A key technical driver for the MOONS (Multi-object Optical and Near Infrared Spectrograph) instrument is to provide accurate sky subtraction using pairs of adjacent fibres. To achieve this the fibre positioners must achieve extremely close proximity, and the throughput of each fibre must be well characterised. The latter of these conditions requires a calibration system capable of creating a flat field input to the fibres to an illumination uniformity of less than 2% variation. Given the very limited space available in the instrument, a number of systems were considered to achieve this. After consideration of the available options, a novel system using a digital micromirror device (DMD) was selected for implementation. These devices has a long history in commercial displays, and provide a compact, highly responsive, and robust solution to many structured light applications. This paper explains the design and manufacture of the calibration module, as well as the intended test plan for the system.
ERIS is an instrument that will both extend and enhance the fundamental diffraction limited imaging and spectroscopy capability for the VLT. It will replace two instruments that are now being maintained beyond their operational lifetimes, combine their functionality on a single focus, provide a new wavefront sensing module that makes use of the facility Adaptive Optics System, and considerably improve their performance. The instrument will be competitive with respect to JWST in several regimes, and has outstanding potential for studies of the Galactic Center, exoplanets, and high redshift galaxies. ERIS had its final design review in 2017, and is expected to be on sky in 2020. This contribution describes the instrument concept, outlines its expected performance, and highlights where it will most excel.
HiPERCAM is a five channel fast photometer to study high temporal variability of the universe, covering from 0.3 to 1.0 microns in five wavebands. HiPERCAM uses custom-made 2Kx1K split-frame transfer CCDs mounted in separate compact camera heads and cooled by thermoelectric coolers to 180K. The demands on the readout system are very unique to this instrument in that all five CCDs are operated in a pseudo drift window mode along with the normal windowing, binning and full-frame modes. The pseudo drift mode involves reading out small window regions from 2 quadrants of each CCD, with the possibility to exceed 1 kHz window rates per output channel. The CCDs are custom manufactured by Teledyne e2v to allow independent serial clock controls for each output. The devices are manufactured in standard and deep-depletion processes with appropriate anti-reflection coatings to achieve high quantum efficiencies in each of the five wavebands. An ESO NGC controller has been configured to control and readout all five CCDs. The data acquisition software has been modified to provide GPS timestamping of the data and access to the acquired data in real time for the data reduction software. The instrument has had its first light and first science observations on the 4.2m William Herschel Telescope, La Palma during a commissioning run in October 2017 and subsequently on the 10.4m Gran Telescopio Canarias in February 2018 and science observations in April 2018. This paper will present the details of the preamplifier electronics, configuration of the readout electronics and the data acquisition software to support the unique readout modes along with the overall performance of the instrument.
The Enhanced Resolution Imager and Spectrograph (ERIS) is a next-generation, adaptive optics assisted, near-IR imager and integral field spectrograph (IFS) for the Cassegrain focus of the Very Large Telescope (VLT) Unit Telescope 4. It will make use of the Adaptive Optics Facility (AOF), comprising the Deformable Secondary Mirror (DSM) and the UT4 Laser Guide Star Facility (4LGSF). It is a rather complex instrument, with its state of the art AO system and two science channels. It is also meant to be a "workhorse" instrument and offers many observation modes. ERIS is being built by a Consortium of European Institutes comprising MPE Garching (D), ATC (UK), ETH Zürich (CH), Leiden University (NL) and INAF (I) in collaboration with ESO. The instrument passed Final Design Review in mid-2017 and is now in the MAIT phase. In this paper we describe the design of the ERIS Instrument Software (INS), which is in charge of controlling all instrument functions and implementing observation, calibration and maintenance procedures. The complexity of the instrument is reflected in the architecture of its control software and the number of templates required for operations. After a brief overview of the Instrument, we describe the general architecture of the ERIS control network and software. We then discuss some of the most interesting aspects of ERIS INS, like the wavefront sensors function control, AO secondary loops, IFS quick-look processing and the on-line processing for high-contrast imaging observations. Finally, we provide some information about our development process, including software quality assurance activities.
HiPERCAM is a quintuple-beam imager that saw first light on the 4.2 m William Herschel Telescope (WHT) in October 2017 and on the 10.4 m Gran Telescopio Canarias (GTC) in February 2018. The instrument uses re- imaging optics and 4 dichroic beamsplitters to record ugriz (300–1000 nm) images simultaneously on its five CCD cameras. The detectors in HiPERCAM are frame-transfer devices cooled thermo-electrically to 90°C, thereby allowing both long-exposure, deep imaging of faint targets, as well as high-speed (over 1000 windowed frames per second) imaging of rapidly varying targets. In this paper, we report on the as-built design of HiPERCAM, its first-light performance on the GTC, and some of the planned future enhancements.
ERIS will be the next-generation AO facility on the VLT, combining the heritage of NACO imaging, with the spectroscopic capabilities of an upgraded SINFONI. Here we report on the all-new NIX imager that will deliver diffraction-limited imaging from the J to M band. The instrument will be equipped with both Apodizing Phase Plates and Sparse Aperture Masks to provide high-angular resolution imagery, especially suited for exoplanet imaging and characterization. This paper provides detail on the instrument’s design and how it is suited to address a broad range of science cases, from detailed studies of the galactic centre at the highest resolutions, to studying detailed resolved stellar populations.
HARPS-N (High-Accuracy Radial-Velocity planetary Search) is an instrument designed for the measurement of Radial
Velocities (RV) at highest accuracy. It is located in the Northern hemisphere and installed at the TNG on La Palma
Island. It has allowed scientists to confirm and characterize Earth-like mass planets: Kepler-78b. In this paper, we
present the design of Instrument Control Software (ICS) based on LabVIEW, the key features of implementation such as
the XML-RPC, labVIEW Classes and Shared Variables. We also present here the auto-guiding and fibre hole finding
algorithm. Use of XML-RPC in Labview for ICS with COTS hardware has made the development of HARAPS-N ICS
easily in implementing and integrating with other software in a limited construction time scale.
The Telescopio Nazionale Galileo (TNG) hosts, starting in April 2012, the visible spectrograph HARPS-N. It is based
on the design of its predecessor working at ESO's 3.6m telescope, achieving unprecedented results on radial velocity
measurements of extrasolar planetary systems. The spectrograph's ultra-stable environment, in a temperature-controlled
vacuum chamber, will allow measurements under 1 m/s which will enable the characterization of rocky, Earth-like
planets. Enhancements from the original HARPS include better scrambling using octagonal section fibers with a shorter
length, as well as a native tip-tilt system to increase image sharpness, and an integrated pipeline providing a complete set
Observations in the Kepler field will be the main goal of HARPS-N, and a substantial fraction of TNG observing time
will be devoted to this follow-up. The operation process of the observatory has been updated, from scheduling
constraints to telescope control system. Here we describe the entire instrument, along with the results from the first
HARPS North is the twin of the HARPS (High Accuracy Radial velocity for Planetary Search) spectrograph operating in
La Silla (Chile) recently installed on the TNG in La Palma observatory and used to follow-up, the "hot" candidates
delivered by the Kepler satellite. HARPS-N is delivered with its own software that completely integrates with the TNG
control system. A special care has been dedicated to develop tools that will assist the astronomers during the whole
process of taking images: from the observation schedule to the raw image acquisition. All these tools are presented in the
paper. In order to provide a stable and reliable system, the software has been developed keeping in mind concepts like
failover and high-availability. HARPS-N is made of heterogeneous systems, from normal computer to real-time systems,
that's why the standard message queue middleware (ActiveMQ) was chosen to provide the communications between
different processes. The path of operations starting with the Observation Blocks and ending with the FITS frames is fully
automated and could allow, in the future, the completely remote observing runs optimized for the time and quality
SCUBA-2 is a revolutionary 10,000 pixel wide-field submillimetre camera, recently commissioned and now operational
at the James Clerk Maxwell Telescope (JCMT). Twin focal planes each consist of four 32 by 40 sub-arrays of
superconducting Transition Edge Sensor (TES) bolometers, the largest combined low temperature bolometer arrays in
operation, to provide simultaneous imaging at wavelengths of 450 and 850 microns. SCUBA-2 was designed to map
large areas of sky more than 100 times faster than the original ground breaking SCUBA instrument and has achieved this
goal. In this paper we describe the performance of the instrument and present results of characterising the eight science
grade TES bolometer arrays. We discuss the steps taken to optimise the setup of the TES arrays to maximise mapping
speed and show how critical changes to the sub-array module thermal design, the introduction of independent focal plane
and 1K temperature control and enhancements to the cryogenics have combined to significantly improve the overall
performance of the instrument.
The high data rates and unique operation modes of the SCUBA-2 instrument made for an especially challenging effort
to get it working with the existing JCMT Observatory Control System (OCS). Due to some forethought by the original
designers of the OCS, who had envisioned a SCUBA-2 like instrument years before it was reality, the JCMT was
already being coordinated by a versatile Real Time Sequencer (RTS). The timing pulses from the RTS are fanned out to
all of the SCUBA-2 Multi Channel Electronics (MCE) boxes allowing for precision timing of each data sample. The
SCUBA-2 data handing and OCS communications are broken into two tasks, one doing the actual data acquisition and
file writing, the other communicates with the OCS through Drama. These two tasks talk to each other via shared
memory and semaphores. It is possible to swap back and forth between heterodyne and SCUBA-2 observing simply by
selecting an observation for a particular instrument. This paper also covers the changes made to the existing OCS in
order to integrate it with the new SCUBA-2 specific software.
The most challenging of the metrology needs of multi-objects instruments is the registration of the pupil on the
deformable mirror which corrects the wavefront errors. Pick-off mirrors in multi-objects instruments and specially
spectrographs (MOS) require accurate positioning and simultaneous viewing of the pupil on the deformable mirror
(DM) and the focal plane image on the image slicer at the sub-micron level. A laboratory test prototype simulating the
telescope (E-ELT), the beam steering mirror (BSM) and the pupil imaging mirror (PIM), is presented to confirm the
correct positioning of the pupil on the DM and to provide the movements of the moveable optical elements to achieve it.
The opto-mechanical design and testing of this prototype is shown. The BSM stages (Goniometric cradle, Rotation, &
Linear) provide the key mechanical system elements, with precision alignment, resolution, and repeatability .
The design and behaviour of the control system is discussed; the ultimate aim of which is to adjust the BSM and PIM to
correct for any slight mis-positioning of the pick-off mirror and any temporal drift of all the components to achieve the
required alignment. The control system can also cope with flexure effects when required.
SCUBA-2 is a state of the art 10,000 pixel submillimeter camera installed and being commissioned at the James Clerk
Maxwell Telescope (JCMT) providing wide-field simultaneous imaging at wavelengths of 450 and 850 microns. At each
wavelength there are four 32 by 40 sub-arrays of superconducting Transition Edge Sensor (TES) bolometers, each
packaged with inline SQUID multiplexed readout and amplifier. In this paper we present the results of characterising
individual 1280 bolometer science grade sub-arrays, both in a dedicated 50mk dilution refrigerator test facility and in the
instrument installed at the JCMT.
The Atacama Cosmology Telescope (ACT) is designed to measure temperature anisotropies of the cosmic microwave background (CMB) at arcminute resolution. It is the first CMB experiment to employ a 32×32 close-packed array of free-space-coupled transition-edge superconducting bolometers. We describe the organization of the telescope systems and software for autonomous, scheduled operations. When paired with real-time data streaming and display, we are able to operate the telescope at the remote site in the Chilean Altiplano via the Internet from North America. The telescope had a data rate of 70 GB/day in the 2007 season, and the 2008 upgrade to three arrays will bring this to 210 GB/day.
The detector arrays for the SCUBA-2 instrument consist of TES bolometers with superconducting amplifier and
multiplexing circuits based on Superconducting Quantum Interference Devices (SQUIDs). The SCUBA-2 TES arrays
and their multiplexed SQUID readouts need to be set-up carefully to achieve correct performance. Algorithms have been
developed and implemented based on the first available commissioning grade detector, enabling the array to be set up
and optimized automatically.
The Millimeter Bolometer Array Camera (MBAC) was commissioned in the fall of 2007 on the new 6-meter
Atacama Cosmology Telescope (ACT). The MBAC on the ACT will map the temperature anisotropies of the
Cosmic Microwave Background (CMB) with arc-minute resolution. For this first observing season, the MBAC
contained a diffraction-limited, 32 by 32 element, focal plane array of Transition Edge Sensor (TES) bolometers
for observations at 145 GHz. This array was coupled to the telescope with a series of cold, refractive, reimaging
optics. To meet the performance specifications, the MBAC employs four stages of cooling using closed-cycle
3He/4He sorption fridge systems in combination with pulse tube coolers. In this paper we present the design of
the instrument and discuss its performance during the first observing season. Finally, we report on the status
of the MBAC for the 2008 observing season, when the instrument will be upgraded to a total of three separate
1024-element arrays at 145 GHz, 220 GHz and 280 GHz.
We present the results of characterization measurements on a 1280 pixel superconducting bolometer array designed for operation at wavelengths around 450 μm. The array is a prototype for the sub-arrays which will form the focal plane for the SCUBA-2 sub-mm camera, being built for the James Clerk Maxwell Telescope (JCMT) in Hawaii. With over 10 000 pixels in total, it will provide a huge improvement in both sensitivity and mapping speed over existing instruments. The array consists of molybdenum-copper bi-layer TES (transition edge sensor) pixels, bonded to a multiplexer. The detectors operate at a
temperature of approximately 175 mK, and require a heat sink at a temperature of approximately 60 mK. In contrast to previous TES arrays, the multiplexing elements are located beneath each pixel (an "in-focal plane" configuration). We present the results of electrical and optical measurements, and show that the optical NEP (noise equivalent power) is less than 1.4 × 10-16 W Hz-0.5 and thus within the goal of 1.5 × 10-16 W Hz-0.5.
SCUBA-2 is a second generation, wide-field submillimeter camera under development for the James Clerk Maxwell Telescope. With over 12,000 pixels, in two arrays, SCUBA-2 will map the submillimeter sky ~1000 times faster than the current SCUBA instrument to the same signal-to-noise. Many areas of astronomy will benefit from such a highly sensitive survey instrument: from studies of galaxy formation and evolution in the early Universe to understanding star and planet formation in our own Galaxy. Due to be operational in 2006, SCUBA-2 will also act as a "pathfinder" for the new generation of submillimeter interferometers (such as ALMA) by performing large-area surveys to an unprecedented depth. The challenge of developing the detectors and multiplexer is discussed in this paper.
NAOMI (Nasmyth Adaptive Optics for Multi-purpose Instrumentation) is a recently completed and commissioned astronomical facility on the 4.2m William Herschel Telescope. The system is designed to work initially with Natural Guide Stars and also to be upgradeable for use with a single laser guide star. It has been designed to work with both near infrared and optical instrumentation (both imagers and spectrographs). The system uses a linearised segmented adaptive mirror and dual-CCD Shack-Hartmann wavefront sensor together with a multiple-DSP real-time processing system. Control system parameters can be updated on-the-fly by monitoring processes and the system can self-optimize its base optical figure to compensate for the optical characteristics of attached scientific instrumentation. The scientific motivation, consequent specification and implementation of NAOMI are described, together with example performance data and information on future upgrades and instrumentation.
The JCMT, the world's largest sub-mm telescope, has had essentially the same VAX/VMS based control system since it was commissioned. For the next generation of instrumentation we are implementing a new Unix/VxWorks based system, based on the successful ORAC system that was recently released on UKIRT.
The system is now entering the integration and testing phase. This paper gives a broad overview of the system architecture and includes some discussion on the choices made. (Other papers in this conference cover some areas in more detail). The basic philosophy is to control the sub-systems with a small and simple set of commands, but passing detailed XML configuration descriptions along with the commands to give the flexibility required. The XML files can be passed between various layers in the system without interpretation, and so simplify the design enormously. This has all been made possible by the adoption of an Observation Preparation Tool, which essentially serves as an intelligent XML editor.
Within the last few years several manufacturers have been producing the 'next generation' of scientific CCDs. These devices have small pixels (approximately 15 micrometers), high UV and broad-band spectral response (greater than 80%), very low readout noise (less than 4 e- rms), large format (2048*4096) and close butting capability. We present examples of recent data taken on the WHT (at the Roque de los Muchachos Observatory, La Palma) obtained from one such device -- the EEV CCD42 array. The detector has been used for spectroscopy and direct imaging with excellent results. Design and performance details, as well as various special operational modes will be discussed. This device has been adopted for scientific imaging on the Gemini telescopes, as well as several other major observatories -- and so these first operational results should demonstrate the power of these new sensors. Variants of the CCD42 design are now being made to yield slightly different architectures and packaging options. We will compare predicted with actual performance, and discuss characteristics and applications of this new sensor.