Igor Coretti

ESPRESSO: the Echelle spectrograph for rocky exoplanets and stable spectroscopic observations

ESPRESSO, the Echelle SPectrograph for Rocky Exoplanets and Stable Spectroscopic Observations, will combine the efficiency of modern echelle spectrograph design with extreme radial-velocity precision. It will be installed on ESOs VLT in order to achieve a gain of two magnitudes with respect to its predecessor HARPS, and the instrumental radialvelocity precision will be improved to reach cm/s level. Thanks to its characteristics and the ability of combining incoherently the light of 4 large telescopes, ESPRESSO will offer new possibilities in various fields of astronomy. The main scientific objectives will be the search and characterization of rocky exoplanets in the habitable zone of quiet, nearby G to M-dwarfs, and the analysis of the variability of fundamental physical constants. We will present the ambitious scientific objectives, the capabilities of ESPRESSO, and the technical solutions of this challenging project.

Adoption of new software and hardware solutions at the VLT: the ESPRESSO control architecture case

ESPRESSO is a fiber-fed cross-dispersed echelle spectrograph which can be operated with one or up to 4 UT (Unit Telescope) of ESOs Very Large Telescope (VLT). It will be located in the Combined-Coudé Laboratory (CCL) of the VLT and it will be the first permanent instrument using a 16-m equivalent telescope. The ESPRESSO control software and electronics are in charge of the control of all instrument subsystems: the four Coudé Trains (one for each UT), the front-end and the fiber-fed spectrograph itself contained within a vacuum vessel. The spectrograph is installed inside a series of thermal enclosures following an onion-shell principle with increasing temperature stability from outside to inside. The proposed electronics architecture will use the OPC Unified Architecture (OPC UA) as a standard layer to communicate with PLCs (Programmable Logical Controller), replacing the old Instrument Local Control Units (LCUs) for ESO instruments based on VME technology. The instrument control software will be based on the VLT Control Software package and will use the IC0 Field Bus extension for the control of the instrument hardware. In this paper we present the ESPRESSO software architectural design proposed at the Preliminary Design Review as well as the control electronics architecture.

SOXS control electronics design

SOXS (Son Of X-Shooter) is a unique spectroscopic facility that will operate at the ESO New Technology Telescope (NTT) in La Silla from 2021 onward. The spectrograph will be able to cover simultaneously the UV-VIS and NIR bands exploiting two different arms and a Common Path feeding system. We present the design of the SOXS instrument control electronics. The electronics controls all the movements, alarms, cabinet temperatures, and electric interlocks of the instrument. We describe the main design concept. We decided to follow the ESO electronic design guidelines to minimize project time and risks and to simplify system maintenance. The design envisages Commercial Off-The-Shelf (COTS) industrial components (e.g. Beckhoff PLC and EtherCAT fieldbus modules) to obtain a modular design and to increase the overall reliability and maintainability. Preassembled industrial motorized stages are adopted allowing for high precision assembly standards and a high reliability. The electronics is kept off-board whenever possible to reduce thermal issues and instrument weight and to increase the accessibility for maintenance purpose. The instrument project went through the Preliminary Design Review in 2017 and is currently in Final Design Phase (with FDR in July 2018). This paper outlines the status of the work and is part of a series of contributions describing the SOXS design and properties after the instrument Preliminary Design Review.

BATMAN: a DMD-based multi-object spectrograph on Galileo telescope

Next-generation infrared astronomical instrumentation for ground-based and space telescopes could be based on MOEMS programmable slit masks for multi-object spectroscopy (MOS). This astronomical technique is used extensively to investigate the formation and evolution of galaxies. We are developing a 2048x1080 Digital-Micromirror-Device-based (DMD) MOS instrument to be mounted on the Galileo telescope and called BATMAN. A two-arm instrument has been designed for providing in parallel imaging and spectroscopic capabilities. The field of view (FOV) is 6.8 arcmin x 3.6 arcmin with a plate scale of 0.2 arcsec per micromirror. The wavelength range is in the visible and the spectral resolution is R=560 for 1 arcsec object (typical slit size). The two arms will have 2k x 4k CCD detectors. ROBIN, a BATMAN demonstrator, has been designed, realized and integrated. It permits to determine the instrument integration procedure, including optics and mechanics integration, alignment procedure and optical quality. First images and spectra have been obtained and measured: typical spot diameters are within 1.5 detector pixels, and spectra generated by one micro-mirror slits are displayed with this optical quality over the whole visible wavelength range. Observation strategies are studied and demonstrated for the scientific optimization strategy over the whole FOV. BATMAN on the sky is of prime importance for characterizing the actual performance of this new family of MOS instruments, as well as investigating the operational procedures on astronomical objects. This instrument will be placed on the Telescopio Nazionale Galileo mid-2015.

EVALSO: enabling virtual access to Latin American southern observatories

In the field of observational astrophysics, the remoteness of the facilities and the ever increasing data volumes and detectors poses new technological challenges. As an example, the VISTA and VST wide field telescopes, which are being constructed at the ESOs Cerro Paranal Observatory and will be ready in the next few years, have cameras which will produce after just one year of operation a volume of data that will exceed all the data collected by the VLT since the start of operations in 1999. This sets serious limitations if such large quantities of data must be transferred and accessed in a short time by the participating European Institutions. The EVALSO project, approved by the European Community, addresses these targets in two major ways. It will create a physical infrastructure to efficiently connect these facilities to Europe. This infrastructure will be complementary to the international infrastructure already created in the last years with the EC support (RedCLARA, ALICE, GEANT). Besides this, it will provide the astronomers with Virtual Presence (VP), i.e. the tools to perform and control an astronomical observation from the users site. The main role of INAF - Astronomical Observatory of Trieste (OAT) within the project will be the definition of the architecture, the development of VP system and the integration of a prototype to be used as a demonstrator. This paper will focus on the description of the Virtual Presence system.

Control software and electronics architecture design in the framework of the E-ELT instrumentation

During the last years the European Southern Observatory (ESO), in collaboration with other European astronomical institutes, has started several feasibility studies for the E-ELT (European-Extremely Large Telescope) instrumentation and post-focal adaptive optics. The goal is to create a flexible suite of instruments to deal with the wide variety of scientific questions astronomers would like to see solved in the coming decades. In this framework INAF-Astronomical Observatory of Trieste (INAF-AOTs) is currently responsible of carrying out the analysis and the preliminary study of the architecture of the electronics and control software of three instruments: CODEX (control software and electronics) and OPTIMOS-EVE/OPTIMOS-DIORAMAS (control software). To cope with the increased complexity and new requirements for stability, precision, real-time latency and communications among sub-systems imposed by these instruments, new solutions have been investigated by our group. In this paper we present the proposed software and electronics architecture based on a distributed common framework centered on the Component/Container model that uses OPC Unified Architecture as a standard layer to communicate with COTS components of three different vendors. We describe three working prototypes that have been set-up in our laboratory and discuss their performances, integration complexity and ease of deployment.

Instruments in Grid: the Instrument Element

This work is focused on the interoperability aspects between the Grid and the scientific instrumentation. The IE (Instrument Element) makes possible the monitoring and the remote control of any kind of scientific instrumentation, although the test-bed of this first implementation is constituted of telescopes and related astronomical instrumentation. The first implementation of the IE deals with monitoring aspects; astronomers can remotely interface the telescope and related instrumentation and check the telemetric and scientific data when they are acquired. Future releases of the IE will include extensions, so that remote control capabilities will be also covered.

BATMAN: a DMD-based MOS demonstrator on Galileo Telescope

Multi-Object Spectrographs (MOS) are the major instruments for studying primary galaxies and remote and faint objects. Current object selection systems are limited and/or difficult to implement in next generation MOS for space and groundbased telescopes. A promising solution is the use of MOEMS devices such as micromirror arrays which allow the remote control of the multi-slit configuration in real time. We are developing a Digital Micromirror Device (DMD) - based spectrograph demonstrator called BATMAN. We want to access the largest FOV with the highest contrast. The selected component is a DMD chip from Texas Instruments in 2048 x 1080 mirrors format, with a pitch of 13.68μm. Our optical design is an all-reflective spectrograph design with F/4 on the DMD component. This demonstrator permits the study of key parameters such as throughput, contrast and ability to remove unwanted sources in the FOV (background, spoiler sources), PSF effect, new observational modes. This study will be conducted in the visible with possible extension in the IR. A breadboard on an optical bench, ROBIN, has been developed for a preliminary determination of these parameters. The demonstrator on the sky is then of prime importance for characterizing the actual performance of this new family of instruments, as well as investigating the operational procedures on astronomical objects. BATMAN will be placed on the Nasmyth focus of Telescopio Nazionale Galileo (TNG) during next year.

ESPRESSO instrument control software and electronics: commissioning in Paranal

The ESPRESSO (Echelle SPectrograph for Rocky Exoplanet and Stable Spectroscopic Observations) spectrograph, after the preliminary tests carried out at the Astronomical Observatory of Geneva (Switzerland), has been shipped and re-integrated at the Very Large Telescope (VLT) site in Cerro Paranal (Chile). The instrument control software, designed and developed at INAF–Osservatorio Astronomico di Trieste, had to face several challenges since ESPRESSO is the first instrument placed at the VLT Coud`e Combined Laboratory able to be fed by up to 4 Telescope Units simultaneously (through an incoherent focus), and whose electronics is based on Beckhoff PLCs. Moreover, ESPRESSO requires a careful stabilization of the field image in order to maximize the light flux through the fiber hole, and reach the instrumental radial-velocity precision level of 10 cm/s. These circumstances lead to the development of a few solutions specifically dedicated to ESPRESSO. In this paper we will summarize the features of the ESPRESSO control software, the tests performed during the integration phase in Europe, and discuss the main performances obtained during the commissioning phase and ”first light” observations in Chile

A complete automatization of an educational observatory at INAF-OATs

The Astronomical Observatory of Trieste (OATs), part of the Italian Institute for Astrophysics (INAF), hosts a Celestron C14 telescope, equipped with a robotic Paramount ME equatorial mount, used for public outreach. The telescope is installed inside a dome, recently upgraded with a Beckhoff PLC control system, a SIEMENS inverter for the communication with the motor of the domes roof, and further equipment to allow the complete automatization of the system. A peculiarity of the system is that, when operating, the telescope may exceed the height of the roof: due to this fact the telescope pointing is constrained by the full opening of the roof and, oppositely, the closing of the roof is allowed only when the telescope is in park position. Appropriate sensors are installed to monitor the position of the telescope to properly handle the complete opening or closing of the roof. Several emergency operations are also foreseen, for example in case of bad weather or lost connection with the user. The PLC software has been developed using TwinCAT software. An OPC-UA server is installed in the PLC and allows the communication with a web interface. The web GUI, developed in PHP and Javascript, allows the user to perform the remote operations like switching on all the instrumentations, open the domes roof, park the telescope and view the status of the system. Furthermore through TheSkyX software it is possible to perform the pointing of the telescope and its set up. A dedicated script, interfaced with TheSkyX, have been implemented to perform a complete automated acquisition. An appropriate data storage system is foreseen. All these elements, that cooperate to create a fully remoted controlled system, are presented in this paper.