HARMONI is the first light visible and near-IR integral field spectrograph for the ELT. It covers a large spectral range from 450 nm to 2450 nm with resolving powers from 3500 to 18000 and spatial sampling from 60 mas to 4 mas. It can operate in two Adaptive Optics modes - SCAO (including a High Contrast capability) and LTAO - or with NOAO. The project is preparing for Final Design Reviews. HARMONI is a work-horse instrument that provides efficient, spatially resolved spectroscopy of extended objects or crowded fields of view. The gigantic leap in sensitivity and spatial resolution that HARMONI at the ELT will enable promises to transform the landscape in observational astrophysics in the coming decade. The project has undergone some key changes to the leadership and management structure over the last two years. We present the salient elements of the project restructuring, and modifications to the technical specifications. The instrument design is very mature in the lead up to the final design review. In this paper, we provide an overview of the instrument's capabilities, details of recent technical changes during the red flag period, and an update of sensitivities.
FORS (FOcal Reducer and Low Dispersion Spectrograph), a multi-mode optical instrument mounted on the Very Large Telescope's (VLT) UT1 Cassegrain focus, gets a new look. The upgrade, known as FORS-Up (FORS-Upgrade), is being carried out by ESO and INAF-OATs, and includes, beside replacement of some optical components, the replacement of all the motors, the development of a new calibration unit, the adoption of a new detector, and the design of a control electronics based on the new ELT standards. The refurbishment work has started on the twin spectrograph FORS1, decommissioned in 2009 which was sent to the integration premises of the Astronomical Observatory of Trieste. After resuming the final design of the control electronics, this paper presents the PLC software implementation and the current state of the electronics integration with the new mechanics carried out at INAF-OATs. It also focuses on the ELT-based software and hardware solutions that have been adopted to meet the performance and safety requirements for the motorized functions that control the multiobject spectroscopy blades and the scientific exposure shutter and require customized applications.
KEYWORDS: Equipment, Control software, Spectroscopes, Control systems, Telescopes, Astronomical instrumentation, Telescope instrument control software, Software development
FORS2 (FOcal Reducer/low dispersion Spectrograph) is a multimode (imaging, polarimetry, long slit and multi-object spectroscopy) optical instrument mounted on the Cassegrain focus of the UT1 of ESO’s Very Large Telescope (VLT). Its versatility and large wavelength range (330-1100 nm) make it one of the most requested instruments at the VLT. To keep it operational for at least the next 15 years, the FORS upgrade project (FORS-Up), a collaboration between ESO and INAF-OATs, was started: the twin spectrograph FORS1, decommissioned in 2009, has been sent to Europe and is currently undergoing a complete refurbishment in the integration hall of the Astronomical Observatory of Trieste. Once the upgrade is finished, FORS1 will replace FORS2 at the VLT. In this paper, we report the status of the work currently in progress on the control software: the original one is based on the VLT standards, and it is now being reimplemented within the new ELT (Extremely Large Telescope) software framework. New GUIs have been designed for FORS, which give the user in-depth control over the instrument; new templates for observational, engineering and maintenance procedures have been developed; hardware components have been configured, either as standard devices or as special devices (requiring customized solutions). The upgrade will ensure the continued operation of FORS and represent an invaluable testbed for the new ELT software framework.
The GRAVITY+ project includes the upgrade of the Very Large Telescope Interferometer infrastructure and of the instrument GRAVITY to improve sky coverage, high contrast capabilities, and faint science. The improved sky coverage is obtained via the implementation of one Laser Guide Star (LGS) on each Unit Telescope (UT). This first requires an upgrade of the infrastructure of each of the UTs, which was made over 18 months in 2022 and 2023. The addition of the LGS system requires the implementation of multiple components on several areas of the telescope. These areas include the top ring, the centerpiece, a new platform under the Nasmyth platform, and in the basement. The system includes pointing and aircraft avoidance cameras, the laser projector, laser and electronics cabinets, a heat exchanger, and pumps. As none of the UTs were developed with the infrastructure needed to carry such a system, the same upgrade is made for each of the three UTs. This upgrade consists of a full adaptation of the centerpiece, an upgrade of one of the altitude cable wraps, the installation of a platform under the Nasmyth platform, and the implementation of a cooling circuit running from the basement to the new sub-Nasmyth platform via the azimuth cable wrap. This upgrade requires two missions per telescope, for a total of 30 nights out of operation per telescope. The centerpiece activity also requires the removal of the M1 mirror and cell. The activities were therefore coordinated with the regular recoating of the M1 to minimize the number of nights out of operation. The upgrade required approximately 7.5 staff years of work and 36 missions from Europe to Chile, with around 60 people participating in at least one of the seven missions.
ESO is in the process of upgrading one of the two FORS (FOcal Reducer/low dispersion Spectrograph) instruments – a multi-mode (imaging, polarimetry, long-slit, and multi-object spectroscopy) optical instrument mounted on the Cassegrain focus of Unit Telescope 1 of ESO’s Very Large Telescope. FORS1 was moved from Chile to Trieste, and is undergoing complete refurbishment, including the exchange of all motorised parts. In addition, new software is developed, based on the Extremely Large Telescope Instrument Control Software Framework, as the upgraded FORS1 will be the first instrument in operations to use this framework. The new Teledyne e2V CCD has now been procured and is undergoing testing with the New Generation Controller at ESO. In addition, a new set of grisms have been developed, and a new set of filters will be purchased. A new internal calibration unit has been designed, making the operations more efficient.
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.
HARMONI is the first light, adaptive optics assisted, integral field spectrograph for the European Southern Observatory’s Extremely Large Telescope (ELT). A work-horse instrument, it provides the ELT’s diffraction limited spectroscopic capability across the near-infrared wavelength range. HARMONI will exploit the ELT’s unique combination of exquisite spatial resolution and enormous collecting area, enabling transformational science. The design of the instrument is being finalized, and the plans for assembly, integration and testing are being detailed. We present an overview of the instrument’s capabilities from a user perspective, and provide a summary of the instrument’s design. We also include recent changes to the project, both technical and programmatic, that have resulted from red-flag actions. Finally, we outline some of the simulated HARMONI observations currently being analyzed.
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.
FORS2 is a multi-mode (imaging, polarimetry, long slit and multi-object spectroscopy) optical instrument mounted on the Very Large Telescope (VLT) UT1 Cassegrain focus. It operates in the wavelength range of 330-1100 nm and, with the dismissed FORS1, is one of the most demanded instruments of the VLT in the astronomical community. After many years of operations (FORS1 was one of the first instruments installed at the VLT), an upgrade of the control system is absolutely required. Carried out by ESO and the Astronomical Observatory of Trieste, the upgrade will be applied to the decommissioned FORS1 instrument, that, when fully integrated, will replace FORS2 on the telescope. The upgrade will comprise the replacement of all the motors, the development of a new calibration unit, the adoption of a new ESO detector controller, and the design of a new control electronics based on Beckhoff PLC. Care will be given to the management of the motorized stages, about 50, avoiding MOS (Multi-Object Spectroscopy) slits and focal plane collision problems. The upgraded FORS will also be the first instrument to test the brand new ESO ELT instrument control framework, even if within the VLT environment. This paper will resume the design of FORS control electronics presented at the instrument Final Design Review. The new electronics layout, based on PLCs, and the motor’s control software management will be also described.
NAOMI, the New Adaptive Optics Module for Interferometry is one of the latest additions to the Auxiliary Telescopes of the VLTI system in the Paranal observatory. The changeling task to bring new advanced features was given by the reduced space and wiring restrictions of the current telescope's infrastructure . New cables could not be installed and the exiting ones had slightly different pin-outs for each of the four Auxiliary Telescopes. These complications were overcome by using the CANopen protocol which offers low complexity with minimal wiring and robust noise immunity. Only two wires for data transfer and capable of very low baud-rates (250 k-bit/sec), allowing to use the low-frequency exiting cables. Additionally CANopen brought valuable simplicity to the integration process, like motor control for optical alignment without a PLC, multi-point access to the control bus, transmission quality tests and straightforward Beckhoff PLC integration.
KEYWORDS: Microcontrollers, Error analysis, Software development, Control systems, Telecommunications, Transceivers, Large telescopes, Actuators, Aerospace engineering, Information and communication technologies
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.
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 0.64μm - 1.8μm. 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. Th final assembly, integration and verification phase of the instrument is now about to start performance testing.
Following the arrival of MATISSE, the second-generation of VLTI instrumentation is now complete and was simultaneously enhanced by a major facility upgrade including the NAOMI Adaptive Optics on the Auxiliary Telescopes. On the Unit Telescopes, significant efforts were also made to improve the injection stability into VLTI instruments. On top of GRAVITY's own evolution, its fringe tracker is now being used to allow coherent integrations on MATISSE (the so-called GRA4MAT project). Meanwhile, operations also evolved to be more flexible and make the most of an extended observing parameter space. In this context, we present an overview of the current VLTI performances. Finally, we will report on on-going improvements such as the extension of the longest baselines.
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 near-infrared GRAVITY instrument has become a fully operational spectro-imager, while expanding its capability to support astrometry of the key Galactic Centre science. The mid-infrared MATISSE instrument has just arrived on Paranal and is starting its commissioning phase. NAOMI, the new adaptive optics for the Auxiliary Telescopes, is about to leave Europe for an installation in the fall of 2018. Meanwhile, the interferometer infrastructure has continuously improved in performance, in term of transmission and vibrations, when used with both the Unit Telescopes and Auxiliary Telescopes. These are the highlights of the last two years of the VLTI 2nd generation upgrade started in 2015.
The New Adaptive Optics Module for Interferometry (NAOMI) is ready to be installed at the 1.8-metre Auxiliary Telescopes (ATs) at ESO Paranal. NAOMI will make the existing interferometer performance less dependent on the seeing conditions. Fed with higher and more stable Strehl, the fringe tracker will achieve the fringe stability necessary to reach the full performance of the second-generation instruments GRAVITY and MATISSE. All four ATs will be equipped between September and November 2018 with a Deformable mirror (ALPAO DM-241), a 4*4 Shack– Hartmann adaptive optics system operating in the visible and an RTC based on SPARTA Light. During the last 6 months thorough system test has been made in laboratory to demonstrate the Adaptive Optics and chopping capability of NAOMI.
In this work, mid wavelength infrared microscopy imaging videos of several index finger pads, from voluntary people, are recorded to obtain their thermoregulation curves. The proposed non-invasive technique is able to capture spatial and temporal thermal information emitted from blood vessels under-skin, and the irrigation finger pad system, making possible to capture features that a visual-spectrum microscopy cannot detect. Using an infrared laboratory prepared method several voluntary patients exposed theirs fingers to thermal stress while the infrared data is recorded. Using standard infrared imaging and signal processing techniques the thermoregulation curves are estimated. The Cold/Hot Stress experiments have shown infrared data with exponential trend curves, with different recovering slopes for each voluntary person, and sometimes with two steps increasing slope in one person thermoregulation curve response.
GALACSI is the Adaptive Optics (AO) module that will serve the MUSE Integral Field Spectrograph. In Wide Field Mode it will enhance the collected energy in a 0.2”×0.2” pixel by a factor 2 at 750 nm over a Field of View (FoV) of 1’×1’ using the Ground Layer AO (GLAO) technique. In Narrow Field Mode, it will provide a Strehl Ratio of 5% (goal 10%) at 650 nm, but in a smaller FoV (7.5”×7.5” FoV), using Laser Tomography AO (LTAO). Before being ready for shipping to Paranal, the system has gone through an extensive testing phase in Europe, first in standalone mode and then in closed loop with the DSM in Europe. After outlining the technical features of the system, we describe here the first part of that testing phase and the integration with the AOF ASSIST (Adaptive Secondary Setup and Instrument Stimulator) testbench, including a specific adapter for the IRLOS truth sensor. The procedures for the standalone verification of the main system performances are outlined, and the results of the internal functional tests of GALACSI after full integration and alignment on ASSIST are presented.
On March 17, 2001, the VLT interferometer saw for the first time interferometric fringes on sky with its two test siderostats on a 16m baseline. Seven months later, on October 29, 2001, fringes were found with two of the four 8.2m Unit Telescopes (UTs), named Antu and Melipal, spanning a baseline of 102m. First shared risk science operations with VLTI will start in October 2002. The time between these milestones is used for further integration as well as for commissioning of the interferometer with the goal to understand all its characteristics and to optimize performance and observing procedures. In this article we will describe the various commissioning tasks carried out and present some results of our work.
This paper explores the use of direct drive servos in telescopes applications in the quest of standardization key concepts that might push to more reliable and cheaper solutions for future complex motion systems. Considerations related to different PWM Frequencies, Motor Phasing, position feedback, CAN-bus interfaces, etc. A collection of data from the VLT experience is presented showing the particular needs of the modern telescope’s drives. Can an industry standard amplifier meet the telescope specifications, and therefore be easier to maintain and offer a cheaper solution?
KEYWORDS: Computer programming, Telescopes, Servomechanisms, Amplifiers, Systems modeling, Device simulation, Magnetism, Simulink, Control systems, Head
The large direct drive motors and encoders form together with the control system a high performance telescope exhibiting very high tracking accuracy. This paper describes the integration and fine-tuning of the VLT Drive Systems. It discusses the different problems encountered during the integration. The servo model that was used to simulate the problems and to find new solutions is described as well as test results and advanced analysis methods.
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