HARMONI- The Extremely Large Telescope First Light Integral Field Spectrograph: A Novel Control Architecture to Integrate the Science Instrument Control System with that of Adaptive Optics

Hermine Schnetler, Charlotte Bond, Haresh Chulani, Fraser Clarke, Anne Costille, Graciela Delgado Garcia, Jose Miguel Delgado, Sofia Dimoudi, Andrew Dunn, Elizabeth George, Alberto Estrada Piqueras, Sylvain Guieu, Enrique Joven, Marie Larrieu, Yolanda Martin Hernando, Cecilia Martinez Martin, Saul Menendez Mendoza, Chris Miller, Tim Morris, Arlette PecontalJavier Piqueras Lopez, Luis Fernando Rodriguez Ramos, Joerg Stegmeier, Matthew Townson, Teodora Viera Cuberlo, Thierry Fuscok, David Le Mignant, Benoit Neicheld, Dave Melotte, Matthias Tecza, Niranjan Thatte

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review


HARMONI is the Extremely Large Telescope visible and near infrared integral field spectrograph and will be one of the first light instruments. The instrument supports four operational modes called No Adaptive Optics (NOAO), Single Conjugated Adaptive Optics (SCAO), High Contrast Adaptive Optics (HCAO), and Laser Tomography Adaptive Optics (LTAO). These operational modes are closely related to the wavefront correction topology used to support the performance required for each of the science cases. By following a novel function model-based systems engineering (FBSE) methodology in conjunction with observing the software computer system golden rule of design; namely having tight cohesion within software modules and loose coupling between modules, a system architecture has emerged. In this paper, we present the design of the HARMONI Control System (HCS). Although this is not the first time (for example NACO on VLT and NIRC2 on Keck) that the adaptive optics required to correct the atmospheric turbulence is part of a general instrument design, and not tailored for a very specific science case, this will be the first instrument of this size and complexity in the era of extremely large ground-based telescopes. The instrument control design must be compatible with the ELT instrument control system framework while there is also an expectation that the adaptive optics (AO) real-time computer toolkit (RTC-TK) should be used for the realization of the AO real-time control software and hardware. The HCS is composed of the instrument control electronics (ICE), the Instrument Control System (ICS), and the AO Control Sub-system (AOCS). The operation concept of the instrument is also novel in that for each mode the instrument creates an instantiation of a virtual system composed of only the system blocks required to provide the selected mode of operation. Therefore, each mode supports a unique system composition in terms of hardware, software, and the sequencing of activities.
Original languageEnglish
Title of host publication Modeling, Systems Engineering, and Project Management for Astronomy X
Subtitle of host publicationAt SPIE Astronomical Telescopes + Instrumentation
EditorsGeorge Z. Angeli, Philippe Dierickx
Place of PublicationBellingham, US
ISBN (Electronic)9781510653566
ISBN (Print)9781510653559
Publication statusPublished - 29 Aug 2022
Externally publishedYes
EventSPIE Astronomical Telescopes + Instrumentation 2022: Research for ground- and space-based telescopes, supporting technologies, and instrumentation - Montreal, Quebec, Canada
Duration: 17 Jul 202222 Jul 2022

Publication series

NameProceedings of SPIE
PublisherSPIE - International Society for Optics and Photonics
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


ConferenceSPIE Astronomical Telescopes + Instrumentation 2022
Internet address

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