The experimental results suggested that the new integrated cooling system of focal plate has a fast response speed and good heat dissipation performance.

The Observatorio Astrofisico de Javalambre in Spain will conduct an all-sky astronomical surveys using multi-bands, where optical filters are needed. 54 narrow bandpass (FWHM = 14.5 nm) filters will continuously populate the spectrum between 370 to 920 nm with 10.0 nm steps. Here results on 2 filters with center wavelength of 460 nm and 470 nm and blocking from 250 to 1050 nm with OD5 will be shown. The filters have a maximum transmission of larger than 85% and a transmitted wavefront error of better than λ/2 over an aperture >~ 100mm.

The Observatorio Astrofisico de Javalambre in Spain will conduct an all-sky astronomical survey using multi-bands, where optical filters are needed. These filters are narrow bandpass steep edge filters (FWHM = 14.5 nm) in a spectrum between 390 to 920 nm with 10.0 nm steps. In order to fulfill the demanding requirements for final scientific image quality and transmitted wavefront error a new white-light Shack Hartmann sensor and difficult refractive index measurements of the sub-assembly were needed. In addition due to the spectral requirements the design and manufacturing of the filters were pushed at its technological limit.

The Observatorio Astrofisico de Javalambre (OAJ) is a new Spanish astronomical facility particularly designed for carrying out large sky surveys. The OAJ is mainly motivated by the development of J-PAS, the Javalambre- PAU Astrophysical Survey, an unprecedented astronomical survey that aims to observe 8500 deg2 of the sky with a set of 54 optical contiguous narrow-band filters (FWHM ~14 nm) and 5 mid and broad-band ones. J-PAS will provide a low resolution spectrum (R ~ 50) for every pixel of the Northern sky down to AB~22:5 - 23:5 per square arcsecond (at 5 σ level), depending on the narrow-band filter, and ~ 2 magnitudes deeper for the redder broad-band filters. The main telescope at the OAJ is the Javalambre Survey Telescope (JST/T250), an innovative Ritchey-Chretien, alt-azimuthal, large-etendue telescope with a primary mirror diameter of 2.55m and 3 deg (diameter) FoV. The JST/T250 is the telescope devoted to conduct J-PAS with JPCam, a panoramic camera of 4.7 deg2 FoV and a mosaic of 14 large format CCDs that, overall, amounts to 1.2 Gpix. The second largest telescope at the OAJ is the Javalambre Auxiliary Survey Telescope (JAST/T80), a Ritchey-Chretien, German-equatorial telescope of 82 cm primary mirror and 2 deg FoV, whose main goal is to perform J-PLUS, the Javalambre Photometric Local Universe Survey. J-PLUS will cover the same sky area of J-PAS using the panoramic camera T80Cam with 12 filters in the optical range, which are specifically defined to perform the photometric calibration of J-PAS. The OAJ project officially started in mid 2010. Four years later, the OAJ is mostly completed and the first OAJ operations have already started. The civil work and engineering installations are finished, including the telescope buildings and the domes. JAST/T80 is at the OAJ undertaking commissioning tasks, and JST/T250 is in AIV phase at the OAJ. Related astronomical subsystems like the seeing and atmospheric extinction monitors and the all-sky camera are fully operative. This paper aims to present a brief description and status of the OAJ main installations, telescopes and cameras. The current development and operation plan of the OAJ in terms of staffing organization, resources, observation scheduling, and data archiving, is also described.

A formation flight astronomical survey telescope (FFAST) is a new project that will cover a large sky area in hard X-ray. In particular, it will focus on the energy range up to 80keV. It consists of two small satellites that will go in a formation flight. One is an X-ray telescope satellite carrying a super mirror, and the other is a detector satellite carrying an SDCCD. Two satellites are put into a low earth orbit in keeping the separation of 12m. This will survey a large sky area at hard X-ray region to study the evolution of the universe.

The Observatorio Astrofisico 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.

All the manufacturers of stand-off CWA detectors communicate on the “same” characteristics. And one can find these parameters in the comparison table published between all the different products [1]. These characteristics are for example the maximum detection range, the number of different detectable compounds, the weight, the price, etc… All these parameters are good to compare products between them, but they omit one very important point: the reaction time in case of an unexpected incoming chemical threat, in the case of the surveillance application. To answer this important question, we imagine a new parameter: the Field Surface Scanning Rate (FSSR). This value is a classical parameter in astronomical survey, use by astronomers to compare the performance of different telescopes, they compute the quantity of sky (in sky square degrees) analyzed per unit of time by the system. In this paper we will compare this new figure-of-merit, the FSSR, of some commercially off the shelf stand-off detector. The comparison between classical FTIR system and gas imaging system in term of FSSR will be presented.

SAMI (Sydney-AAO Multi-object Integral field spectrograph) has the potential to revolutionise our understanding of galaxies, with spatially-resolved spectroscopy of large numbers of targets. It is the first on-sky application of innovative photonic imaging bundles called hexabundles, which will remove the aperture effects that have biased previous single-fibre multi-object astronomical surveys. The hexabundles have lightly-fused circular multi-mode cores with a covering fraction of 73%. The thirteen hexabundles in SAMI, each have 61 fibre cores, and feed into the AAOmega spectrograph at the Anglo-Australian Telescope (AAT). SAMI was installed at the AAT in July 2011 and the first commissioning results prove the effectiveness of hexabundles on sky. A galaxy survey of several thousand galaxies to z 0.1 will begin with SAMI in mid-2012.

The Observatorio Astrofisico 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. The OAJ facility will have two wide-field telescopes: the JST/T250; a 2.55-m telescope with a 3° diameter field of view (FoV), and the JAST/T80; an 0.83-m telescope with a 2° diameter FoV. First light instrumentation is being designed to exploit the survey capabilities of the OAJ telescopes. This paper describes the T80Cam, a wide-field camera that will be installed at the Cassegrain focus of the JAST/T80. It is equipped with an STA 1600 backside illuminated detector. This is a 10.5k-by-10.5k, 9μm pixel, high efficiency CCD that is read from 16 ports simultaneously, allowing read times of ~20s with a typical read noise of 6 electrons (rms). This full wafer CCD covers a large fraction of the JAST/T80’s FoV with a pixel scale of ~0.50"/pixel. T80Cam will observe in the wavelength range 330-1000nm through a set of 12 carefully optimized broad-, intermediate- and narrow-band filters. The camera is intended for surveys with the JAST/T80 telescope, starting with the planned J-PLUS (Javalambre Photometric Local Universe Survey), a multi-band photometric all-sky survey that will be completed in about 2 years and will reach AB∼ 23 mag (5σ level) with the SDSS filters.

Throughout the course of many years of observations at the VLT, the phase 2 software applications supporting the specification, execution and reporting of observations have been continuously improved and refined. Specifically the introduction of astronomical surveys propelled the creation of new tools to express more sophisticated, longer-term observing strategies often consisting of several hundreds of observations. During the execution phase, such survey programs compete with other service and visitor mode observations and a number of constraints have to be considered. In order to maximize telescope utilization and execute all programs in a fair way, new algorithms have been developed to prioritize observable OBs taking into account both current and future constraints (e.g. OB time constraints, technical telescope time) and suggest the next OB to be executed. As a side effect, a higher degree of observation automation enables operators to run telescopes mostly autonomously with little supervision by a support astronomer. We describe the new tools that have been deployed and the iterative and incremental software development process applied to develop them. We present our key software technologies used so far and discuss potential future evolution both in terms of features as well as software technologies.

There are many ways to solve the challenging problem of making a high performance robotic observatory from scratch. The Observatorio Astrof\'isico 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. The OAJ control system has been designed under a global point of view including not only astronomical subsystems but also infrastructure and other facilities. Three main factors have been considered in the design of a global control system for the robotic OAJ: quality, reliability and efficiency. We propose CIA (Control Integrated Architecture) design and OEE (Overall Equipment Effectiveness) as a key performance indicator in order to improve operation processes, minimizing resources and obtain high cost reduction maintaining quality requirements. The OAJ subsystems considered for the control integrated architecture are the following: two wide-field telescopes and their instrumentation, active optics subsystems, facilities for sky quality monitoring (seeing, extinction, sky background, sky brightness, clouds distribution, meteorological station), domes and several infrastructure facilities such as water supply, glycol water, water treatment plant, air conditioning, compressed air, LN2 plant, illumination, surveillance, access control, fire suppression, electrical generators, electrical distribution, electrical consumption, communication network, Uninterruptible Power Supply and two main control rooms, one at the OAJ and other remotely located in Teruel at 40km from the observatory, connected through a microwave radio-link. Here we present the OAJ strategy in control design to achieve maximum quality efficiency for the observatory processes and operations, giving practical examples of our approach., Comment: Two essential concepts to apply in the design of observatories control systems: OEE - Overall Equipment Effectiveness CIA - Control Integrated Architecture

The project of much-anticipated LAMOST (Large sky Area Multi-Object fibre Spectroscopic Telescope) has successfully been inspected and accepted at national-level evaluation. It will become the world’s most powerful meter-class level ground astronomical optical survey telescope. The ever-ambitious project throughout the development history of Chinese astronomical optics telescopes has brought an extraordinary challenge to its control system from all-round aspects. Painstaking effort has been made to the R&D of the control system from its design strategy, functionality analyses to most subtle technical solutions, and of course efficient engineering management is also included. A number of papers highlighting the anticipated LAMOST control system have previously been published during the course of the project evolving. However, much lesson and experience have been learned since 10 years ago. Now the telescope with all its facilities and observation chamber has been put into trial observation. This is the time to review the past and ponder over the future of the control system as a whole against the functional telescope in current reality. Lesson and experience are discussed. Some considerations for improving the system efficiency and the accessibility are presented too in this paper.

The Large Synoptic Survey Telescope (LSST) is a proposed ground based telescope that will perform a comprehensive astronomical survey by imaging the entire visible sky in a continuous series of short exposures. Four special purpose rafts, mounted at the corners of the LSST science camera, contain wavefront sensors and guide sensors. Wavefront measurements are accomplished using curvature sensing, in which the spatial intensity distribution of stars is measured at equal distances on either side of focus by CCD detectors. The four Corner Rafts also each hold two guide sensors. The guide sensors monitor the locations of bright stars to provide feedback that controls and maintains the tracking of the telescope during an exposure. The baseline sensor for the guider is a Hybrid Visible Silicon hybrid-CMOS detector. We present here a conceptual mechanical and electrical design for the LSST Corner Rafts that meets the requirements imposed by the camera structure, and the precision of both the wavefront reconstruction and the tracking. We find that a single design can accommodate two guide sensors and one split-plane wavefront sensor integrated into the four corner locations in the camera.

Multi-purpose Infra-Red Imaging System (MIRIS) is the main payload of the Korea Science and Technology Satellite-3 (STSAT-3), which is being developed by Korea Astronomy & Space Science Institute (KASI). MIRIS is a small space telescope mainly for astronomical survey observations in the near infrared wavelengths of 0.9~2 μm. A compact wide field (3.67 x 3.67 degree) optical design has been studied using a 256 x 256 Teledyne PICNIC FPA IR sensor with a pixel scale of 51.6 arcsec. The passive cooling technique is applied to maintain telescope temperature below 200 K with a cold shutter in the filter wheel for accurate dark calibration and to reach required sensitivity, and a micro stirling cooler is employed to cool down the IR detector array below 100K in a cold box. The science mission of the MIRIS is to survey the Galactic plane in the emission line of Paschen-α (Paα, 1.88 μ;m) and to detect the cosmic infrared background (CIB) radiation. Comparing the Paα map with the Hα data from ground-based surveys, we can probe the origin of the warm-ionized medium (WIM) of the Galaxy. The CIB is being suspected to be originated from the first generation stars of the Universe and we will test this hypothesis by comparing the fluctuations in I (0.9~1.2 um) and H (1.2~2.0 um) bands to search the red shifted Lyman cutoff signature. Recent progress of the MIRIS imaging system design will be presented.

The joint USand German SOFIA project to develop and operate a 2.5 - meter infrared airborne telescope in a Boeing 747-SP is now well into development. Work on the aircraft and the telescope has started. First science fiights will begin in 2003 with 20% of the observing time assigned to German investigators. The observatory is expected to operate for over 20 years. The sensitivity, characteristics and science instrument complement are discussed. SOFIA will have instrumentation that will allow astronomical surveys that were not possible on the KAO. A future SOFIA project related to astrochemistry is discussed.

Dome C is considered a site particularly suited for wide-field imaging thanks to its shallow surface turbulent layer and its weak turbulence in the free atmosphere. What is the quantitative gain one can hope to achieve at Dome C with respect to a mid-latitude site? With the point spread function model defined analytically in the spatial frequency domain we are better able to connect the morphological and statistical behaviour of the turbulence profile to the trade-off between the adaptive telescope's field of view and a figure of merit for survey rate. A familiar image quality figure of merit is the radius of 50% encircled energy, and for J-band images it quickly identifies the requirement that will make a Dome C telescope, 8 meters above the ice, competitive with a mid-latitude one. From the radius of 50% encircled energy we derive the wide-field survey rate equation to estimate the impact of uncertainty in the vertical distribution of ground-layer turbulence on the trade-off between field of view (in the domain 10-20 arcminutes) and their survey rate.

Astronomical surveys have demonstrated an enormous capability for increasing our understanding of the universe around us. There are significant wavelength regions, which for various reasons are poorly sampled. Powerful diagnostics of hot gas in the universe are well understood, but there are few instruments capable of making measurements at the wavelengths of the most important lines (103 nm, 123 nm, and 155 nm, the lithium-like series of O, N, and C). No complete survey has been done with moderate spatial resolution in emission even though virtually all measurements capable of detecting the presence of lithium-like oxygen do so. We present a technique to eliminate the spectral-spatial confusion inherent in a wide field imaging spectrograph based on a type of imaging spectrograph that takes advantage of the large, well-corrected field of view from a three-mirror anastigmat (TMA) in conjunction with aberration-corrected holography applied to the tertiary.

The UKIRT Wide-Field Camera (WFCAM) was commissioned in two phases between October and December 2004, and March and April 2005. It has been carrying out full-scale sky survey operations since May 2005. This paper describes the commissioning process and compares actual performance on the telescope with specifications in four key areas: optical image quality including delivered FWHM and ghosting etc., noise and sensitivity in the infrared and on the visible autoguider, array artifacts such as crosstalk and persistent images, and observing efficiency. A comprehensive program of science verification was carried out before commencing the UKIRT Infrared Deep Sky Survey (UKIDSS).

The CTIO V. M. Blanco 4-m telescope is to be the host facility for the Dark Energy Survey (DES), a large area optical survey intended to measure the dark energy equation of state parameter, w, to a precision of ˜ 5%. The survey is expected to take 5 years and use a new 520 megapixel CCD prime focus imaging system: the Dark Energy Camera (DECam). In preparation for the arrival of DECam, we plan numerous upgrades to the telescope, including a new telescope control system optimized for programmed and queued survey observations, modifications to the telescope itself to improve reliability and performance, extended real-time telemetry of site and facility characteristics, and a distributed observer interface allowing for on- and off-site observations and real time quality control. These upgrades are specifically motivated by the scientific goals of the DES but will also improve community use of the telescope.

Data from the two IR survey cameras WFCAM (at UKIRT in the northern hemisphere) and VISTA (at ESO in the southern hemisphere) can arrive at rates approaching 1.4 TB/night for of order 10 years. Handling the data rates on a nightly basis, and the volumes of survey data accumulated over time each present new challenges. The approach adopted by the UK's VISTA Data Flow System (for WFCAM & VISTA data) is outlined, emphasizing how the design will meet the end-to-end requirements of the system, from on-site monitoring of the quality of the data acquired, removal of instrumental artefacts, astrometric and photometric calibration, to accessibility of curated and user-specified data products in the context of the Virtual Observatory. Accompanying papers by Irwin et al and Hambly et al detail the design of the pipeline and science archive aspects of the project.

Visualisation is a powerful tool for understanding the large data sets typical of astronomical surveys and can reveal unsuspected relationships and anomalous regions of parameter space which may be difficult to find programatically. Visualisation is a classic information technology for optimising scientific return. We are developing a number of generic on-line visualisation tools as a component of the Australian Virtual Observatory project. The tools will be deployed within the framework of the International Virtual Observatory Alliance (IVOA), and follow agreed-upon standards to make them accessible by other programs and people. We and our IVOA partners plan to utilise new information technologies (such as grid computing and web services) to advance the scientific return of existing and future instrumentation. Here we present a new tool - VOlume - which visualises point data. Visualisation of astronomical data normally requires the local installation of complex software, the downloading of potentially large datasets, and very often time-consuming and tedious data format conversions. VOlume enables the astronomer to visualise data using just a web browser and plug-in. This is achieved using IVOA standards which allow us to pass data between Web Services, Java Servlet Technology and Common Gateway Interface programs. Data from a catalogue server can be streamed in eXtensible Mark-up Language format to a servlet which produces Virtual Reality Modeling Language output. The user selects elements of the catalogue to map to geometry and then visualises the result in a browser plug-in such as Cortona or FreeWRL. Other than requiring an input VOTable format file, VOlume is very general. While its major use will likely be to display and explore astronomical source catalogues, it can easily render other important parameter fields such as the sky and redshift coverage of proposed surveys or the sampling of the visibility plane by a rotation-synthesis interferometer.

We present three designs and tolerances of wide-field imagers (30'30 arc-minutes or larger) for astronomical surveying. Two infrared cameras (CPAPIR and PANORAMIX II) were designed for the 0.8-2.4 μm band and a third one (WIRCAM) for the visible and near-infrared band extending from 410 nm to 950 nm. The cameras are installed on the telescopes of the Canada-France-Hawaii (Hawaii, USA) and Mont Megantic Observatories (Quebec, Canada). The three cameras are compact, use only spherical refractive components and have an internal pupil accessible for insertion of filtering components. A Lyot stop must be used in the infrared camera for background rejection. For PANORAMIX II, a set of filters is used at the internal pupil. Correction of the large off-axis aberrations generated by the telescopes, wide spectral coverage, material choices, cryogenic temperature and alignment were the main design challenges. Also, tolerancing was particularly critical for the infrared cameras because they are cryogenically cooled, thus forbidding adjustment of internal components. The cameras’ theoretical performances are presented in terms of point-spread function, encircled energy and distortion.

The Max-Planck-Institut fuer extraterrestrische Physik (MPE), the Astrophysikalisches Institut Potsdam (AIP) and the Institute fuer Astronomie und Astrophysik der Universitat Tubingen (IAAT), together with European cooperation partners, have proposed to install an x-ray telescope on the International Space Station (ISS). The mission ROSITA will perform the first imaging all-sky survey in the medium energy x-ray range up to 10 keV with an unprecedented spectral and angular resolution. The main scientific goals are (1) to detect systematically all obscured accreting Black Holes in nearby galaxies and many new, distant active galactic nuclei, (2) to detect the hot intergalactic medium of several ten thousand galaxy clusters and groups and hot gas in filaments between clusters to map out the large scale structure in the Universe and to find in particular the rare massive distant clusters of galaxies for the study of cosmic structure evolution and (3) to study in detail the physics of galactic x-ray source populations, like pre-main sequence stars, supernova remnants, and x-ray binaries. In the hard x-ray band the ROSITA survey in this band, which was performed about 25 years ago. In the soft band the ROSITA survey will have a hundred times higher sensitivity and a hundred times better angular resolution than the last all-sky in this band, which was perforemd about 25 years ago. In the soft band the ROSITA survey will be more sensitive and have a substantially better energy and also angular resolution than the ROSAT all-sky survey. The telescope will consist of the seven 27-fold nested Wolter-1 mirror systems, the type already flown on ABRIXAS, and an ovel detector system currently being develoepd by MPE on the basis of the successful XMM pn-CCD technoloyg - a potential prototype for the planned ESA mission XEUS. Major improvements of the new camera are a higher time and energy resolution and significantly reduced ghost images. Within an industry study, recently completed, the general feasibility of such an astronomical survey telescope mounted on the ISS was established.

We give an overview of the current status of the VISTA (Visible and Infrared Survey Telescope for Astronomy) project to build a 4-m wide field survey telescope to be operated by ESO (the European Southern Observatory) at the Cerro Paranal Observatory in Chile. First light in 2006 will be with the Infrared (J, H, Ks) Camera with a 1.65 degrees diameter field of view able to accommodate sixteen 2k × 2k IR detectors with 0.34''pixel size. Some motivations driving the choice of site, current design, and operational mode are discussed. We outline some innovative features of the system, which were necessary to deal with, or arose from, the very large field of view, including a cold baffle (rather than cold stop) in the IR camera, lack of traditional telescope focus, f/1 primary mirror, thermal control of the IR camera etc. These are cross-referenced to more detailed analyses by members of the VISTA Project Office team presented at this meeting. Estimated IR performance for VISTA is given. The scientific gains from adding the 2.1 degrees field of view Visible Camera when funds become available are stressed. The problems of processing 0.4TB of survey data acquired each night are discussed.

The Sloan Digital Sky Survey (SDSS) imaging camera saw first light in May 1998, and has been in regular operation since the start of the survey in April 2000. We review here key elements in the design of the instrument driven by the specific goals of the survey, and discuss some of the operational issues involved in keeping the instrument ready to observe at all times and in monitoring its performance. We present data on the mechanical and photometric stability of the camera, using on-sky survey data as collected and processed to date.

This paper describes the conceptual design for a near infrared camera for the Visible and Infrared Survey Telescope for Astronomy (VISTA). VISTA is a 4m class survey telescope that is being designed to perform pre-planned, ground-based astronomical surveys of the Southern sky from ESO's Cerro Paranal Observatory in Chile. The IR Surveys will be carried out in the J, H and Kshort wave-bands at fainter magnitudes than those produced by the current generation of survey telescopes. To maximise throughput and survey efficiency, the camera has been completely integrated with the overall optical design with the telescope mirrors providing the power and the camera optics the wavefront correction. The camera design employs a non-traditional approach to control stray light by using cryogenic baffles rather than the more traditional cold-stop approach. The very large optical field available, 1.6° diameter with a plate scale of approximately 57μm/arcsec, means that the focal plane can accommodate sixteen 2k×2k IR detectors thus forming the largest IR focal plane used in ground based astronomy to date. The 67 Mpixel focal plane will generate a significant data rate. Each exposure will comprise 270 MB and a typical night will generate 400 GB.

The design of VISTA (Visible and Infrared Survey Telescope for Astronomy) requires close interaction between the science requirements, the optical and active mechanical design of the telescope and its instrumentation with the wavefront sensing. The optical design is based on an integrated approach of the telescope with tow separate cameras, one working in the IR waveband and the other working in the Visible waveband. The large field of view (2 degrees in the visible and 1.65 degrees in the IR), the seeing-limited resolution required (FWHM of 0.4 arcsec for the visible and 0.5 arcsec for the IR), the technological advance in active telescopes and large IR arrays and the f/1 quasi Ritchey-Chretien telescope design, makes this telescope a very powerful tool in performing high resolution and large astronomical surveys. A system analysis, modeling the various sources of errors such as optical aberrations, surface errors, control errors, environmental effects and detector effects is presented in this paper.

The new wide-field infrared camera (WFCAM) for the 3.8 m United Kingdom Infrared Telescope (UKIRT) and the Visible and Infrared Survey Telescope for Astronomy (VISTA) are two future facilities to provide sky survey data to complement the latest 8 m-class telescopes. Both use large lenses (with a diameter greater than 500 mm) made of fused silica. The cryostat window used for the IR channel in VISTA is 950 mm in diameter. The specification and cryogenic mounting of these components, some of which with aspherical surfaces, are an opto-mechanical challenge and are described in this paper. We also discuss various aspects of the manufacturing and testing.

In this paper, the authors describe the use of data mining techniques to search for radio-emitting galaxies with a bent-double morphology. In the past, astronomers from the FIRST (Faint Images of the Radio Sky at Twenty-cm) survey identified these galaxies through visual inspection. This was not only subjective but also tedious as the on-going survey now covers 8000 square degrees, with each square degree containing about 90 galaxies. In this paper, they describe how data mining can be used to automate the identification of these galaxies. They discuss the challenges faced in defining meaningful features that represent the shape of a galaxy and their experiences with ensembles of decision trees for the classification of bent-double galaxies.

A number of preliminary optical designs for a new generation of 4 meter astronomical survey telescopes have been investigated. These have large fields of view and operate in both the visible and near IR astronomical wavebands. Typical requirements for dual band systems of this type are presented. Two designs for prime focus refractive field corrector systems are presented, with and without aspheric surfaces. The use of aspheric surfaces on the field corrector lenses is shown to allow a large field of view to be achieved. A design for a three mirror reflective system is presented which also allows a 2 degree field to be achieved. An IR imager, based on a modified Schmidt camera, is presented which allows a 1 degree field of view to be achieved. Additionally, a modified Ritchey-Chretien telescope, incorporating refracting field corrector lenses is presented. This design provides a large field of view over both the visible and IR wavebands. The mechanical constraints of combining these systems into dual channel systems are also discussed.

The advent of inexpensive large aperature near diffraction limited Liquid Mirror Telescopes (LMT's) makes possible applications not sensitive to their near vertical viewing nature; such as, astronomical surveys, space debris surveys, lidar collectors, and laser radiation concentrators, for plasma creation experiments in the sky. LMTs are easily an order of magnitude less expensive than a polished glass reflectors, which are only approximations to the naturally perfect parabolic surtace created by a rotating liquid. Highly reflecting liquid mercury is easily cleaned and safe when handled correctly.

The optical design of Isophot-S, the low-resolution NIR spectrophotometer for the IR Space Observatory (ISO), is described and illustrated with drawings and graphs of test data. The ISO is to be launched in 1993 as a successor to IRAS for astronomical surveys at 2.5-200 microns. Isophot-S has an aperture of 24 arcsec sq, and the two 64-pixel Si:Ga detector arrays have noise-equivalent power of about 5 x 10 to the -17th W/sq rt Hz at 15 microns, corresponding to 1-sigma 1-sec detection sensitivity 400 mJy for a point source at 12 microns or surface brightness 0.8 mJy/sq arcsec for an extended source. The system comprises two grating spectrometers, one operating at 2.5-5 microns with resolution 40 nm and one operating at 6-12 microns with resolution 90 nm.

The USAF Satellite Infrared Experiment (SIRE) will offer the opportunity to conduct space-based astronomical measurements. Experiments include formation of star catalogs, the determination of the color temperature of stars and asteroids, and the measurement of extended radiation. In this paper some of the data processing techniques required for these experiments are discussed and evaluated. In particular, tradeoffs in the design of efficient star cataloging algorithms, and a methodology for extracted extended background are discussed. These algorithms are evaluated using simulated data. Performance results for both the cataloging algorithm and the background estimation algorithm are discussed.