The active optics software for the VST telescope
Laurent Marty2006
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Abstract
The VST (VLT Survey Telescope) active optics software must basically provide the analysis of the image coming from the wavefront sensor (a 10x10 subpupils Shack Hartmann device) and the calculation of primary mirror forces and secondary mirror displacements to correct the aberrations of the optical system, instrinsic or originated for thermal and gravity reasons. After the telescope commissioning the VST will be operated by ESO. In this framework, INAF-OAC staff was committed to design and realize the software in a VLT-compliant way. This will smoothen the integration, operation and maintenance of the telescope in the Paranal observatory.
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Journal of Instrumentation, 2013
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2001
The VST (VLT Survey Telescope) is a 2.6 m Alt-Az telescope to be installed at Mount Paranal in Chile, in the European Southern Observatory (ESO) site. The VST is a wide-field imaging facility planned to supply databases for the ESO Very Large Telescope (VLT) science and carry out stand-alone observations in the UV to I spectral range. This paper will focus mainly on control software aspects, describing the VST software architecture in the context of the whole ESO VLT control concept. The general architecture and the main components of the control software will be described.
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<title>VLT telescope control software installation and commissioning</title>
Advanced Telescope and Instrumentation Control Software, 2000
Out of the four VLT Unit Telescopes, three have had first light and of those, one is in full scientific operation. So the VLT style Telescope Control Software is in regular operation on three out of four originally foreseen telescopes, and is being installed and tested on the fourth. In fact, it is actually installed and successfully operating on a whole family of ESO telescopes: the NTT, the 3.6m La Silla, the Seeing monitor telescopes on Paranal and La Silla. That means that this software is installed and running on a total of eight telescopes of different kinds, for the moment. The three Auxiliary telescopes of the VLT interferometer and the VLT Survey Telescope, now in the development phase, will join the family. Another member of the family is the Simulation Telescope, called "Control Model", at ESO headquarters in Garching. Although it cannot look at the sky (it is pure electronics and software: no mechanics and no optics) it has been, and still is, of great value. It can be reconfigured to emulate any of the actual telescopes and it is used for off-line testing of new software releases and to analyse and fix problem reports and change requests submitted from observation sites, without disturbing operation. It is also used to test instrumentation software and its interfaces with the TCS before the actual integration at the telescope. This paper presents the actual status of the Telescope Control Software on the VLTs and on the other telescopes. The main focus is in the characteristics that make the TCS architecture portable on very different mechanical and optical configurations. Then the paper concentrates on the strategy used throughout the projects for integration and testing of the modular components. Particular attention is given to the installation and commissioning phases for the VLT telescopes.
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Active Optics System Software Architecture
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The Large Synoptic Survey Telescope (LSST) is an 8-meter class wide-field telescope now under construction on Cerro Pachón, near La Serena, Chile. This ground-based telescope is designed to conduct a decade-long time domain survey of the optical sky. In order to achieve the LSST scientific goals, the telescope requires delivering seeing limited image quality over the 3.5 degree field of view. Like many telescopes, LSST will use an Active Optics System (AOS) to correct in near real-time the system aberrations primarily introduced by gravity and temperature gradients. The LSST AOS uses a combination of 4 curvature wavefront sensors (CWS) located on the outside of the LSST field-of-view. The information coming from the 4 CWS is combined to calculate the appropriate corrections to be sent to the 3 different mirrors composing LSST. The AOS software incorporates a wavefront sensor estimation pipeline (WEP) and an active optics control system (AOCS). The WEP estimates the wavefront residua...
<title>VLT astronomical site monitor: control, automation, and data flow</title>
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Proceedings of SPIE - The International Society for Optical Engineering, 2012
The ESO Adaptive Optics Facility (AOF) will transform UT4 of the VLT into a laser driven adaptive telescope in which the corrective optics, specifically the deformable secondary mirror, and the four Laser Guide Star units are integrated. Three instruments, with their own AO modules to provide field selection capabilities and wavefront sensing, will make use of this system to provide a variety of observing modes that span from large field IR imaging with GLAO, to integral field visible spectroscopy with both GLAO and LTAO, to SCAO high Strehl imaging and spectroscopy. Each of these observing modes carries its specific demands on observing conditions. Optimal use of telescope night-time, with such a high in demand and versatile instruments suite, is mandatory to maintain and even improve upon the scientific output of the facility. This implies that the standard VLT model for operations must be updated to cover these partly new demands. In particular, we discuss three key aspects: (1) the need for an upgrade of the site monitoring facilities to provide the operators with real-time information on the environmental conditions, including the ground layer strength, and their evolution throughout the night; (2) a set of tools and procedures to effectively use these data to optimize the short-term scheduling (i.e. with granularity of one night) of the telescope and (3) the upgrade of the current laser beam avoidance software to better cope with the AOF operational scheme, where the four laser units are continuously operated as long as the atmospheric conditions allow.
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Proceedings of SPIE - The International Society for Optical Engineering
The VST (VLT Survey Telescope) is a 2.6 m class Alt-Az telescope in installation phase at Cerro Paranal in Northern Chile, at the European Southern Observatory (ESO) site. The VST is a wide-field imaging telescope dedicated to supply databases for the ESO Very Large Telescope (VLT) science and to carry out stand-alone observations in the Ultraviolet to Infrared spectral range. The VST is provided with an active optics control system to actively compensate the optical aberrations; it is based on 84 actuators controlling the shape of the primary mirror and a hexapode for secondary mirror positioning. The present paper focuses on the implementation of the microcontroller programming firmware for the Primary Mirror Actuators Electronic Control Board. The most relevant problems encountered during the implementation of this real time multitasking distributed control application are described; optimization problems due to low performing hardware platform, not provided with operating system...
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Integration tests of the VLT Telescope Control System
1997
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VST–VLT Survey Telescope Integration Status
Thinking, Observing and Mining the Universe - Proceedings of the International Conference, 2004
The VLT Survey Telescope (VST) project started in 1997 at OAC with the aim of promoting the design and construction of a 2.6 m aperture, wide-field (1°×1°), UV to I facility, to be installed and operated at the European Southern Observatory (ESO) on the Cerro Paranal Chile. VST was primarily intended to complement the observing capabilities of VLT with wide-angle imaging for detecting and precharacterising sources for further observations with the VLT.But the VST was also thought for non-VLT related stand-alone survey projects. The paper will report actual project development status during integration phase in progress.
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