The Multi Object Optical and Near-infrared Spectrograph (MOONS) instrument is the next generation multi-object spectrograph for the Very Large Telescope (VLT). The instrument combines the high multiplexing capability offered by 1000 optical fibres deployed by individual robotic positioners with a novel spectrograph able to provide both low- and high-resolution spectroscopy simultaneously across the wavelength range 0.64μm - 1.8μm. Powered by the collecting area of the 8-m VLT, MOONS will provide the astronomical community with a world-leading facility able to serve a wide range of Galactic, Extragalactic and Cosmological studies. This paper provides an updated overview of the instrument and its construction progress, reporting on the ongoing integration phase.

The MOONS (Multiple-Object Optical and Near-infrared Spectrograph) is a fibre-fed spectrograph for the European Southern Observatory’s Very Large Telescope. It will provide simultaneous observations of up to 1,000 objects covering the wavelength range 650 nm to 1800 nm. MOONS will also provide an observing mode with 500 object-sky pairs to provide precise sky-subtraction by nodding between object and sky. For this observing mode to be successful the instrument must be well calibrated and the relative throughput of each optical fibre known. The MOONS instrument throughput and wavelength calibration will be characterised, on a daily basis, using the on-board calibration system. The calibration system will illuminate the instrument via a deployable diffuse reflective screen located in front of the focal surface containing the optical fibres. The calibration system provides both spectral calibration via arc lamp illumination, and flat-field illumination via a Digital Micro-mirror Device (DMD) based projector system. This paper will provide a summary of the design and performance of the MOONS calibration system. Flat-field performance results will be presented which demonstrate the calibration unit achieves better than 2% peak to valley illumination uniformity across the 880 mm diameter flat-field screen.

The MOONS multi-object spectrograph relies on an array of 1000 fibre positioners to acquire targets in the focal plane. The fibre positioners have a larger overlap than similar instruments because MOONS can observe in the infrared. The large overlap gives MOONS the ability to acquire close pairs of object and sky targets, but it makes moving positioners to their targets without a collision even more technically challenging. We describe how the MOONS fibre positioner control system overcomes those challenges with custom electronics to manage the synchronisation between the positioners, a collision protection system, and a grid driver software system which manages the control of the fibre positioners. We also describe our experiments with different path planning algorithms and present the latest results from MOONS testing.

MOONS is the Multi-Object Optical and Near-IR Spectrograph to be mounted at a Nasmyth focus at the Very Large Telescope. The instrument is equipped with 1000 fibres configured over a field of view of ~500 square arcmin using theta-phi fibre positioning units (FPUs). The MOONS metrology system must accurately determine the position of the fibres in the focal plate, providing fast feedback to the instrument control software during operations. The returned fibre positions can be used for calibrations of the FPUs or fast system recovery after a power loss. If required, the system can also be used for calculating fine adjustments of the fibre positions during acquisition. In this paper, a description of the system design, implementation, and testing in the MOONS focal plate are provided. The presented system has high potential for adaptation to a variety of astronomical instrument applications during integration, testing, and operation stages.

MOONS (Multi-Object Optical and Near-infrared Spectrograph) is a third-generation visible and near-infrared spectrograph for the ESO Very Large Telescope, currently nearing the end of the assembly phase. The three channel spectrograph is fed via a fibre positioning module (FPM) which configures the location of 1001 fibres. The robotic fibre positioning units (FPUs) have been jointly developed by the UK Astronomy Technology Centre (UKATC) and MPS Microsystems (MPS) and provide a high-performance multiplexed focal plane with excellent transmission characteristics. An overview of the as-built mechanisms and supporting infrastructure is presented, with details on the extensive calibration process carried out. The integration process to date will be described, including a discussion of key lessons learned.

MOONS (Multi-Object Optical and Near-infrared Spectrograph) is a third-generation visible and near-infrared spectrograph for the ESO Very Large Telescope currently under construction. The instrument's spectroscopic capabilities are multiplexed via a fibre positioning module (FPM) which configures the location of 1001 fibres. The fibre positioning units (FPUs) have been jointly developed by the UK Astronomy Technology Centre (UKATC) and MPS Microsystems (MPS) to optimise instrument efficiency by providing excellent transmission and an open-loop positioning strategy, allowing a tightly packed focal plane to be rapidly reconfigured. The mechanism geometry enables all positions in the focal plane to be observed in conjunction with a companion sky fibre at close separation. A description of the as-manufactured design and production process of the FPUs is presented, along with a discussion of the performance proven to date, including achievement of the critical pupil alignment and positional repeatability requirements. An overview of the custom testing rig built to automate the characterisation and calibration process is also presented.

The MOONS instrument is a new Multi-Object Optical and Near-infrared Spectrograph for the Very Large Telescope (VLT) . The instrument design aims to deploy nearly 1000 fibers over the field of view requiring to control nearly 2000 actuators by the same number of CAN bus stepper motor drives through 15 independent CAN bus networks. All this massive traffic and extensive wiring can be merged down into a single Ethernet line by means of 3 Ethernet to Multi-CAN Gateways (EtherCAN) and an Ethernet switch. This is possible today due to emerging multi-CAN ARM microcontrollers, which provide highly embedded solutions suited to be located closer to the sensitive areas of the instrument, where power dissipation and space are critical.

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.

The Multi Object Optical and Near-infrared Spectrograph (MOONS) instrument is the next generation multi-object spectrograph for the VLT. This powerful instrument will combine for the first time: the large collecting power of the VLT with a high multipexing capability offered by 1000 optical fibres moved with individual robotic positioners and a novel, very fast spectrograph able to provide both low- and high-resolution spectroscopy simultaneously across the wavelength range 0.64 mu m - 1.8 mu m. Such a facility will provide the astronomical community with a powerful, world-leading instrument able to serve a wide range of Galactic, Extragalactic and Cosmological studies. The final assembly, integration and verification phase of the instrument is now about to start performance testing.

MIRISim is the simulator package for the Mid-Infrared Instrument (MIRI) on the James Webb Space Telescope (JWST). MIRISim simulates photon propagation through MIRI and delivers detector images consistent with the expected on-orbit performance. The simulated data have the same format as the uncalibrated ramp data that will be made available to JWST observers, and include all metadata required for processing with the JWST Science Calibration pipeline. MIRISim was publicly released in 2018 as part of an Anaconda Python environment and is available at www.miricle.org.

After completion of its final-design review last year, it is full steam ahead for the construction of the MOONS instrument - the next generation multi-object spectrograph for the VLT. This remarkable instrument will combine for the first time: the 8 m collecting power of the VLT, 1000 optical fibres with individual robotic positioners and both medium- and high-resolution spectral coverage acreoss the wavelength range 0.65μm - 1.8 μm. Such a facility will allow a veritable host of Galactic, Extragalactic and Cosmological questions to be addressed. In this paper we will report on the current status of the instrument, details of the early testing of key components and the major milestones towards its delivery to the telescope.

The Mid-Infrared Instrument (MIRI) Medium Resolution Spectrometer (MRS) is the only mid-IR Integral Field Spectrometer on board James Webb Space Telescope. The complexity of the MRS requires a very specialized pipeline, with some specific steps not present in other pipelines of JWST instruments, such as fringe corrections and wavelength offsets, with different algorithms for point source or extended source data. The MRS pipeline has also two different variants: the baseline pipeline, optimized for most foreseen science cases, and the optimal pipeline, where extra steps will be needed for specific science cases. This paper provides a comprehensive description of the MRS Calibration Pipeline from uncalibrated slope images to final scientific products, with brief descriptions of its algorithms, input and output data, and the accessory data and calibration data products necessary to run the pipeline.

Astronomical instruments often need simulators to preview their data products and test their data reduction pipelines. Instrument simulators have tended to be purpose-built with a single instrument in mind, and at- tempting to reuse one of these simulators for a different purpose is often a slow and difficult task. MAISIE is a simulator framework designed for reuse on different instruments. An object-oriented design encourages reuse of functionality and structure, while offering the flexibility to create new classes with new functionality. MAISIE is a set of Python classes, interfaces and tools to help build instrument simulators. MAISIE can just as easily build simulators for single and multi-channel instruments, imagers and spectrometers, ground and space based instruments. To remain easy to use and to facilitate the sharing of simulators across teams, MAISIE is written in Python, a freely available and open-source language. New functionality can be created for MAISIE by creating new classes that represent optical elements. This approach allows new and novel instruments to add functionality and take advantage of the existing MAISIE classes. MAISIE has recently been used successfully to develop the simulator for the JWST/MIRI- Medium Resolution Spectrometer.

The Visible and Infrared Survey Telescope for Astronomy (VISTA) is the 4-m wide-field survey telescope at ESO's Paranal Observatory, equipped with the world's largest near-infrared imaging camera (VISTA IR Camera, VIRCAM), with 1.65 degree diameter field of view, and 67 Mpixels giving 0.6 deg(2) active pixel area, operating at wavelengths 0.8-2.3 mu m. We provide a short history of the project, and an overview of the technical details of the full system including the optical design, mirrors, telescope structure, IR camera, active optics, enclosure and software. The system includes several innovative design features such as the f/1 primary mirror, the dichroic cold-baffle camera design and the sophisticated wavefront sensing system delivering closed-loop 5-axis alignment of the secondary mirror. We conclude with a summary of the delivered performance, and a short overview of the six ESO public surveys in progress on VISTA.

A prototype of a scalable and potentially low-cost stacked array piezoelectric deformable mirror (SA-PDM) with 35 active elements is presented in this paper. This prototype is characterized by a 2 μm maximum actuator stroke, a 1.4 μm mirror sag (measured for a 14 mm × 14 mm area of the unpowered SA-PDM), and a ±200 nm hysteresis error. The initial proof of concept experiments described here show that this mirror can be successfully used for shaping a high power laser beam in order to improve laser machining performance. Various beam shapes have been obtained with the SA-PDM and examples of laser machining with the shaped beams are presented.

The JWST Mid Infrared Instrument (MIRI) operates in the 5-28 mu m wavelength range and can be configured for imaging, coronographic imaging, long-slit, low-resolution spectroscopy or medium resolution spectroscopy with an integral field unit. SCASim is one of a suite of simulators which operate together to simulate all the different modes of the instrument. These simulators are essential for the efficient operation of MIRI; allowing more accurate planning of MIRI observations on sky or during the pre-launch testing of the instrument. The data generated by the simulators are essential for testing the data pipeline software. The simulators not only need to reproduce the behaviour of the instrument faithfully, they also need to be adaptable so that information learned about the instrument during the pre-launch testing and in-orbit commissioning can be fed back into the simulation. SCASim simulates the behaviour of the MIRI detectors, taking into account cosmetic effects, quantum efficiency, shot noise, dark current, read noise, amplifier layout, cosmic ray hits, etc... The software has benefited from three major design choices. First, the development of a suite of MIRI simulators, rather than single simulator, has allowed MIRI simulators to be developed in parallel by different teams, with each simulator able to concentrate on one particular area. SCASim provides a facility common to all the other simulators and saves duplication of effort. Second, SCASim has a Python-based object-oriented design which makes it easier to adapt as new information about the instrument is learned during testing. Third, all simulator parameters are maintained in external files, rather than being hard coded in the software. These design choices have made SCASim highly reusable. In its present form it can be used to simulate any JWST detector, and it can be adapted for future instruments with similar, photon-counting detectors.

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.

The Observation Software (OS) is the supervisory software which manages all the exposures and calibrations made by an ESO/VLT instrument. It forms part of the multi-process and multi-layer ESO/VLT instrument software package, receiving astronomer instructions either from a template script or directly from the instrument's graphical user interface. In order to speed up development, ease maintenance and hence decrease the costs of the Observation Software of different instruments (at various sites VLT, VLTI, La Silla, VISTA), a software framework 'Base Observation Software Stub' (BOSS) is supplied by ESO. This article introduces the objectives of the tool collecting the general features of all instrument OS, such is configuration and synchronization of the subsystems, state alignment, exposure and image file handling. The basic structure of the implementation is explained (using design patterns), showing the way the framework copes with a challenge of being constantly adjusted to new generic requirements imposed by the complexity of new instruments, performance requirements, increasing image file size and file numbers, and at the same time remaining backward compatible. The instrument-specific features are illustrated via three of many applications: FLAMES is an example of a complex instrument using a "super OS" controlling three instruments as subsystems: AMBER is a VLTI instrument: and VISTA has high performance requirements on image file handling.

We describe the integration and test phase of the construction of the VISTA Infrared Camera, a 64 Megapixel, 1.65 degree field of view 0.9-2.4 micron camera which will soon be operating at the cassegrain focus of the 4m VISTA telescope. The camera incorporates sixteen IR detectors and six CCD detectors which are used to provide autoguiding and wavefront sensing information to the VISTA telescope control system.