In progress – view active session
Conference 13094
Ground-based and Airborne Telescopes X
16 - 21 June 2024 | Room G403/404, North - 4F
View Session 
Session 1:
Enclosures
16 June 2024 • 10:10 - 11:50 Japan Standard Time | Room G403/404, North - 4F
Session Chairs:
Trupti Ranka, GMTO Corp. (United States), Frank W. Kan, Simpson Gumpertz & Heger Inc. (United States)
13094-1
16 June 2024 • 10:10 - 10:30 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The Giant Magellan Telescope (GMT), one of 3 planned extremely large telescopes (ELT), will have a 25.4-meter diameter effective aperture, and will be located on the summit of Cerro Las Campanas in Chile. Here we discuss the latest GMT site master plan, and designs for the site infrastructure, telescope enclosure, and support facilities. In late 2021, GMTO selected IDOM (Bilbao, Spain) to take the preliminary enclosure reference design through to final design and construction documents (drawings and specification). Over the last 2 years, all aspects of the enclosure design, including structures, mechanisms, pier seismic isolation system, and control systems, have been refined as they passed through a 60% critical design review (CDR) in 2023 and the final design review (FDR) in May 2024. We discuss the Building Information Modeling (BIM) approach for the enclosure, application of dynamic 3D models for visualizations, use of a Building Automation System (BAS) for managing access, security, audio/video monitoring, lighting, HVAC, and related functions. Major work at the GMTO site started in 2015, and here we discuss the latest plans for construction.
13094-2
16 June 2024 • 10:30 - 10:50 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The Sloan Digital Sky Survey V (SDSS-V) Local Volume Mapper (LVM) is an ultra-wide field high spatial
resolution IFU survey of the Milky Way, the Magellanic Clouds, and a sample of galaxies in the local volume.
Observations are carried out with the LVM Instrument (LVM-I), a specially designed robotic telescope, instrument,
and facility located at Las Campanas Observatory (LCO) in Chile. The LVM-I is hosted in a custom-built
roll-off type enclosure that protects the hardware, allows for simultaneous observations towards different directions
in the sky by the four LVM-I telescopes, provides a thermally controlled stable and clean environment
for the LVM-I spectrographs, supplies all necessary utilities (e.g. power, communications, LN2 detector cooling)
to the different LVM-I sub-systems, provides environmental telemetry and information, and integrates with
the LVM-I control software to operate in an automated fashion. In this paper we discuss the design of the
LVM-I enclosure, its construction, and an evaluation of its performance.
13094-3
16 June 2024 • 10:50 - 11:10 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
Rubin Observatory Dome was designed and built by EIE Ground Technologies Srl - Company of EIE GROUP with headquarters in Venice-Mestre, Italy. The Design Phase was completed in February 2016. On-site activities started in the spring of 2017. The Dome is approaching the final completion of testing and integration.
The Dome utilizes a steel structure. This supports a bi-parting, two door aperture, a uniquely designed moving Light Windscreen, a Light Baffled Louver System, an overhead bridge crane, a rear access door and numerous platforms. In this paper, we present the status of the final assembly, integration and testing.
13094-4
16 June 2024 • 11:10 - 11:30 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The GMT enclosure detail engineering design has been consolidated to confidently face the future construction phase. This final detailed design phase has focused on delivering a cost-effective reliable enclosure that can be efficiently built in Las Campanas remote location providing a resilient integrated system that will house and protect GMT telescope against adverse environmental and seismic conditions. A seamless integration of a wide variety of disciplines including concrete and steel structures, mechanisms, mechanical-electrical-plumbing (MEP), telescope specific utilities, control systems and architectural has been vital to comply with the strict requirements of the project.
Besides, a thorough validation plan has been produced comprising analytical verification, early prototypes, factory and site assembly and testing plans (FAT & SAT), to guarantee performance and reliability of all subsystems at the site. Furthermore, construction procedures, techniques and logistics have been reviewed and considered when developing design key features together with assembly specifications so that the enclosure is constructed at the site in a safe and effective manner.
13094-5
16 June 2024 • 11:30 - 11:50 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The telescope Main Structure and the Dome of the ELT are being procured by ESO as an integrated system together with the auxiliary building and the service plants and are supplied by the ACe Consortium. The contract was signed in May 2016 and despite various challenges and obstacles – commercial, technical, and other – the progress that has been achieved to date is significant and tangible. Both the Dome (including Auxiliary Building) and the Telescope Structure have passed Final Design Review; manufacture of the structural elements is approaching completion; the first mechanisms have been tested and delivered to site; and the publicly available footage of the construction speaks for itself.
In this paper we will describe the advancement reached by the project and discuss some technical aspects associated to the design.
Break
Lunch Break 11:50 - 13:10
Session 2:
Mounts
16 June 2024 • 13:10 - 14:50 Japan Standard Time | Room G403/404, North - 4F
Session Chairs:
Sandrine J. Thomas, Vera C. Rubin Observatory (United States), Jason Spyromilio, European Southern Observatory (Germany)
13094-6
16 June 2024 • 13:10 - 13:30 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The DAG (Dogu Anatolu Gözlemevi) Eastern Anatolia Observatory is provided with a 4m-class optical and infrared telescope. Since 2015, the project has seen the crucial contribution of EIE GROUP in the Design, Production and on-site Installation of the mount structure, in contract with AMOS company. . Now, on-site assembly activities have been completed. This document focuses on the on-site assembly activities of the EIE Group, as well as the related internal pre-commissioning, commissioning, and functional and acceptance tests.
13094-7
16 June 2024 • 13:30 - 13:50 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
National Astronomical Observatory of Japan (NAOJ) is responsible for procuring the Telescope Structure System (STR) of the Thirty Meter Telescope (TMT) and engaged Mitsubishi Electric Corporation (MELCO) to conduct the preliminary/final design and pre-production work since 2012. The final design was successfully matured through the multiple design reviews covering mechanical, controls, auxiliary systems like the Segment Handling System (SHS), Aerial Service Platform (ASP), Elevator (ELV), safety, and the seismic isolation system. TMT STR is currently is the pre-production phase and already passed the pre-production reviews for major rotating mechanical structures. In this paper, we present the design overview of the TMT STR and current programmatic status.
13094-8
16 June 2024 • 13:50 - 14:10 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The Vera C. Rubin Observatory is an integrated survey system, currently under construction in Chile, to accomplish a 10-year optical survey of the southern sky. The 8.4m Simonyi Survey Telescope mount is nearing completion and undergoing final verification and performance testing. Since the system is optimized for etendue, the telescope mount slewing performance is particularly critical to overall survey efficiency. For example, this high performance mount is capable of slewing 3.5 degrees in a 3-second period. An overview of the mount subsystems is presented and selected dynamic performance results from on-site testing are described.
13094-9
16 June 2024 • 14:10 - 14:30 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The Giant Magellan Telescope (GMT) Mount is the structural, mechanical, hydraulic, and electronic system that provides the overall framework for mounting and alignment of optics and science instruments, supports payloads and utilities, and provides the three main axes of motion consisting of azimuth, elevation, and Gregorian Instrument Rotator (GIR) rotations. The GMTO Corp. has selected OHB Digital Connect and Ingersoll Machine Tools to supply the final design, fabrication, and installation of the GMT Mount. The Final Design Review of the Mount subsystem was successfully passed in June 2023. The first phase of fabrication has begun starting with the Azimuth Track Segments. This paper will describe the final design configuration of the Mount, major subassemblies, fabrication and test phasing, fabrication highlights to-date, and an overview of the prototype testing that validated the final design parameters.
13094-10
16 June 2024 • 14:30 - 14:50 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The Giant Magellan Telescope mount is under design and development at OHB Digital Connect since 2019. It passed final design review in June 2023. To fulfill the challenging accuracy and functionality requirements, complex design solutions needed to be developed. In order to support and validate the design of those subsystems and to provide reliable data and parameter for performance analysis, a variety of prototyping tests have been performed during the design phase on critical subsystems like support interface to the concrete foundation, the earthquake damping system , the hydrostatic bearings and direct drive system. Optimization of vibration sources like cable wraps and electronic cabinets have been done supported by tests. The covers of the primary mirrors with a diameter of more than eight meters were developed and tested in full scale. The presentation provides an overview on the main subsystem development test activities and shows test setups and results of the main prototyping tests supporting the subsystems design and analyses.
Break
Coffee Break 14:50 - 15:20
Session 3:
Observatory Upgrades & Repairs
16 June 2024 • 15:20 - 17:40 Japan Standard Time | Room G403/404, North - 4F
Session Chair:
Tomonori Usuda, National Astronomical Observatory of Japan (United States)
13094-11
16 June 2024 • 15:20 - 15:40 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The DKIST Enclosure Azimuth Mechanism is responsible for accurate positioning of the Enclosure in azimuth and provides a second degree of freedom to the altitude movement of the Enclosure Shutter which enables an overall position accuracy of 19 arcmin point-to-point at the Enclosure Aperture. The mechanism is primarily comprised of sixteen track rail segments, eight driven bogies, and two idler bogies, and it serves as the interface between the fixed support building Ring Girder structure and the rotating Enclosure structure. Visual observations and control system torque data have shown evidence of a loss of contact at the interface between the individual bogie wheels and the track rail sections. As a result, a project was initiated to improve the overall flatness of the azimuth track rails to improve performance of the Enclosure and reliability of the mechanism components.
13094-12
16 June 2024 • 15:40 - 16:00 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
Ground-based telescope observatories are typically located in harsh environments. Due to their location, they are subject to a wide range of severe environmental conditions such as seismic events, strong winds and large diurnal temperature swings including freeze/thaw cycles. It is common for telescope observatories to experience fatigue and degradation as a result of their unique dynamic use within these harsh environmental conditions. One specific result of this degradation includes rainwater leakage into the rotating telescope enclosure. This water leakage has the potential to cause serious damage to interior components of the telescope enclosure, including the telescope and its sensitive instruments. Using the 8.2-meter Subaru Telescope on Maunakea in Hawaii as a case study, this paper will present innovative and traditional techniques for detection of rainwater leakage into the rotating telescope enclosure and other sensitive areas.
13094-13
16 June 2024 • 16:00 - 16:20 Japan Standard Time | Room G403/404, North - 4F
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In this paper, a kinetic energy recovery system for large telescopes is presented, with the Atacama Large Aperture Submm Telescope (AtLAST) as a possible target application. The system consists of supercapacitors integrated in the DC-link of motor inverters through a bidirectional DC-DC converter. The optimal system design, based on the energy flow analysis within the telescope's power electronics, is introduced. The proposed system is simulated as part of the telescope's drives, providing not only a significant reduction in energy consumption of the telescope due to motion, but also remarkably reducing (or shaving) grid power peaks. We find that the system presented here can contribute to making both current and future observatories more sustainable.
13094-14
16 June 2024 • 16:20 - 16:40 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
Each of the Keck telescopes incorporates a 3” thick layer of grout which serves as the primary load path between the steel azimuth journal and the main body of the reinforced concrete pier. Keck has observed increased journal deflections of the Keck 1 telescope under load, affecting performance. Investigation into the source of the deflections found deterioration of the cementitious grout, which is believed caused by a combination of exposure to oil and cyclic loading from the telescope.
The JPL team responsible for the Deep Space Network antennas solved a comparable issue by changing from a cementitious grout to an oil impervious epoxy grout, so a similar approach was investigated at Keck.
This paper presents: 1) Background and history. 2) Material qualification testing of the replacement epoxy grout. 3) Procedural validation leading up to a trial repair of a 16 degree section of the Keck 1 pier. 4) Lessons learned from the trial repair which occurred in October 2023—including preliminary performance monitoring, as available. The potential for material creep is a specific topic of interest.
13094-15
16 June 2024 • 16:40 - 17:00 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The Greenland Telescope (GLT) currently achieves a blind pointing
accuracy of 2 arcseconds rms, sufficient for 230 GHz VLBI operations
at Pituffik Space Base. Plans to relocate the antenna to Summit
Station are underway to enable observations at >=690 GHz, which
requires improving pointing accuracy due to smaller beam sizes at
higher frequencies. Since achieving the ALMA-standard referenced
pointing accuracy of less than 1 arcsecond for single-dish operations
is impractical due to limited sensitivity, GLT's strategy involves
real-time adjustments using data from metrology sensors, following
the Systematic Pointing Error Model (SPEM) by the antenna manufacturer
(Vertex Antennas). This paper highlights our metrology system's
role in predicting pointing corrections through real-time monitoring
of inclinometers, linear, and temperature sensors. Additionally,
we introduce a night-viable optical guidescope system for astrometric
referencing of star-fields, aiming to enhance pointing precision
for high-frequency VLBI with the GLT.
13094-16
16 June 2024 • 17:00 - 17:20 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
In October 2022, there was an accident with Gemini North Primary Mirror (M1) during routine mirror movements that caused it to come in contact with its washcart. The M1 came into contact with an earthquake restraint on the washcart as it was being moved in preparation for stripping and recoating activities. After the incident, analyses were conducted to determine the extent of the damage and the necessary steps to restore the telescope to normal operations. This paper provides detailed explanations how the Gemini North telescope was returned to normal operations.
13094-17
16 June 2024 • 17:20 - 17:40 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
During the last SPIE congress, SENER presented a novel concept of a system for cleaning of optical surfaces, initially conceived for ground-based astronomical observatories.
The proposed concept is based on laser cleaning, a technology broadly used in industrial application, which has been carefully adjusted to gently cleaning the mirror while guarantee the integrity of the coating and, even more important, the substrate.
This paper reports the obtained results during the system tests and presents the conclusions and summarises the following steps in the product development.
Monday Plenary
17 June 2024 • 08:20 - 10:00 Japan Standard Time | National Convention Hall, 1F
View Full Details: spie.org/AS/monday-plenary
13173-500
Moving TMT forward: Japan’s contributions and transformative approach toward community engagement
(Plenary Presentation)
17 June 2024 • 08:30 - 09:15 Japan Standard Time | National Convention Hall, 1F
Show Abstract +
The Thirty Meter Telescope International Observatory (TIO) is an ambitious international scientific endeavor. In Part 1, we highlight Japan’s contributions toward technical advancements. Building upon the scientific and engineering success of the Subaru Telescope and ALMA, Japan leads in developing the telescope structure, primary mirror production, and cutting-edge science instruments. Part 2 delves into TIO’s transformative shift toward community engagement. At TIO, we believe in community model of astronomy that upholds the values of inclusion, respect, and community stewardship. We are committed to listening to, learning from, and working together with Hawaiʻi commuities to build a brighter future for all.
13173-501
From dark skies to bright futures: the evolution of astronomy in Africa and the hosting of the historic International Astronomical Union General Assembly 2024
(Plenary Presentation)
17 June 2024 • 09:15 - 10:00 Japan Standard Time | National Convention Hall, 1F
Show Abstract +
Africa's unique dark skies offer vast potential for astronomy, which has significantly advanced over the last two decades through substantial investment in infrastructure and human capital. The African Astronomical Society (AfAS), relaunched in 2019, plays a crucial role in this ascent, enhancing the network of astronomers across the continent, fostering research collaborations, and advising on policy. Noteworthy achievements for Astronomy in Africa include securing a bid to host the mid-frequency component of the Square Kilometre Array (SKA) telescope, hosting the first International Astronomical Union (IAU) General Assembly in Africa in August 2024, and being home to the IAU Office of Astronomy for Development (OAD) since 2011. This talk highlights these milestones, illustrating the community's commitment to developing astronomy on the continent and utilising astronomy as a tool to address developmental challenges.
Break
Coffee Break 10:00 - 10:20
Session 4:
Observatory Construction Updates
17 June 2024 • 10:20 - 12:30 Japan Standard Time | Room G403/404, North - 4F
Session Chair:
Bruce C. Bigelow, GMTO Corp. (United States)
13094-18
Vera C. Rubin Observatory construction status
(Invited Paper)
17 June 2024 • 10:20 - 10:50 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
Vera C. Rubin Observatory is the combination of a 8.4-m telescope, a 3.2 gigapixels camera and a sophisticated data pipeline and it is now in the final stage of construction/commissioning in Chile. In the last couple of years, every single part of the observatory has gone through tremendous progress. The telescope is fully populated with its components except for the glass mirrors and moving, the LSSTCamera is undergoing final performance testing before being shipped to Chile and the data pipeline is ready to receive and reduce the first on-sky images. Meanwhile, the Education and Public Outreach team has paved the way to operations by successfully finishing construction and started implementing their full program.
13094-19
The Cherenkov Telescope Array Observatory (CTAO): ongoing development of the world’s premier ground-based gamma ray observatory
(Invited Paper)
17 June 2024 • 10:50 - 11:20 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The Cherenkov Telescope Array Observatory (CTAO) is the next generation ground-based observatory for gamma-ray astronomy at very high energies. The CTAO is entering the construction phase of the project, and the development of telescopes and observatory infrastructure is already underway. With an expected completion later this decade, the CTAO will be an order of magnitude more sensitive, have a wider field of view, and have unprecedented accuracy detecting high-energy gamma rays compared to existing smaller observatories. With both northern (La Palma, Canary Islands) and southern (Paranal, Chile) sites, the CTAO will provide full sky coverage over energies from 20 GeV to 300 TeV. Efforts on all major subsystems are progressing, with designs based on prototypes or operational heritage, and we will begin operating the first accepted telescopes in 2025.
13094-20
Construction update for the Square Kilometre Array Observatory
(Invited Paper)
17 June 2024 • 11:20 - 11:50 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The Square Kilometre Array Observatory will be the world's largest radio telescope facility and will operate across the frequency range of 50 MHz to 15.4 GHz through a pair of interferometric arrays, SKA-Low (Australia; 50-350 MHz) and SKA-Mid (South Africa; 350 MHz - 15.4 GHz).
With the construction approved in July 2021, and permitting access provided to both sites by December 2022, we report on the infrastructure development, manufacturing, early integration activities and initial array deployments. We highlight the progress against the planning and the trajectory for completion across the budget, schedule and performance baselines.
We note the challenges encountered and navigated in the execution of large research infrastructure construction as well as the broader impacts for such investments, beyond the planned scientific research.
13094-21
17 June 2024 • 11:50 - 12:10 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The Dynamic REd All-sky Monitoring Survey (DREAMS) is a near-infrared fully automated all-sky survey that will be conducted using a custom built 0.5m telescope that will be located at the Australian National University’s Siding Spring Observatory. The telescope feeds 6 individual InGasAs cameras spanning a total field-of-view of 3.8sq.deg using a novel optomechanical design.
Here we present the finished details of the telescope construction and its measured performance as well as details of the survey it will perform of the Southern transient sky.
13094-220
17 June 2024 • 12:10 - 12:30 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
We are carrying out a 1.8-m aperture off-axis telescope project PLANETS. The PLANETS telescope is characterized by using an off-axis mirror to enable us high-contrast imaging and spectroscopy with low-scattering in the optical system. Our major scientific goal is to observe faint emission around a bright body, such as gases surrounding planets and satellites in the solar system (e.g., Europa’s water plume) as well as exoplanets. Using a new technology of mirror polishing with a robot arm and 3-point drag probe, we performed the final polishing of the off-axis primary mirror. We also developed the whiffletree support with warping harness for the primary mirror support. We will assemble the whole PLANETS telescope system and conduct the first light of stars as technical demonstration in Japan within a year. We have begun coordinating with several high-altitude observatory sites in which the PLANETS telescope will be installed after the technical demonstration in Japan.
Break
Lunch Break 12:30 - 14:00
Session 5:
Modeling as a Driver of Observatory Design - Joint Session with 13094 and 13099
17 June 2024 • 14:00 - 16:50 Japan Standard Time | Room G403/404, North - 4F
Session Chairs:
Breann N. Sitarski, NASA Goddard Space Flight Ctr. (United States), Bernhard Lopez, Cherenkov Telescope Array Observatory gGmbH (Germany)
13094-25
17 June 2024 • 14:00 - 14:20 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The National Science Foundation’s Daniel K. Inouye Solar Telescope (DKIST) is the largest solar telescope in the world, utilizing a 4-m off-axis primary mirror. The resulting mount size, long optical pathways, various moving components, and complex thermal design leaves DKIST with a very tight optical error budget that is susceptible to vibration-related degradation. There has been an ongoing survey to identify and address vibration sources affecting the optical path of the telescope during DKIST construction and operations. Improvements in this effort within the last year have enabled us to distinguish and categorize several vibration sources, in order to prioritize solutions for those with the highest impact on image motion. Presented herein are recent examples of sources with significant impact, including the details on how we tracked and identified them, and the solutions that were implemented in order to reduce jitter. As DKIST continues operations, future vibration mitigation efforts will be supported by additional data from other instruments in order to identify opportunities for optimization and further isolate localized vibration within our optics systems.
13094-26
17 June 2024 • 14:20 - 14:40 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
External environmental conditions lead to thermal deformations of the primary reflector of the 50-m diameter Large Millimeter Telescope Alfonso Serrano (LMT). This paper describes efforts to improve the night-time performance of the telescope at millimeter-wavelengths and allow extension of scientific observations into daylight hours, using the LMT's active surface to counteract the effects of thermal gradients within the antenna structure. Several approaches to stabilizing the LMT’s thermal behavior will be described, including operation of a ventilation system in the antenna backup structure and a real-time metrology system to measure and correct large-scale, thermally induced, surface deformations.
13094-27
17 June 2024 • 14:40 - 15:00 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
Computational Fluid Dynamics and conjugate heat transfer models have been developed and/or updated to validate thermal requirements for the TMT International Observatory enclosure Heating, Ventilation and Air Conditioning system, azimuth and cap drive systems, interstitial space volume, as well as the Summit Facilities tunnel, mechanical room, utility room, and chiller exhaust. The resulting thermal environment is assessed and linked to performance, wherever applicable.
13094-28
17 June 2024 • 15:00 - 15:20 Japan Standard Time | Room G403/404, North - 4F
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The Dominion Radio Astrophysical Observatory’s John A. Galt 26 m radio telescope serves multiple roles for the Canadian radio astronomy community. The attributes of this telescope make it ideal for spectropolarimetric studies of the interstellar medium, however instrumental conversion of unpolarized radiation into a polarized signal can corrupt the astronomical signal as the telescope undergoes various loading conditions.
To characterize these effects, a finite element (FE) model of the telescope was constructed, based on available blueprints and supplemented by manual measurements. To validate this FE model, vibration measurements were conducted over four days in September 2022 by NRC-Herzberg engineers. The telescope was instrumented with accelerometers, and vibrations were excited using the step-release and impulse hammer methods. This paper will briefly review the model development and analytical predictions, will describe the instrumentation plan and experimental approach used, and will summarize key results from these tests, in particular the first several vibration modes of the telescope.
Coffee Break 15:20 - 15:50
13099-28
17 June 2024 • 15:50 - 16:10 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
Leighton Chajnantor Telescope (LCT) will be moved to the new site at Chajnantor Plateau, Chile in 2024. The new site has high wind speed and large temperature difference, which leads to strong wind disturbance and beam offset for LCT due to the deformation of the primary reflector. To achieve a high pointing control accuracy, we propose a composite feedforward/feedback control policy (CFFCP), which integrates disturbance observer-based feedforward control policy (DOB-FFCP) and the robust feedback control policy (RFBCP) to compensate the wind disturbance and the beam offset compensation strategy (BOCS) to reduce the negative effect caused by the beam offset respectively. The results of simulation on the synthesized model of LCT’s pointing control system reveal that the proposed CFFCP can signific antly reduce the pointing error during the observations.
13099-29
17 June 2024 • 16:10 - 16:30 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The integrated modeling group at GMTO maintains a detailed FE model (mesh) of the entire telescope from foundation to top-end. Representations derived from this model are a very important component of simulations studying the effects of vibrations and misalignments due to wind, gravity, temperature variations, drives, actuators, utilities, and instruments on the image formation process.
13099-30
17 June 2024 • 16:30 - 16:50 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
Self-induced vibrations along with wind-induced jitter are considered as most limiting factors for the performance of the Giant Magellan Telescope (GMT). The status of dynamic analysis in context of the latest GMT mount de-sign activities is reported. Particular attention is paid to the vibration error budget, which is used to manage active disturbances to meet demanding tracking performance requirements. The vibration budget is based on tracking simulation results combined with contributions from different jitter and vibration sources such as drives, utility wraps, cabinets, and many other subsystems. The Mount Transfer Function (MTF) concept as an important tool for analysis of vibration paths from the source to the image motion is introduced and its application in several use cases with both modeled and measured disturbances is illustrated.
Tuesday Plenary
18 June 2024 • 08:30 - 10:00 Japan Standard Time | National Convention Hall, 1F
View Full Details: spie.org/AS/tuesday-plenary
13173-502
The present and future of Japan's space program
(Plenary Presentation)
18 June 2024 • 08:30 - 09:15 Japan Standard Time | National Convention Hall, 1F
Show Abstract +
The Basic Plan on Space Policy sets forth the basic principles of Japan's space policy with an aim to promote policies for space development. The latest version, approved by the Cabinet in June 2023, marks a significant shift by defining space science as a crucial integral part of Japan's space development efforts, transitioning from treating it solely as an isolated academic activity. For instance, the Artemis program is promoted as a policy initiative where scientific exploration is positioned to serve a precursor role. It also encourages Japan’s involvement in NASA's post-JWST efforts. Here, I will present Japan's recent accomplishments and future plans in space science.
13173-503
NASA astrophysics: from today to the Habitable Worlds Observatory
(Plenary Presentation)
18 June 2024 • 09:15 - 10:00 Japan Standard Time | National Convention Hall, 1F
Show Abstract +
The goals of the Astrophysics Division are to understand how the universe works, understand how we got here and to address the question, are we alone? In this talk, Dr. Clampin will discuss the current goals of the Astrophysics Division, and its suite of current and future missions. He will also preview progress towards the 2020 National Academies (NAS) Decadal Survey including the key recommendation, the Habitable Worlds Observatory and NASA’s approach to its implementation. Dr. O’Meara will discuss the first steps towards implementation, the formation of a Science, Technology, Architecture Review Team (START) and Technical Analysis Group (TAG) for HWO. He will describe how these teams, along with a large cohort of volunteers are working to define the trade space that must be explored for HWO to meet its top science goals of surveying exoplanets for the signatures of life and performing transformational astrophysics.
Break
Coffee Break 10:00 - 10:30
Session 6:
Commissioning
18 June 2024 • 10:30 - 12:50 Japan Standard Time | Room G403/404, North - 4F
Session Chair:
Tomonori Usuda, National Astronomical Observatory of Japan (United States)
13094-29
18 June 2024 • 10:30 - 11:00 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
TAO is a project to build and operate a 6.5m telescope at the summit of Co. Chajnantor. The enclosure passed its rotation test and will be completed at the beginning of 2024. The summit operation building has been completed. The telescope mirrors and mount has already arrived in Chile. The preparation of the instruments are also in-progress, The first light instruments, NICE and MIMIZUKU, are waiting for the transportation from Japan to Chile. SWIMS has returned back from Hawaii to Japan for upgrading. Development of a new optical camera has also started. TAO will use approximately 45% of its scientific observation time as project time, 35% as Japan open time for the Japanese community, and 10% as Chilean time for the Chilean community. 5-15% will be provided as paid observing time.
13094-30
The CCAT project nearing first light: updates on the facility, instrumentation, and science
(Invited Paper)
18 June 2024 • 11:00 - 11:30 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
We report on the progress of the CCAT-prime Project: the Fred Young Submillimeter Telescope (FYST), its instrumentation and the associated science program. The FYST system is optimized for wide-field high surface brightness sensitivity in the submillimeter to millimeter-wave telluric windows. Our science program ranges from constraining fundamental properties of the Universe with high frequency CMB polarization studies through studies of reionization, galaxy and structure formation with line-intensity mapping, submillimeter continuum studies and the Sunyaev-Zel’dovich effect to revealing the physics of star formation in the Galaxy through large field, high frequency velocity-resolved spectroscopy and wide-field submillimeter dust polarization studies. These and other studies are enabled by wide-field polarimetric cameras, broad-band imaging spectrometers and heterodyne receiver arrays. FYST first light is expected in early 2025.
13094-31
18 June 2024 • 11:30 - 11:50 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The National Science Foundation’s (NSF’s) Daniel K Inouye Solar Telescope (DKIST) is the largest solar telescope in the world; it has and continues to provide the sharpest views ever taken of the solar surface. The telescope has a 4m aperture primary mirror, however, due to the off-axis nature of the optical layout, the telescope mount, enclosure, and observatory have proportions similar to an 8-metre class telescope.
This paper provides an overview and discussion of the integration phase of the construction project and the first years of the operations phase. The paper’s perspective is that of the site-based team coordinating the integration schedule and subsequently the Technical site operations in the operations period. The challenges from logistical, management, and technical perspectives will be highlighted along with strategies that worked and those that did not. Also where appropriate there will be discussion on what would be done differently.
13094-32
18 June 2024 • 11:50 - 12:10 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
Three small aperture telescopes (SATs) of Simons Observatory, located at an elevation of 5,200 m in the Atacama Desert in Chile, are designed specifically to target the cosmic microwave background B-mode polarization pattern from primordial gravitational waves. The SATs incorporate over 30,000 transition-edge sensor (TES) bolometers in six spectral bands centered between 27 and 280 GHz. The three SATs were deployed at the site successively from mid 2023 to early 2024 and commissioning has started. In this work, we present an overview of key technologies of the SO SATs . We also report on the current status of the SATs and highlight results in the commissioning observations.
13094-33
18 June 2024 • 12:10 - 12:30 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The ASTRI Mini-Array is a collaborative international effort led by the Italian National Institute for Astrophysics (INAF) to develop, build and operate a facility of nine Imaging Atmospheric Cherenkov Telescopes of the four meters class to study astronomical sources emitting very high energy gamma-rays in the TeV spectral band. The Array is currently under construction on the island of Tenerife at the Observatorio del Teide based on a host agreement with the Instituto de Astrofisica de Canarias.
In this paper we report on the on the results of the opto-mechanical characterization of ASTRI-1, the first telescope of the ASTRI Mini-Array installed at the site.
13094-34
18 June 2024 • 12:30 - 12:50 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
As the main observational facility of Center for the Gravitational-Wave Universe at Seoul National University, the 7-Dimensional Telescope (7DT) is a multi-telescope system designed to identify electro-magnetic (EM) counterparts of gravitational-wave (GW) sources. Consisting of 20 50-cm telescopes along with 40 medium-band filters of 25-nm full width at half maximum, 7DT can obtain spectral mapping images for a large field of view (~1.25 square degrees). This multi-object spectral imaging capability along with flexible operation, real-time data reduction and analysis enable 7DT to follow up GW events quickly and to discover EM counterparts with unmatched efficiency. 12 of the 20 planned telescopes are deployed at El Sauce Observatory located at Rio Hurtado Valley in Chile. Since we obtained the first light of 7DT in October 2023, we started its commissioning procedures including examination of bias levels, master flat production, and spectrophotometric standardization. In this talk, we present details of instruments and their set-up, commissioning procedures and data characteristics of 7DT along with our three-layered surveys which are assumed to initiate in early 2024.
Break
Lunch/Exhibition Break 12:40 - 13:50
Session 7:
Commissioning & Ops I
18 June 2024 • 14:00 - 15:40 Japan Standard Time | Room G403/404, North - 4F
Session Chair:
Jean-Gabriel Cuby, Lab. d'Astrophysique de Marseille (United States)
13094-35
The US National Science Foundation Daniel K. Inouye Solar Telescope: operations commissioning: results and lessons learned
(Invited Paper)
18 June 2024 • 14:00 - 14:30 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The National Science Foundation’s 4m Daniel K. Inouye Solar Telescope (DKIST) on Haleakala, Maui is the largest solar telescope in the world. DKIST’s superb resolution and polarimetric sensitivity will enables astronomers to explore the origins of solar magnetism, the mechanisms of coronal heating and drivers of flares and coronal mass ejections. DKIST operates as a coronagraph at infrared wavelengths, providing crucial measurements of the magnetic field in the corona. During its Operations Commissioning Phase, DKIST has already conducted a significant number of shared-risk observations for community researchers. The complex data obtained from five instruments are calibrated by the DKIST Data Center located in Boulder and distributed to the science community. We’ll present examples of science results, discuss lessons learned and touch on ongoing instrument developments.
13094-36
18 June 2024 • 14:30 - 15:00 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
SUNRISE III is the third flight of the international stratospheric balloon project Sunrise. The SUNRISE III carries a 1-meter aperture Gregorian telescope and provides a unique platform to perform seeing-free observations at UV-Visible-IR wavelengths. It is designed in the framework of NASA's long-duration balloon program to be launched at ESRANGE, Sweden, and to fly to Canada at float altitudes of 35 – 37 km. For the third flight, the post-focal instrumentation was extensively upgraded to enhance spectro-polarimetric capability; SUSI for 309 – 417 nm, TuMag for 525 nm and 517 nm, and SCIP for 765 – 855 nm. The gondola was also renewed to achieve stable pointing to a target on the solar surface. The team led by NAOJ provided SCIP through international collaboration with the Spanish and German teams. SUNRISE III was launched in July 2022 but was terminated because of a hardware problem. The telescope and instruments were successfully recovered and will be flown again in June 2024.
13094-37
18 June 2024 • 15:00 - 15:20 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The Large Millimeter Telescope (LMT) Alfonso Serrano is a bi-national (Mexico and USA) telescope facility constructed on the summit of Sierra Negra, at an altitude of 4600m, in the Mexican state of Puebla. The LMT is a 50-m diameter single-dish radio-telescope designed, constructed and optimized to conduct scientific observations using heterodyne and continuum receivers, as well as VLBI observations, at frequencies between ~70 and 350 GHz.
The LMT has an active surface control-system to correct gravitational and thermal deformations of the primary reflector to enable both night-time and daytime observations. We describe the current status and technical performance of the LMT, the instrumentation development program, and an on-going series of engineering and technical upgrades that will increase the optical efficiency and sensitivity of the telescope which will improve the overall scientific productivity and operational efficiency of the LMT.
13094-38
18 June 2024 • 15:20 - 15:40 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The SDSS-V Local Volume Mapper (LVM) survey employs an array of four, 16-cm telescopes feeding 3 fiber spectrographs at Las Campanas Observatory, with the goal of mapping the entire Galactic plane with 37” spatial resolution and R~4000 spectral resolution. The demands of the survey led to some unique challenges and unconventional design and architecture choices: each telescope uses a two-mirror siderostat in alt-alt configuration feeding optomechanical components, including the fiber feed, on a fixed breadboard. After roughly four years of design, development, construction, testing, and commissioning, the LVM telescopes entered regular survey operations in late 2023. This paper presents an overview of the entire project, from input scientific requirements to the actual performance achieved on-sky.
Break
Coffee Break 15:40 - 16:10
Session 8:
Commissioning & Ops II
18 June 2024 • 16:10 - 17:10 Japan Standard Time | Room G403/404, North - 4F
Session Chair:
Anamparambu N. Ramaprakash, Inter-Univ. Ctr. for Astronomy and Astrophysics (India)
13094-39
18 June 2024 • 16:10 - 16:30 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The MeerKAT+ (MK+) project will extend the current MeerKAT array at the South African Radio Astronomy Observatory (SARAO) site in the Karoo region of South Africa.
The South African MeerKAT telescope is a SARAO precursor to the Square Kilometre Array mid-frequency instrument (SKA-MID). The MK+ project is a partnership between SARAO, the Max Planck Society (MPG, MPIfR), and the Istituto Nazionale di Astrofisica (INAF), and is an important milestone towards the SKA-MID array. We will provide details and updates on the MK+ project.
13094-40
18 June 2024 • 16:30 - 16:50 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The SPECULOOS (Search for habitable Planets EClipsing ULtra-cOOl Stars) project aims to detect temperate terrestrial planets transiting nearby ultracool dwarfs (late M-dwarf stars and brown dwarfs). SPECULOOS is a project led by the University of Liege and carried out in partnership with the University of Cambridge, the University of Birmingham, the Massachusetts Institute of Technology, the University of Bern, and the University of Zurich. It is based on a network of robotic telescopes distributed on two main observatories, SPECULOOS-South in Chile (4 telescopes) and SPECULOOS-North in Tenerife (1 telescope, soon 2), complemented by the SAINT-Ex telescopes (1 telescope in Mexico).
We will present the current status of our facilities after 5 years of operations. Additionally we will discuss our latest development, particularly the upgrade of our weather monitoring system and the recently developed module in our pipeline to detect and asses the impact of the new threat to ground-base observations, the low earth orbit (LEO) satellites. We conclude our work by discussing present challenges in the observatory operations and future developments planned for our facilities.
13094-95
On demand | Presented live 18 June 2024
Show Abstract +
The Super Pressure Balloon-borne Imaging Telescope (SuperBIT) is a diffraction limited 0.5m optical-to-near-UV telescope launched from New Zealand on NASA’s Super Pressure Balloon (SPB) on April 16, 2023 and flew for 45 nights. There were several communication links used during SuperBIT’s flight to communicate with the telescope from the ground, including Starlink, the Tracking and Data Relay Satellite System (TDRSS), Pilot, and Iridium. While Starlink bandwidth was suitable for TCP-based communications and downlinking, the other links were only capable of supporting UDP-based communications. We designed a file transfer algorithm that downlinked files while detecting missing packets in our downlink and requested them automatically, saving limited bandwidth. We also developed a similar mechanism to upload files as 200-byte commands to SuperBIT. In addition to the downlink and uplink programs, we also created an “autopilot” program to automate observations based on the location, time, and a prioritized list of targets. In this paper, we discuss the communication and observation challenges that were faced and strategies we used to overcome these challenges while operating SuperBIT.
Wednesday Plenary
19 June 2024 • 08:30 - 10:00 Japan Standard Time | National Convention Hall, 1F
View Full Details: spie.org/AS/wednesday-plenary
13173-504
Euclid mission: first year of operations
(Plenary Presentation)
19 June 2024 • 08:30 - 09:15 Japan Standard Time | National Convention Hall, 1F
Show Abstract +
After launch on 1 July 2023, the Euclid space telescope of the European Space Agency (ESA) has begun its 6-year mission designed to understand the origin of the Universe's accelerating expansion, which is commonly associated with Dark Energy. By observing billions of galaxies, Euclid will create a 3-dimensional map of the Universe covering 10 billion years of cosmic history. It contains the hierarchical assembly of (dark) matter in galaxies, clusters and superclusters telling us about the nature of gravity and giving us a detailed measurement of the accelerated expansion of the Universe in time. The stringent image quality and sky survey requirements impose extreme performances of the telescope, instruments, and spacecraft. After a mission summary, I will describe the in-orbit spacecraft and instrument performances. A notable challenge is the processing of the large volume of data. The scientific prospects of Euclid are illustrated with the first images and early science results.
13173-505
The ultraviolet explorer: new views of the UV universe
(Plenary Presentation)
19 June 2024 • 09:15 - 10:00 Japan Standard Time | National Convention Hall, 1F
Show Abstract +
The Ultraviolet Explorer (UVEX) mission, scheduled for launch in 2030, advances three scientific pillars: exploring the low-mass, low-metallicity galaxy frontier; providing new views of the dynamic universe, and leaving a broad legacy of modern, deep synoptic surveys adding to the panchromatic richness of 21st century astrophysics. The UVEX instrument consists of a single module with simultaneous FUV and NUV imaging over a wide (10 sq. deg) FOV and sensitive R>1000 spectroscopy over a broad band from 1150 - 2650 Angstroms. In this talk I will describe the UVEX scientific program and provide an overview of the instrument and mission.
Break
Coffee Break 10:00 - 10:20
Session 9:
ELTs
19 June 2024 • 10:20 - 12:10 Japan Standard Time | Room G403/404, North - 4F
Session Chairs:
Breann N. Sitarski, NASA Goddard Space Flight Ctr. (United States), Jason Spyromilio, European Southern Observatory (Germany)
13094-43
ESO’s ELT halfway through construction
(Invited Paper)
19 June 2024 • 10:20 - 10:50 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The construction of the ESO’s Extremely Large Telescope (ELT) passed it 50% completion milestone in 2023. There has been good progress on all fronts over the past two years. The construction site at Armazones (Chile) went from a flat landscape dominated by rocks and lean concrete to a mountain top housing finished structural concrete foundations and an 80m-high dome steel structure. In Europe, the manufacturing of the telescope structure is half complete; Tens of M1 segments have been polished to excellent optical quality; the M2 mirror is quickly approaching its final figuring accuracy; the M4 adaptive mirror has received all its six Zerodur® thin shells and is progressing to full laboratory integration; the M5 has reached a critical step with the brazing of the six CVD-coated SiC petals; the two large Pre-focal Stations are close to start their final testing; the four instruments are all in final design phase with some having started procurement and more.
This paper summarizes the current status of the ESO’s ELT Construction.
13094-44
19 June 2024 • 10:50 - 11:20 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The Thirty Meter Telescope (TMT) is an extremely large optical-infrared telescope with diffraction-limited performance that will shape astronomy research for decades from its northern hemisphere vantage point. The TMT International Observatory (TIO) is a public-private-international partnership that unites the scientific, instrumental and industrial communities of Japan, Canada, India and the USA for this endeavor. TIO is part of the US Extremely Large Telescope Program (US-ELTP) that received the top ranking for the ground-based program in the National Academies’ decadal survey report Astro2020. This paper will describe latest progress in TMT’s design and development in all partner countries, the recent NSF Preliminary Design Review, and the many challenges and opportunities of managing a truly global collaboration. The paper will also discuss in depth our completely new approach since 2021 on community engagement in Hawai’i, genuine listening and learning from the native Hawaiian community including hundreds of people who protested against the Project, and our collaborative efforts with the community to build long-term trust and relationships.
13094-45
19 June 2024 • 11:20 - 11:50 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The Giant Magellan Telescope (GMT) is one of three planned ground-based optical/IR Extremely Large Telescopes (ELTs). Our schedule responds to evolving programmatic factors, and we are engaged in a process to obtain US federal support for part of the construction and operations scope. Of the seven 8.4 m diameter mirror segments comprising the primary mirror, three have been completed and four others have been cast and are in fabrication. The telescope mount has started fabrication. The first off-axis adaptive secondary mirror system is being tested. Two adaptive optics and phasing testbeds are being used for risk reduction with results validating the GMT phasing strategy. Science instruments are in various stages from design through early fabrication. Hard rock excavation of the foundations for the enclosure and telescope pier is complete, and the final design of the enclosure is complete. Residence buildings and other facilities and infrastructure needed to support construction at the Las Campanas site in Chile are complete and in operation.
13094-173
19 June 2024 • 11:50 - 12:10 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The United States Extremely Large Telescope Program (US-ELTP) is a joint initiative of the organizations building the Giant Magellan Telescope (GMT) and Thirty Meter Telescope (TMT) and the NSF’s National Optical and Infrared Astronomy Lab, NOIRLab. The US-ELTP will provide the US astronomical community with open access to observing and archival science with the GMT and TMT via a user services platform supporting the lifecycle of scientific inquiry. In this contribution, we summarize the status of the development and design of the program’s components, highlighting key advances and remaining technical challenges, and describing the next steps in bringing this initiative to fruition.
Session 10:
Astronomy Community Relationships
19 June 2024 • 12:10 - 12:30 Japan Standard Time | Room G403/404, North - 4F
Session Chairs:
Breann N. Sitarski, NASA Goddard Space Flight Ctr. (United States), Jason Spyromilio, European Southern Observatory (Germany)
13094-47
19 June 2024 • 12:10 - 12:30 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
Astronomy is at a turning point in its history and in its relations with the Indigenous peoples who are the generational stewards of land where several of our main observatories are located. The controversy regarding the further development of astronomy facilities on Maunakea is probably the most significant and publicized conflict about the use of such land in the name of science. Thousands have stood in resistance, elders were arrested, and the community is divided. Astronomy’s access to one of its most emblematic sites is at risk. This situation challenges our professional practice, the projects we build on Indigenous lands, and our relationships with the people who live within these lands and with society in general. This paper attempts to share the perspective of the authors on the historical events, including the very recent past, through the lens of our understanding and opinions; to provide transparency, with humility, into our process of introspection and transformation; and to share our hopes and ambitions as leaders from Maunakea Observatories for the future of astronomy in Hawaiʻi, as advocated by the Astro2020 report.
Break
Lunch/Exhibition Break 12:30 - 13:30
Session 11:
Gravitational Wave Observatories
19 June 2024 • 13:30 - 15:00 Japan Standard Time | Room G403/404, North - 4F
Session Chairs:
Tomonori Usuda, National Astronomical Observatory of Japan (United States), Sandrine J. Thomas, Vera C. Rubin Observatory (United States)
13094-48
The LIGO gravitational-wave detector
(Invited Paper)
19 June 2024 • 13:30 - 14:00 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The LIGO gravitational-wave detectors are currently in the middle of the forth observing run, and are routinely detecting multiple gravitational-wave signals from the coalescence of compact objects such as black holes and neutron stars. In this talk I will discuss the technologies that enabled LIGO to reach its unprecedented sensitivity, and the prospects for future improvements.
13094-49
19 June 2024 • 14:00 - 14:30 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
KAGRA gravitational wave telescope in Japan started the 4th international gravitational wave observation(O4) with Advanced-LIGO and Advanced Virgo in May 2023, after repairs, upgrades, and commissioning for 3 years from May 2020. Under the LIGO-Virgo-KAGRA O4 scenario, KAGRA restarted its commissioning from July 2023 to upgrade and improve its sensitivity and to rejoin O4 around Spring 2024. We will present the processes of the improvements and commissioning in KAGRA for O4 and the one-month observation status of KAGRA from 24th May to 21st July 2023.
13094-50
Advanced Virgo+ status and future perspectives
(Invited Paper)
19 June 2024 • 14:30 - 15:00 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The Virgo detector has undergone to a series of improvements since the end of
the O3 observing run in view of O4, as the implementation of an additional recycling cavity at the output of the
interferometer – the Signal Recycling cavity (SRC) – to broaden the sensitivity band.
Some criticality have emerged mainly due to the presence in Virgo of marginally stable recycling cavities with
respect to the stable recycling cavities present in the LIGO detectors, which increases the difficulty in controlling
the interferometer in presence of defects as those introduced by the high power on the mirrors. This resulted
in a delayed joining the O4 run due to a longer than expected commissioning phase. At present the detector is
running with a lower laser power (and a lower sensitivity w.r.t. the project design).
A new stop of about 2 yr is planned between O4 and O5 starting in 2027, to implement new upgrades (phase
II) such as stable recycling cavities, requiring heavy infrastructural works. For the post-O5 phase, a new
collaborative effort has born under the name of Virgo_nEXT to exploit the R&D between O5 and 3rd generation detectors.
Session 12:
ELT Enabling Technologies I
19 June 2024 • 15:00 - 15:40 Japan Standard Time | Room G403/404, North - 4F
Session Chairs:
Tomonori Usuda, National Astronomical Observatory of Japan (United States), Sandrine J. Thomas, Vera C. Rubin Observatory (United States)
13094-51
19 June 2024 • 15:00 - 15:20 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The primary mirror of ESO’s Extremely Large Telescope contains 798 hexagonal segments, which are equipped with position actuators (PACT) for segment piston-tip-tilt actuation and edge sensors (ES) to measure the relative segment displacements. PACT and ES are used for M1 figure control, i.e. for maintaining the reference shape of the primary mirror.
Due to the sheer number of used sensors (4524), ES failures cannot be excluded. In order to minimize the influence of such failures on observations, an automated approach for ES failure handling has been developed.
The figure loop position actuators are hybrid actuators, combining brushless DC motors for a large range of motion with Piezo actuators for high accuracy and fast settling. Motions larger than the Piezo range (~ 10 µm) are restricted to a maximum velocity of 100 µm/sec. Since the figure loop is controlled in modal space such a rate limit introduces non-linearities in this large Multi-Input Multi-Output (MIMO) system resulting in cross-coupling of modes and undesirable transient behavior. A custom management scheme for MIMO systems with actuator non-linearities has been developed and successfully tested.
13094-52
19 June 2024 • 15:20 - 15:40 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
GMTO has developed a full-scale prototype of the cell that can house an 8.4 meter borosilicate mirror. This test cell is populated with all the active support control hardware and a mass simulator that simulates the mirror weight and the moment of inertia. GMTO has implemented the control software with all the core features needed to operate the active support system. A series of tests have been carried out to verify the functions, performance, and safety of the active support control system. The tests were carried out at several different orientations of the cell to demonstrate that the active support system will work with the changing zenith angle and location of the mirror on the mount. This paper describes the results of important safety and dynamic response tests of the active support system.
Break
Coffee Break 15:40 - 16:00
Session 13:
ELT Enabling Technologies II
19 June 2024 • 16:00 - 18:20 Japan Standard Time | Room G403/404, North - 4F
Session Chairs:
Jason Spyromilio, European Southern Observatory (Germany), Anamparambu N. Ramaprakash, Inter-Univ. Ctr. for Astronomy and Astrophysics (India)
13094-53
19 June 2024 • 16:00 - 16:20 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
Ohara was selected to be the supplier of segment blanks for the primary mirror on an extremely large telescope project, notably the Thirty Meter Telescope (TMT). Ohara has been producing and supplying near zero expansion mirror blanks for this project and more than 350 pieces of 1.5 m diameter blanks of CLEARCERAM®-Z HS, of the total quantity required of 574 blanks,were completed.
In this paper we will report the measurement data and evaluation results on the 1.5 m diameter CLEARCERAM®-Z HS blanks targeting the TMT Specifications for M1 Primary Mirror Segment Banks, which includes data on the CTE, CTE uniformity, residual stressand internal quality.
13094-54
19 June 2024 • 16:20 - 16:40 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
ZERODUR® production for the Extremely Large Telescope mirror substrates concludes in 2024. The ELT M1 substrate blank contract is by far the largest serial production ever undertaken for an astronomical telescope, as well as for SCHOTT ZERODUR® manufacturing. The production results demonstrate the maturity and reproducibility of the production process in terms of material properties and dimensional processing capabilities. The installed ZERODUR® manufacturing capacities enabled a continuous ELT M1 blank production on high quality level in parallel to an extraordinary increase in ZERODUR® demand of the IC Lithography equipment industry. This paper reflects the SCHOTT contribution to the ELT. It reviews the excellent data on the coefficient of thermal expansion and the dimensional characteristics achieved for the complete set of 949 M1 segment blanks, vastly better than specified.
13094-55
19 June 2024 • 16:40 - 17:00 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The Extremely Large Telescope (ELT) hosts two Prefocal Stations, one on each of its Nasmyth Platforms A and B. Both units will alternately distribute the light collected by the telescope’s giant optical system into the science instruments and other test equipment, deliver the focal surface images and pupil images of three natural guide stars for acquisition, guiding and wavefront sensing purposes and provide optical sensing to support phasing of the ELT primary mirrors, diagnostics, and maintenance of the optics. The system also hosts the Phasing and Diagnostic Station (supplied by ESO).
The status of each of the subsystems differs. With the PFS Main System fully assembled, the Factory Assembly and Testing (FA&T) campaign is coming to a conclusion. The compliance with the requirements include functional and performance tests on all mechanisms, off-normal mode tests, control system tests, thermal tests, vibration tests and the creation of a calibration pointing map.
We also briefly report on the status of the items hosted in the PFS: imaging and wavefront sensing cameras, metrology equipment, and the Phasing and Diagnostic station.
13094-56
19 June 2024 • 17:00 - 17:20 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
This paper describes in detail the innovative methodologies developed for verification of the most critical performances of the Secondary and Tertiary Mirror Cells (M2 and M3) and the Fifth Mirror Cell (M5) of the European Extremely Large Telescope (ELT). Particularly, the SFE verification for the M2M3 Cells, and the tip-tilt capability verification for the M5 Cell are addressed. It also presents the obtained test results with the corresponding discussion.
13094-57
19 June 2024 • 17:20 - 17:40 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The Giant Magellan Telescope will be a 25 meter optical telescope located in Chile.
The main axes are supported by a hydrostatic bearing system (HBS) which provides an uniform load distribution, an almost stick slip free motion and a kinematic mount.
Deep analyses as FEA, dynamic analyses and hydraulic investigations have been performed to design the system and verify the static and dynamic behaviour of the overall telescope under different scenarios and disturbances as there are: Wind loads, geometrical deviations and seismic events.
The manuscript provides an overview about the main analyses and the design with some special features of the bearing system as the pad grouping with tilting and levelling capability, the extensive oil return & coverage system and the demanding section joints of the bearing tracks.
13094-58
19 June 2024 • 17:40 - 18:00 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The GMT telescope is a high precision large optical device. The telescope will be installed at Las Campanas in Chile, one of the highest seismicity areas worldwide. To protect the high value optical system and instrumentation, a sophisticated seismic isolation system (SIS) has been devised. The SIS will have a double function, needing to provide a high stiffness during the observation while allowing the telescope to move freely during an earthquake filtering the seismic ground accelerations transmitted to the telescope, mirrors, and instruments. To achieve these two opposite functionalities a combined system has been developed comprising: single friction pendulums, viscous dampers, shear pin fuses, a recentering system and a health and safety monitoring system. The system has been validated through Opensees Finite Element (FE) models considering the system multiple non-linearities as well as construction tolerances and accidental torsional effects.
13094-59
19 June 2024 • 18:00 - 18:20 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
In October 2023, The TMT International Observatory (TIO) contracted AMOS to develop the Secondary Mirror Support System and Positioner (M2SSP). The M2SSP was indeed identified as a critical sub-system for which early design was necessary to secure the overall TMT project development plan.
The M2SSP is composed of a semi-active mirror support assembly (M2CA) and a positioner (M2POS) that consists in a hexapod with tracking capabilities.
In this paper is presented the design of the M2SSP elaborated by AMOS to comply with the demanding performances imposed by the operational cases and the environment of TMT. The verification plan is also presented as it is keystone of the work to conduct critical development to the success.
Acknowledgement: This material is based upon work supported by the National Science Foundation under Cooperative Agreement No. 2331108
Thursday Plenary
20 June 2024 • 08:30 - 10:00 Japan Standard Time | National Convention Hall, 1F
View Full Details: spie.org/AS/thursday-plenary
13173-506
Navigating the radio astronomy renaissance: challenges and opportunities for a sustainable future
(Plenary Presentation)
20 June 2024 • 08:30 - 09:15 Japan Standard Time | National Convention Hall, 1F
Show Abstract +
The next decade heralds a renaissance in radio astronomy, with a formidable complement of global Observatories, from LOFAR2.0, to the SKA becoming powerful discovery engines at these lowest frequencies. While they commit to lowering data access barriers, managing the deluge of data poses challenges, as the new constraint on viable astronomy must move from hours on sky to data product cost in energy, compute and carbon and data footprint. I will explore with you the challenges and opportunities in creating a new frontier of sustainable, ethical, affordable astronomy.
13173-507
The x-ray imaging and spectroscopy mission (XRISM): development and expected science
(Plenary Presentation)
20 June 2024 • 09:15 - 10:00 Japan Standard Time | National Convention Hall, 1F
Show Abstract +
The X-Ray Imaging and Spectroscopy Mission (XRISM) project was initiated in 2018 as the recovery mission resuming the high-resolution X-ray spectroscopy with imaging once realized but unexpectedly terminated by a mishap of ASTRO-H/Hitomi. XRISM carries a pixelized X-ray micro-calorimeter array and an X-ray CCD on the focal planes of two sets of X-ray mirror assemblies. The spacecraft was successfully launched from JAXA Tanegashima Space Center on September 7, 2023, and is now conducting performance verification observation followed by guest observations starting in August 2024. In this paper, we present the history of development and recent results.
Break
Coffee Break 10:00 - 10:20
Session 14:
Future Observatories I
20 June 2024 • 10:20 - 12:20 Japan Standard Time | Room G403/404, North - 4F
Session Chairs:
Heather K. Marshall, National Solar Observatory (United States), Trupti Ranka, GMTO Corp. (United States)
13094-63
Updates to the Maunakea Spectroscopic Explorer: thousands of fibers, infinite possibilities
(Invited Paper)
20 June 2024 • 10:20 - 10:50 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
MSE is a massively multiplexed spectroscopic survey facility that will replace the Canada-France-Hawaii-Telescope in the coming decade. This 11.5-m plus telescope, with its 1.5-2.0 square degree field-of-view, will observe 18,000 astronomical targets in every pointing from 360 nm through H-band at low/moderate resolution (R=3,000/7,000) and high (R=30,000). MSE will contribute to nearly every field of astrophysics across all spatial scales, from individual stars to the largest scale structures in the Universe, including (i) the ultimate Gaia follow-up facility for understanding the chemistry and dynamics of the Milky Way, including the outer disk and faint stellar halo (ii) galaxy formation and evolution at cosmic noon, (iii) derivation of the mass of the neutrino and insights into inflationary physics through a cosmological redshift survey that probes a large volume of the Universe. The instrument suite, dedicated to large-scale surveys, will enable MSE to collect massive data, equivalent to a full SDSS Legacy Survey every several weeks. We present an update to MSE along with the plan to develop a Pathfinder instrument at CFHT to fast-track the development of the MSE technology.
13094-60
20 June 2024 • 10:50 - 11:20 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The ground-based Stage-4 Cosmic Microwave Background Experiment (CMB-S4) will map the cosmic microwave background (CMB) with unprecedented sensitivity to answer fundamental questions regarding the origin and evolution of the universe. The project is proposed to be jointly pursued by the U.S. Department of Energy, the National Science Foundation, and international partners. CMB-S4 will deploy the largest arrays of superconducting microwave detectors ever built. The main elements of the CMB-S4 construction project and key technologies required to build the highly optimized survey telescopes are described. The paper introduces the CMB-S4 project organization and a possible project schedule, which maps out mass-producing large quantities of superconducting detector wafers, superconducting readout electronics, and testing of final focus module assemblies.
13094-61
WST - Widefield Spectroscopic Telescope: motivation, science drivers and top level requirements for a new dedicated facility
(Invited Paper)
20 June 2024 • 11:20 - 11:50 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
WST – Widefield Spectroscopic Telescope: Many strategic plans for the future of astronomy have highlighted the demand for deeper widefield spectroscopic surveys for a broad range of key science cases in the areas of Galactic, extra-galactic, time domain and cosmological science. WST will provide simultaneous Multi-object and panoramic Integral Field spectroscopy, initially at visible wavelengths. In each observation the WST Facility aims to provide spectroscopy of >20,000 objects over more than 2.5 square degrees and a central MUSE like integral field of 3*3 arcminutes. We summarise the recent Science White Paper that describes the science drivers, the resultant top-level requirements. We also briefly present the current concept design and the current plans for adoption and implementation.
13094-221
DAG telescope first light commissioning status
(Invited Paper)
20 June 2024 • 11:50 - 12:20 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
DAG, the 4 meter VIS/NIR telescope and the observatory, reached foreseen first light status at last: the enclosure acceptance is completed; to finalize the opto-mechanical alignment and pointing/tracking, the telescope mirrors have been exposed to heavens in absence of instrumentation. On the optical train; the two instruments that make the telescope distinctive, namely KORAY (the optical derotator) and flexible concept TROIA ( ExAO) system’s are characterized at the laboratory, and are anxiously waiting to be installed at their blessed location of mission – the diffraction limited Nasmyth platform along with the PLACID stellar coronagraph and DIRAC (NIR camera). We felt that PLACID, which is not yet lead star got jealous; so with the funding provided by the RACE-GO (ERC Project), within just after 60 days of it’s first mission, it will undergo for a technical makeover to a K-Band instrument. We now have a dilemma, the vacant seeing Nasmyth platform – the land lord- is still waiting for a cutting-edge tenant. Thus, the paper not only presents the telescope and it's instrumentation, but also reserves a dedicated section for possible co-operations/collaborations to take place on the
Break
Lunch/Exhibition Break 12:20 - 13:20
Session 15:
Future Observatories II
20 June 2024 • 13:20 - 15:20 Japan Standard Time | Room G403/404, North - 4F
Session Chairs:
Brialyn Onodera, National Solar Observatory (United States), Bernhard Lopez, Cherenkov Telescope Array Observatory gGmbH (Germany)
13094-64
20 June 2024 • 13:20 - 13:40 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The concept design of an extremely large spectroscopic survey telescope is presented in this paper. The main optical system of this telescope is a four-mirror anastigmatic system delivering good image quality and very compact structure. It provides a 16m aperture primary or even larger, a field of view (FOV) about 5 square degree, and a f-ratio around 4. The main Nasmyth focus is for massively-multiplexed spectroscopic survey with lens-prism strips atmospheric dispersion corrector, which delivers polychromatic encircled energy EE80 in diameter within 0.6 arcsecond across the full field of view at Zenith angle up to 60⁰. Another fold mirror can be moved in before the ADC to feed the light to refine observation instruments or for wide FOV infrared observations. A coude system optimized for ground layer adaptive optics with FOV 6arcmin can be designed to give a gravity invariant focus for very high resolution spectrograph or giant IFUs. Some experimental results related to the manufacture of the lens-prism strips ADC and the supporting structure will be given in this paper too.
13094-65
20 June 2024 • 13:40 - 14:00 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
Solaris is a scientific and technological project aimed at the development of a smart Solar monitoring system at high radio frequencies based on innovative single-dish imaging techniques, recently approved as a permanent observatory in Antarctica. Solaris can perform continuous Solar imaging observations nearly 20h/day during Antarctic summer with optimal sky opacity. In perspective our system could be implemented also in the northern hemisphere to offer Solar monitoring for the whole year.
13094-66
20 June 2024 • 14:00 - 14:20 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The Large Fiber Array Spectroscopic Telescope (LFAST) will provide a large, scalable collecting area, equivalent to or greater than other ELTs under construction, at a much reduced cost. LFAST will carry out scientific investigations that require spectroscopy with high-signal-to-noise or of faint objects. LFAST is an array telescope, combining light from hundreds of 0.76m diameter prime focus telescopes into a single fiber-fed spectrograph. Twenty telescopes will be mounted on a common alt-az mount, and we are currently constructing the first prototype twenty-unit system. In this talk we will present status and updates from the first 2.5 years of the LFAST project, and describe plans for large arrays, including a 200-unit system in the next few years and a 2,640 unit system in the future.
13094-67
20 June 2024 • 14:20 - 14:40 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The next-generation Event Horizon Telescope (ngEHT) will be a transformative upgrade to the Event Horizon Telescope (EHT), capable of making real-time and time-lapse movies of supermassive black holes on event horizon scales. These movies will resolve complex structure and dynamics in the immediate vicinity of the event horizon, bringing into focus not just the persistent strong-field gravity features predicted by General Relativity (GR), but details of active accretion and relativistic jet-launching that drive large scale structure in the Universe. This effort builds upon recent results by the EHT: the first image of M87’s supermassive black hole and its magnetic field structure, as well as resolved images of Sgr A*, the central black hole at the heart of the Milky Way.
13094-68
20 June 2024 • 14:40 - 15:00 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The Atacama Large Aperture Submm Telescope (AtLAST) is a concept for a novel 50-meter class single-dish telescope operating at sub-millimeter and millimeter wavelengths (30-950 GHz). The telescope will provide an unprecedented wide field of view (FoV) of 1 – 2deg diameter with a large receiver cabin housing six major instruments in Nasmyth and Cassegrain positions. The high observing frequencies, combined with the scanning operation movements with up to 3deg/s, placing high demands on accuracy and stability of the optical and structural components. The planned site location is in the Chilean Atacama Desert at approximately 5100 meters above sea level, near Llano de Chajnantor.
The paper gives an overview on the optical, structural, and mechanical design concepts. It explains the flow down from key science requirements to technical design decisions as well as showing design analogies from other existing large radio and optical telescopes. Results from structural and performance analyses are presented.
13094-69
20 June 2024 • 15:00 - 15:20 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
A wide-field optical IR spectroscopic survey telescope is designed to deliver spectra of several millions of astronomical sources. The baseline design of the telescope is a 6.2m segmented primary mirror with 19 hexagonal segments, 84 edge sensors, & 57 soft actuators. The telescope is designed to provide a 2.5deg FOV achieved through a system of wide field corrector lenses with a design residual <0.2". Also, it delivers an f/3.6 beam suitable for directly feeding optical fibres. A mechanical concept of the telescope is designed with a truss-based mirror cell to support the segmented primary mirror and keep deformation to a minimum. As the primary mirror is segmented, the deformation due to different disturbances like wind, vibration and thermal effects must be corrected to a nanometer accuracy to make it act like a monolithic primary mirror. A simulation tool, codeSMT, is built using the state-space model to incorporate dynamic wind disturbance from the IAO Hanle site and vibration effects. A detailed parameter sensitivity & error multiplier analysis is performed numerically using this tool. This paper presents an Optical, Mechanical and Active Control system design of telescope.
Break
Coffee Break 15:20 - 15:50
Session 16:
Robotic Telescopes
20 June 2024 • 15:50 - 17:10 Japan Standard Time | Room G403/404, North - 4F
Session Chairs:
Tomonori Usuda, National Astronomical Observatory of Japan (United States), Jason Spyromilio, European Southern Observatory (Germany)
13094-70
20 June 2024 • 15:50 - 16:10 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The Argus Array will be the first large optical telescope capable of exploring the entire sky simultaneously. Consisting of 900 small-aperture telescopes with ultra-low-noise detectors multiplexed into a 55 GPix array, Argus will have the equivalent collecting area of a 5m telescope but will explore the sky in a very different way from conventional survey telescopes. Each Argus exposure covers 8,000 square degrees with a sampling of 1.4"/pixel; this enormous field of view allows the Array to achieve deep imaging by observing every part of the sky at cadences as fast as one second – for 6-10 hours each night. Realtime transient detection systems will process the incoming images at TB/sec speeds on a high-speed GPU cluster. Over five years, the Array will build a publicly-available, two-color, million-epoch movie of the northern sky, giving the astronomical community the unprecedented ability to follow the evolution of every deep time-variable source across the sky simultaneously. We will detail the current status of the Argus project, including construction plans and first results from the on-sky Argus Pathfinder hardware and software prototype system.
13094-71
20 June 2024 • 16:10 - 16:30 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The Gravitational-wave Optical Transient Observer (GOTO) is a project dedicated to identifying optical counter-
parts to gravitational-wave detections using a network of dedicated, wide-field telescopes. After almost a decade
of design, construction, and commissioning work, the GOTO network is now fully operational with two antipodal
sites: La Palma in the Canary Islands and Siding Spring in Australia. Both sites host two independent robotic
mounts, each with a field-of-view of 44 square degrees formed by an array of eight 40 cm telescopes, resulting
in an instantaneous 88 square degree field-of-view per site. All four telescopes operate as a single integrated
network, with the ultimate aim of surveying the entire sky every 2–3 days and allowing near-24-hour response
to transient events within a minute of their detection. In the modern era of transient astronomy, automated
telescopes like GOTO form a vital link between multi-messenger discovery facilities and in-depth follow-up by
larger telescopes. GOTO is already producing a wide range of scientific results, assisted by an efficient discovery
pipeline and a successful citizen science project: Kilonova Seekers.
13094-74
20 June 2024 • 16:30 - 16:50 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The rapidly increasing population of Earth-orbiting debris is forcing novel ideas and new partnerships within the US Space Force (USSF). Here the US Space Force presents a concept for a mobile, off-grid, robotic observatory for rapid deployment and observational support. This 1-meter aperture, 3-degree FOV telescope employs state-of-the-art commercial instrumentation in support of both satellite orbit cataloging and closely-spaced object characterization at atmospheric seeing limits, i.e. sub-1" pixels. Its relatively large etendue, high throughput, and up to 50 deg/s slews provides for high survey speeds, be it for lost space debris or astronomical transients. We will detail the design and simulated performance of this Deployable, Attritable Optical (DAO) system. Furthermore, each system will employ USSF developed observatory control software called SensorKit, completely open-source, enabling robotic operation and, if desired for SDA purposes, communication with the Unified Data Library. Scheduling, tasking, data processing and dissemination and more are a part of the US Space Force MACHINA program, presented separately in these proceedings.
13094-75
20 June 2024 • 16:50 - 17:10 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
Time domain astronomy is revolutionizing our understanding of the universe. One of the biggest issues with the flood of temporal data is following up on the plethora of discoveries. There just is not enough telescope time available to observe the new objects in detail, especially spectroscopically. Building a new 3 meter class telescope is very expensive, but a telescope that size would be ideal to observe a large fraction of the objects. We propose to create a custom 3 meter telescope, using 1 meter mirrors mounted on the same telescope frame. Each mirror would feed a dedicated fiber optic, and the whole telescope would be designed to be easily replicable and maintainable, as well as have high optical throughput and be fully automated. Once the first "multiple telescope telescope" has been commissioned, multiple copies would be built and stationed around the world, creating a new network of spectroscopic telescopes that can continually monitor the sky. Versions of this technology could be used to build 6 or 8 meter telescopes for far less than a single monolithic mirror.
Session 17:
Metrology & Alignment
21 June 2024 • 08:30 - 10:10 Japan Standard Time | Room G403/404, North - 4F
Session Chair:
Bruce C. Bigelow, GMTO Corp. (United States)
13094-197
21 June 2024 • 08:30 - 08:50 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The Hobby-Eberly Telescope (HET) is an innovative 10m-class telescope that operates with a fixed altitude segmented spherical primary mirror (M1) while a tracker, located at the top of the telescope, moves the prime-focus spherical aberration corrector (SAC) and instrument package in order to track the sidereal and non-sidereal motions of celestial objects. In 2016, we completed the wide-field upgrade of the telescope, which includes the Wide-Field Corrector (WFC), the tracker, the prime focus instrument package, and all electro-mechanical hardware and telescope control software. Post the upgrade, we have been monitoring the image performance of the telescope through the in-situ metrology. These metrology streams highlight weak spots of the telescope facility in imaging performance and provide quantitative guidance to specific facility repair and/or upgrades to further improve the HET’s overall performance. This paper summarizes our long-range (7yrs) datasets, specific analysis techniques used, and current outcomes of this effort in the context of specific facility improvement and upgrade plans.
13094-77
21 June 2024 • 08:50 - 09:10 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
COALA is an instrument aimed to measure the relative alignment and piston of any three adjacent segments of the primary mirror of the GTC during day, without using stellar light. A quasi-puntual white light source placed at the telescope focus generates a collimated beam that is analysed by COALA, which is attached to the telescope dome. Combined motion of COALA and telescope mounts permit to scan the full aperture of the telescope without the need of an intruder mechanical system in front of the primary mirror.
13094-78
21 June 2024 • 09:10 - 09:30 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The primary mirror (M1) of the Hobby Eberly Telescope (HET) consists of 91 mirror segments in a regular hexagon shape. The M1’s center of curvature can be accessed from the top of a 90ft-tall tower just outside the HET dome. The current alignment metrology system in this tower, called the Center of Curvature Alignment System (CCAS), keeps the 91 segments into a single smooth 11-meter diameter surface. This critical alignment function is at risk due to the obsolescence and deficiencies of the aging system. There are many reasons to upgrade the CCAS. The upgrade includes a suite of advanced metrology instruments to provide improved alignment precision and metrology. In particular, the upgrade features a new dispersed fringe sensing (DFS) technique capable of measuring the piston error of all 240 segment edges across the HET’s 11m primary mirror in a single-shot exposure based on wavelength multiplexing, arrayed diffractive components, and spatial filters. This paper summarizes the electro-opto-mechanical design of the system and other design features to be implemented in the upgrade.
13094-79
21 June 2024 • 09:30 - 09:50 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The Sardinia Radio Telescope performance upgrade is completed and now it has the capabilities to scan the universe up to a maximum radio frequency of 116 GHz, corresponding to a wavelength of 2.6 mm. Nevertheless, observing at the highest frequencies for which SRT has been designed, requires a tighter control of the pointing and main reflector surface accuracy than before. This is possible through the mitigation of effects produced by environmental loads that were previously negligible. Therefore, a new metrology system, called SMS, has been implemented to face the new challenges. This paper aims to provide a description of strategies conceived to use the SMS system instrumentation, in order to achieve the planned functional objectives.
13094-80
21 June 2024 • 09:50 - 10:10 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The Giant Magellan Telescope is a 25.4-m visible/infrared telescope being built as one of the next-generation Extremely Large Telescopes. The size of the GMT and its doubly segmented design creates a unique set of challenges for telescope alignment, including initial alignment during the assembly, integration, verification and commissioning phase and operational alignment between and during the telescope exposures. GMT is developing a Telescope Metrology System (TMS) that uses networks of laser trackers and absolute and differential distance-measuring interferometers for improved alignment efficiency and phasing of the mirror segments. The TMS has successfully passed its Preliminary Design Review and entered the Final Design phase. The current design of the TMS is presented and the expected performance is discussed.
Break
Coffee Break 10:10 - 10:40
Session 18:
Alignment & WFS
21 June 2024 • 10:40 - 11:40 Japan Standard Time | Room G403/404, North - 4F
Session Chairs:
Jason Spyromilio, European Southern Observatory (Germany), Tomonori Usuda, National Astronomical Observatory of Japan (United States)
13094-81
21 June 2024 • 10:40 - 11:00 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The advantage of large optical telescopes from the ground for high-contrast direct imaging relies on achieving exquisite control of the incident optical wavefront. Since the exoplanet problem almost always has a bright star within a small field of view there are usually ample photons for measuring the atmospheric and telescope-distorted wavefront. A 5-year ERC-funded Laboratory for Innovation In Opto-Mechanics (LIOM) has just begun at the Instituto de Astrofísica de Canarias (IAC). Measuring the wavefront using Machine Learning techniques in combination with a photonic lantern offers the possibility of fully common-mode wavefront sensing for combining the Fizeau telescope sub-apertures to minimize scattered light and to perform accurate wavefront nulling ("dark spot" or "vortex" nulling) in the image plane. Here we describe our progress in implementing this approach through numerical and laboratory simulation.
13094-82
21 June 2024 • 11:00 - 11:20 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The Alignment and Phasing System (APS) of the Thirty Meter Telescope (TMT) will use Shack-Hartmann-type measurements to determine the relative alignment and shapes of the segments of the primary mirror (M1). These measurements are required to be made with minimal errors in order for M1 to act as a diffraction-limited mirror. As TMT commissioning time will be limited, full performance must also be achieved as quickly as possible. From the earliest stages of the design, the TMT APS team has therefore emphasized work that ensures that APS will work as well and as close to out of the box as possible and reduces the associated risks. We describe efforts on algorithm and software development, analytical studies and simulations, on-sky and laboratory experiments, and prototyping. We explain how they have affected the design of the APS hardware and software and why we are confident that this critical subsystem of TMT will achieve its goals.
13094-83
21 June 2024 • 11:20 - 11:40 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
For a segmented mirror telescope, the desired resolution can only be achieved when all its mirror segments are precisely co-aligned, co-focused, and co-phased. Co-phasing is one of the most stringent tasks in handling the segmented mirror telescope, and so far, many different phasing techniques have been developed. The OTF-based phasing technique samples light from the center of the segments and uses the magnitude transfer function (MTF) to derive the phase/piston error. Through realistic simulations, we have attempted to explore this OTF-based phasing of segmented mirrors. The effect of different kinds of noises, filter-detector spectral response, sampling aperture, presence of optical losses, signal strength, and atmospheric conditions on the accuracy of the piston measurement has been studied in detail. OTF is also found to be sensitive to segment tip/tilt errors, and hence we have tried to study the cross-talk between piston and tip/tilt errors. In addition to simulation, we also attempted to conduct laboratory experiment so that simulation results can be validated. In this paper, we present the results of our extensive simulation as well as experimentation.
Break
Lunch Break 11:40 - 13:00
Session 19:
Opto-Mechanical Designs I
21 June 2024 • 13:00 - 15:00 Japan Standard Time | Room G403/404, North - 4F
Session Chair:
Mario Tapia, European Southern Observatory (Chile)
13094-84
21 June 2024 • 13:00 - 13:20 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The Atacama Large Aperture Submillimeter Telescope (AtLAST) aims to be the premier next generation large diameter (50-meter) single dish observatory capable of observations across the millimeter/sub-millimeter spectrum, from 30 to 950 GHz. The large primary mirror diameter, the 2-degree field of view and its large 4.7-meter focal surface give AtLAST a high throughput (aperture size times field of view) and grasp (throughput times spectral reach), with the ability to illuminate O(10 Million) detectors. The optical design concept for AtLAST consists of a numerically optimized two-mirror Ritchey-Chrétien system with an additional flat folding mirror, which enables a quick selection among its planned six instrument positions. We present the optical design concept and discuss the expected optical performance of AtLAST. We then present design concepts that can be implemented in the receiver and instrument optics to correct for astigmatism and mitigate the high degree of curvature of the focal surface in order to recover significant fractions of the geometric field of view at sub-millimeter wavelengths.
13094-85
21 June 2024 • 13:20 - 13:40 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The Vera C. Rubin Observatory, advancing towards its goal of a 10-year Legacy Survey of Space and Time (LSST), recently installed the M1M3 cell and steel mirror surrogate onto the Simonyi Survey Telescope's Mount Assembly. This primary/tertiary mirror, crucial for image quality, was tested under conditions simulating rapid observation field changes, essential for the observatory’s ambitious sky mapping schedule. These tests, extending from 1-100% of the designed telescope slew performance, assessed the M1M3 system’s stability, hardpoint behaviors, and the efficacy of the dynamic compensation forces provided by the support system. Preliminary results suggest the system meets operational requirements, ensuring safety and effectiveness at full speed and precise control of mirror figure.
13094-86
CANCELED: Evolution of the Dragonfly Telephoto Array: from galaxies to the cosmic web
21 June 2024 • 13:40 - 14:00 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
We describe our plan to continuously evolve the Dragonfly Telephoto Array into the world's most powerful spectral line mapping machine. Dragonfly has recently been upgraded to have the sensitivity needed to map out the distribution of diffuse gas in the circumgalactic medium of local galaxies. Our next upgrade will focus on increasing the size of the array to allow imaging of the dark matter Cosmic Web.
13094-87
21 June 2024 • 14:00 - 14:20 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
Dome-C in the Antarctic Plateau is a privileged site for Astronomy, with one of the lowest concentrations of water vapor in the world, providing a pristine atmospheric window for IR observations. Together with the long winter nights, this allows for extended continuous observational campaigns. At the Concordia Station, ASTEP has taken advantage of the weather and long nights to observe long-period transiting exoplanets for over a decade. With the Cryoscope Pathfinder we now plan to take advantage of the dark IR window between 2.35 and 2.55𝜇m.
The unique design of Cryoscope Pathfinder is optimized for a very wide field of view and very thermal background. It is a cryogenic 0.26 m telescope designed for observations in K-dark with a field of view of 16 deg^2. This is the first step for a much more ambitious project, the full scale 1-meter class Cryoscope telescope, with a field of view of 50 deg^2. The initial science drivers are the study of exoplanets and of the infrared transient sky, where it will play a major role in the localization of gravitational wave sources. Furthermore, many other science topics will be enabled by Cryoscope and through synergies with other surveys.
13094-88
Conceptual design of the infrared Integral Field Spectropolarimeter for the European Solar Telescope
21 June 2024 • 14:20 - 14:40 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The European Solar Telescope (EST) will be Europe's most ambitious ground-based infrastructure in solar physics. It will have a primary mirror with a diameter of 4.2 m, which will make it the largest in Europe, and of identical aperture as the largest solar telescope available worldwide, namely DKIST installed in Hawaii. EST will have two main characteristics devoted to maximising the scientific return. First, the telescope's optical path will be polarisation-free using pairs of mirrors that compensate for instrumental polarisation. Second, the telescope will be designed together with a complete instrument suite with imaging and spectrograph instruments. EST will also bring many new technologies, such as a multi-conjugate adaptive optics system and integral field spectro-polarimeters. This contribution presents the conceptual design of the infrared (1 to 1.8 microns) integral field spectropolarimeter. The instrument will have an integral field unit composed of a mirror-based image slicer as input to a Czerny-Turner spectrograph. It will have a polarimeter to record the polarisation state of light on a dual-beam configuration to ensure high-precision spectro-polarimetry.
13094-89
21 June 2024 • 14:40 - 15:00 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The M2 secondary mirror of the Vera C. Rubin Observatory will be the first 3.4 m active mirror to see the sky in 2024. Here, we report on the integration, testing and verification of the M2 surrogate with the M2 cell, initially in the integration hall and subsequently on the Telescope Mount Assembly, including the M2 light baffle installation inside the dome. We report on the complex installation procedure and the three test campaigns that encompass the characterization of a wide spectrum of M2 cell functionalities, such as the actuator's behavior in terms of maximum stroke and force limits, inner and outer control loop mode behavior, active and un-powered support of the M2, rigid body motion repeatability, motion limits, and lookup tables optimization.
Break
Coffee Break 15:00 - 15:30
Session 20:
Opto-Mechanical Designs II
21 June 2024 • 15:30 - 17:10 Japan Standard Time | Room G403/404, North - 4F
Session Chairs:
Tomonori Usuda, National Astronomical Observatory of Japan (United States), Jason Spyromilio, European Southern Observatory (Germany)
13094-90
21 June 2024 • 15:30 - 15:50 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The Gregor Infrared Spectrograph (GRIS) is installed at the Gregor telescope at Observatorio del Teide, Spain. The instrument started observations in 2012 and underwent several upgrades in the following years. Currently, it is experiencing the most significant upgrade so far, which includes, among other things, adding two optical channels to perform simultaneous multi-wavelength observations. One of the elements we need to modify to optimise the performance of the instrument on all the new spectral channels is the Polarisation Module Unit (PMU). In this contribution, we want to present our theoretical analysis, laboratory experiments, and first-light results related to the new version of the PMU. This new version and many of the improved capabilities of the instrument will be offered to the community gradually during 2024.
13094-91
21 June 2024 • 15:50 - 16:10 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
CMB-S4, the next-generation CMB observatory will deploy hundreds of thousands of detectors to enable mapping the millimeter-wavelength sky with unprecedented speed. The large-aperture telescopes for CMB-S4 consist of six-meter diameter crossed Dragone designs to be deployed in Chile and an innovative five-meter diameter three-mirror anastigmat to be deployed in the South Pole. The two-mirror crossed Dragone requires instrument corrections as demonstrated earlier in these proceedings. We discuss biconic lens corrections for the CMB-S4 crossed Dragone telescope camera optics and we give an overview of the camera optics for the three mirror anastigmat as the optical designs of the cameras for these telescopes are prepared for manufacture.
13094-92
21 June 2024 • 16:10 - 16:30 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The preliminary optical design of EST has been optimized to maximize throughput, balance the instrumental polarization and to reduce the image rotation due to the change in orientation during operation. The optical system consists of a 4.2 m active primary mirror and an adaptive secondary mirror. Followed by four deformable mirrors conjugated to different layers of the atmosphere and a dioptric system, housed in a vacuum vessel, to transfer the secondary focal plane to the science focus. Finally, the light is delivered to the Scientific Instrumentation by a dedicated distribution system. This contribution outlines the optical design of EST, details its subassemblies and discusses its final performance.
13094-93
21 June 2024 • 16:30 - 16:50 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The New Robotic Telescope (NRT) is an autonomous telescope that can operate multiple instruments at the Cassegrain focal station and the straight-through port. The optical beam is directed to the ports by a fold mirror subsystem in the focal station assembly. The fold mirror is elliptical in shape, manufactured by Istituto Nazionale di Astrofisica (INAF), and polished down to RMS surface deformation of λ/20. An optomechanical analysis is performed to simulate the effect of gravity over the mirror surface deformation and the results have been compared to the interferometry plots to optimize the Ion Beam Figuring (IBF) process to polish the mirror aperture. The design and manufacturing of the mirror assembly, including the gluing process, will be summarised as part of this presentation.
13094-94
21 June 2024 • 16:50 - 17:10 Japan Standard Time | Room G403/404, North - 4F
Show Abstract +
The ELT M1 Local Coherencer is a non-contact metrology system aimed to simultaneously measure the relative pistons on the six sides of a target M1 segment with respect to neighbouring ones (reference segments) with an accuracy below 300nm in a range of ±250μm while it is supported by the M1 Segment Manipulator hanging from the M1 Segment Crane. For this purpose, the Local Coherencer is equipped with six Sensing Modules integrating,
- a patented partially coherent light interferometer,
- an absolute tip-tilt sensor and a fine local alignment system to orient the system normal to the reference segment, and
- a coarse alignment detection system composed of a distance sensor and a border visualisation camera.
The Preliminary Design described in a precedent paper has been further optimized to provide a better performance of the interferometer. Additonally, as a part of the Final Design effort, an Early Unit of a Sensing Module has been built and tested to validate the expected performance, check the correct operation of its three measurement systems as well as the local alignment system and test the latency of the measurements. This paper covers the Design and results discussion.
Session PS1:
Posters - Commissioning
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
View
Tuesday Poster Session schedule and event details
Each day includes a unique set of posters. Poster groupings are listed below by topic.
13094-96
On demand | Presented live 18 June 2024
Show Abstract +
The Dragonfly Spectra Line Mapper (DSLM) is a mosaic telescope optimized for ultra low surface brightness imaging of visible wavelength line emission. The design is based on the Dragonfly Telephoto Array, with the addition of ultra narrow bandpass filters in front of each lens. The telescope was constructed in four phases from March 2022 to November 2023. Since the original 10-lens phase, various hardware upgrades were introduced. Here we describe the construction and commissioning of the complete 120-lens array, as well as the implementation of various hardware upgrades. Additionally we present updated characterization of the cameras and filter transmission for the full array. Finally, we reflect on the construction process and remark on the feasibility of a larger 1000-lens array.
13094-97
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
The Wendelstein First Ring (WFR) is an automated multi-focal station that is designed to efficiently and precisely distribute telescope light at one of the Nasmyth ports to various scientific instruments. It will be installed at the 2.1m telescope of the Wendelstein Observatory which is currently equipped with two imaging cameras, the Wendelstein Wide field imager (WWFI), and a three-channel camera (3KK) in addition to a high-resolution comb-calibrated spectrograph (FOCES). The WFR will enable the observer to change within 90s between the latter two instruments or provide calibration light to the devices. Furthermore, it offers the possibility for alignment optimization of the telescope via a wavefront sensor. We will report on the verification of the different light paths and the repeatability of switching between them. Finally, we will describe the commissioning process after mounting the WFR to the telescope.
13094-98
On demand | Presented live 18 June 2024
Show Abstract +
The Vera C. Rubin Observatory is nearing completion, and we are embarking on a campaign to optimize the image quality for its upcoming 10-year optical survey. Here we present the tools and methods that we are implementing to disentangle and quantify the different sources of image degradation, as well as plans to correct and mitigate these sources where possible.
Session PS2:
Posters - Commissioning & Operations
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
View
Tuesday Poster Session schedule and event details
Each day includes a unique set of posters. Poster groupings are listed below by topic.
13094-163
On demand | Presented live 18 June 2024
Show Abstract +
The Lowell Discovery Telescope (LDT) is a 4.3-m telescope in Arizona constructed for astronomical observations in the optical and near IR. This report looks at the mirror support load cells and steps taken to individually evaluate and re-calibrate them.
13094-164
On demand | Presented live 18 June 2024
Show Abstract +
The Dragonfly Spectral Line Mapper is an innovative all-refracting telescope designed to carry out ultra-low surface brightness wide-field mapping of visible wavelength line emission. Equipped with ultranarrowband (0.8 nm bandwidth) filters mounted in Dragonfly Filter-Tilter instrumentation, the Dragonfly Spectral Line Mapper maps Hα, [NII]λ6583, and [OIII]λ5007 line emission produced by structures with sizes ranging from ~1 to 1000 kpc in the local Universe. These spatial scales encompass that of the exceedingly diffuse and faintly radiating circumgalactic medium, which is singularly difficult to detect with conventional mirror-based telescope instrumentation. Extremely careful control of systematics is required to directly image these large scale structures, necessitating high fidelity sky background subtraction, wavelength calibration, and specialized flat-fielding methods. In this paper, we discuss the on-sky performance of the Dragonfly Spectral Line Mapper with these methods in place.
13094-166
On demand | Presented live 18 June 2024
Show Abstract +
The signal induced by a temperate, terrestrial planet orbiting a Sun-like star is an order of magnitude smaller than the host stars' intrinsic variability. Understanding stellar activity is, therefore, a fundamental obstacle in confirming the smallest exoplanets. We present the Lowell Observatory Solar Telescope (LOST), a solar feed for the EXtreme PREcision Spectrometer (EXPRES) at the 4.3-m Lowell Discovery Telescope (LDT). EXPRES is one of the newest high-resolution spectrographs that accurately measure extreme radial velocity. With LOST/EXPRES, we observe disk-integrated sunlight autonomously throughout the day. In clear conditions, we achieve a 137,500 optical spectrum of the Sun with a signal-to-noise of 500 in 150s. Data is reduced using the standard EXPRES pipeline with minimal modification to ensure the data are comparable to the observations of other stars with the LDT. During the first three years of operation, we find a daily RMS of 71 cm/s. Additionally, having two EPRV spectrometers located in Arizona gives us an unprecedented opportunity to benchmark the performance of these planet-finders. We find a RMS of just 55 cm/s when comparing EXPRES and NEID.
13094-167
On demand | Presented live 18 June 2024
Show Abstract +
The Super-pressure Balloon-borne Imaging Telescope (SuperBIT) is a diffraction limited 0.5m optical-to-near-UV telescope that was designed to study dark matter via cluster weak lensing. SuperBIT launched from Wanaka, NZ via NASA’s super pressure balloon technology in 2023 and remained in the stratosphere for 39 days. SuperBIT obtained multi-band images for 30 targets; data analysis to produce shear measurements for each target is ongoing. We provide an overview of the instrument commissioning process and performance. The first two days of the flight were used for payload characterization and telescope alignment after which the flight was dedicated to science observations. There are three subsystems for which we provide performance data: pointing, power, and thermal. SuperBIT consists of three nested frames which enable telescope pointing stability of 0.34” as well as a fine guidance sensor which produces a focal plane image stability of 0.055” over 300s exposures. The power system reached full charge every day and did not ever drop below 30%. All components remained within their temperature limits and actively controlled components remained at their set point within ~0.1K.
Session PS3:
Posters - ELT Enabling Technologies
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
View
Tuesday Poster Session schedule and event details
Each day includes a unique set of posters. Poster groupings are listed below by topic.
13094-46
On demand | Presented live 18 June 2024
Show Abstract +
The US Extremely Large Telescope Program (US-ELTP) is a joint initiative of the organizations building the Giant Magellan Telescope (GMT) and the Thirty Meter Telescope (TMT), and the NSF's National Optical-Infrared Astronomy Research Laboratory (NOIRLab). The US-ELTP will enable all U.S. astronomers to carry out transformational research that fully leverages the diverse capabilities of both the GMT and TMT, as well as the two-hemisphere system. In this paper, we present an overview of the program's scientific goals, the high-level roles and responsibilities of the US-ELTP partners, and the operating modalities of the joint program, including science and engineering operations for science investigators and archival research support.
13094-169
On demand | Presented live 18 June 2024
Show Abstract +
The Primary Mirror Control System (M1CS) of the Thirty Meter Telescope (TMT) incorporates 1476 precision electromechanical soft actuators that are used to perform closed-loop control of the 492 primary mirror segments in piston, tip and tilt. This paper describes the evolution of the M1CS actuator design from the early concept through several prototype rounds towards a design suitable for production at-scale. It offers insight into how TMT has and continues to meet the unique challenges and opportunities associated with manufacturing across an international partnership, in particular the need for high quality technical oversight and documentation at all stages of the process from prototype development, modeling, drawing production and subsequent assembly, test and verification. Key design decisions, refined through prototyping and testing to ensure optimum performance, reliability and serviceability are highlighted. Insight is given into the activities undertaken by TMT partners and vendors in India, especially as part of the vendor selection and vendor qualification that was undertaken as part of TMT’s Production Qualification Phase (PQP) process.
13094-170
On demand | Presented live 18 June 2024
Show Abstract +
The GMT telescope is equipped with three large utility wraps for the main axes. From the very beginning of the design phase, these were considered critical sources of vibration. Since no information was available on the vibration behavior of the utility wraps at low speeds during tracking, a great deal of effort was put into the planning and execution of a test campaign using a 1:1 scale test bench. One of the special features was a novel structure identification technique using unbalanced motors as a cost-effective yet reliable alternative to the commonly used shaker actuators.
13094-171
On demand | Presented live 18 June 2024
Show Abstract +
The ELT M1 Segment Concentrator cabinet grew from the need to optimize the power consumption of the control electronics for all M1 Segment Assemblies. These, are located below the segment assemblies the main challenges were the demanding heat dissipation requirements while keeping the electronics within reasonable working temperatures. To minimize the heat dissipation bespoke heat exchangers were design and tested. A PLC based Power Distribution and Control Unit was design to control and monitor a 24VDC power supply that distributes power to all subsystems pertaining to 7 segments subunits hosted by the M1 Segment Concentrator. It provides feedback to the M1LCS at all times, but more importantly during maintenance operations, and in particular during the segment exchange operation. 132 M1 Segment Concentrators distributed across the M1 Cell host the control electronics of the 798 M1 Segment Subunits that shape the ELT primary mirror. This paper presents the challenges during the design phase of the segment concentrator and how they were solved in order to finalize its design, their production and currently their integration during the ELT AIV phase.
13094-174
On demand | Presented live 18 June 2024
Show Abstract +
The Giant Magellan Telescope (GMT) primary mirror subsystem (M1S) consists of seven 8.4 m diameter borosilicate
primary mirrors that must be maintained at the ambient nighttime air temperature as it changes throughout the observing
night to prevent seeing effects at the mirror surface. Additionally, thermal gradients internal to the mirrors must be
minimized to prevent figure errors caused by distortions of the mirror due to the non-zero thermal expansion coefficient
of the glass. To address these requirements, the GMT M1S team is fabricating a prototype thermal control system design that consists of a sub-critical refrigeration system utilizing high pressure (~30 to ~60 bar) CO2 (R744) refrigerant. This paper describes the design and status of the M1 Subsystem Thermal Control (M1STC).
Session PS4:
Posters - Enclosures
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
View
Tuesday Poster Session schedule and event details
Each day includes a unique set of posters. Poster groupings are listed below by topic.
13094-175
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
The dome of the Grantecan was delivered after its construction partially inoperative, due to problems with the contractor. The shutters of the dome did not work. The maintenance team managed to get it operational, with opening limitations. The telescope was inaugurated with this restriction in 2009. In 2015, a refurbishment was carried out, changing some of the major hardware and adding a new control strategy for the aperture. With these improvements it was possible to use the full functionality of the dome shutters, with full opening and emergency degraded closing, without relying on all the motors. Another problem was a defective assembly and design of the rotation bogies. It was decided to upgrade and correct them in 2023 to avoid wear of the bogies and the rail and to reduce vibrations towards the telescope. This could not be carried out in the previous months due to the ash caused by the Cumbre Vieja volcano. The bogie correction was then carried out progressively without affecting the scientific operations. The poster presents these advances that have strengthened the GRANTECAN dome without negatively impacting science operations.
13094-176
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
A novel high performance clamshell system is presented. The design is scalable to medium sized 4m class telescopes, and allows the installation of complex system for ventilation, wind screening, telescope maintenance, and thermal control. The rsults of the firtst products realized at EIE are also presented.
13094-177
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
The Near-Earth Object Survey TELescope (also knowm as "Flyeye") represents a key element of S2P. Its role consists of providing a real-time monitoring system from the ground of potential impactors, generating an early-warning signal with a maximum delay of three days from detection to alert generation. Due to the peculiarities of the "Flyeye" telescope, the hosting astronomical observatory shall comply with specific and tight requirements. Advanced, modular, highly reliable dome systems and auxiliary building solutions for observatories dedicated to space debris and NEO detection are presented.
13094-178
On demand | Presented live 18 June 2024
Show Abstract +
The DAG (Dogu Anatolu Gözlemevi) observatory is the largest observatory in Turkey. This presentation refers to the DAG Rotating Enclosure. At the beginning of November 2023, EIE carried out all acceptance tests with the end customer and delivered the rotating enclosure to ATASAM. This paper will provide the results of the final erection and reports the procedures and results of the Acceptance Tests performed by EIE for the DAG Rotating Enclosure
13094-179
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
The Magdalena Ridge Observatory (MRO) is an astronomical observatory focused on both research and education, located on the Magdalena Ridge in New Mexico, the result of a scientific collaboration between the New Mexico Institute of Mining and Technology (New Mexico Tech – NMT) and the Cavendish Astrophysics Group at the University of Cambridge.
MRO will used to support Astronomy, Optical and near-infrared radiation, Space situational awareness, Education and Research. The MRO array will simulate a single-telescope parabola by operating at wavelengths between 0.6 and 2.5 micron, with a baseline of a diameter between 7.8m and 340m.
Session PS5:
Posters - Future Observatories
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
View
Tuesday Poster Session schedule and event details
Each day includes a unique set of posters. Poster groupings are listed below by topic.
13094-180
On demand | Presented live 18 June 2024
Show Abstract +
We present the Near-Ultraviolet eXplorer (NUX), which will consist out of 4 small (36 cm diameter) ground-based telescopes that are optimized for the shortest wavelengths that are detectable from Earth (i.e., the near-UV [NUV] wavelength range of 300-350 nm). Each telescope will have a field-of-view of ~17 square degrees sampled at ~2.5”/pixel, and will reach a NUV magnitude of 20 in 2.5 minutes exposures. The goal of NUX is to improve our understanding of the physical processes that power fast (days) to very fast (hours) hot transients, such as shock-breakout and shock-cooling emission of supernovae and the electromagnetic counterparts of gravitational wave events. Each telescope will be an off-the-shelf 14” Celestron RASA telescope, retrofitted with NUV optics. We have already demonstrated that the normal Schmidt corrector of this telescope can be replaced by a custom made one consisting of NUV transparent glass. Currently, a prototype NUX telescope is being fully assembled to demonstrate the technical and scientific feasibility of the NUX concept. Site tests will be held (in 2025/2026) at La Silla, Chile, to determine the NUV characteristics of the atmosphere at this site.
13094-182
On demand | Presented live 18 June 2024
Show Abstract +
WST – Wide-field Spectroscopic Telescope: we summarise the outcome of initial opto-mechanical design activities on a 12m class Telescope that would provide a large (>3 square degree) field of view and enable simultaneous Multi-object (> 20,000 objects) and Integral Field spectroscopy (inner 3x3 arc minutes field of view), initially at visible wavelengths. We describe the outline conceptual design and the associated key features of the Telescope and Dome.
13094-183
On demand | Presented live 18 June 2024
Show Abstract +
Here we describe Taurus, a balloon-borne CMB experiment optimized to map the CMB E-mode polarization and foregrounds at the largest angular scales (ℓ<30) and improve measurements of the optical depth to reionization (τ). The instrument will map 60% of the sky enabled by a mid-latitude launch location and NASA’s super-pressure balloon platform. Taurus will employ more than 10,000 100mK detectors distributed across two low-frequency (150, 220 GHz) and one high-frequency (280, 350 GHz) dichroic receivers. The liquid helium cryostat housing the detectors and optics is supported by a lightweight gondola. The payload is designed to meet the challenges in mass, power, and thermal control posed by the super-pressure platform.
13094-184
On demand | Presented live 18 June 2024
Show Abstract +
MezzoCielo is a project of a monocentric optical system with a spherical glass envelope built up by meniscus arranged onto a Platonic or Fullerene-like structure filled with industrial liquid characterized by high transparency and low refractive index. Optical design of the cameras, implying the choice between large multiplexing and moderate individual field of view vs. a limited amount of cameras aiming to correct a much larger individual field of view is presented, along with the current status of the engineering aspects of its design. A case study for such a telescope as a patrol of GW telescope in order to allow almost real-time pinpointing of the associated multimessengers potential sources is given, showing its capability to explore a unique science.
13094-185
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
The Square Kilometre Array MPI Prototype Antenna (SKA-MPI) and the current under construction MeerKAT+ project, extending the 64-dish MeerKAT array, are located at the South African Radio Astronomy Observatory (SARAO) site in the Karoo region of South Africa. As a radio quiet zone, the site provides an excellent location for detecting radio signals from weak astronomical sources. Therefore, the requirements on self-induced RFI/EMI emissions are extremely strict. The emission levels of the antennas with their electronic control and drive systems need to be low enough to not interfere with or corrupt the received astronomical signal, which is a clear challenge to the design and on the test equipment for verification.
We will present the development and verification of an innovative RFI quiet telescope control and drive system design that forms the basis of the SKA-MPI and MeerKAT+ antennas.
Show Abstract +
This paper describes a telescope concept that has an aperture area equivalent to 88 m in diameter by 16 telescopes with an aperture of 22 m placed closely within a 250 m range. The primary mirror uses an off-axis spherical mirror fixed to the ground, and a subsequent correction unit corrects most of the aberrations of the primary mirror which is placed on a high cliff to track diurnal motion for 20 minutes. Multiple correction units can be operated simultaneously in the north-south direction. Wide-field cameras and spectrographs are equipped for every telescope to perform high-speed deep surveys and high S/N spectroscopic observations. All telescopes have laser-guided star adaptive optics, deaylines, and coude paths which allows light from all telescopes to be focused in one location in phase to function as one ultimate telescope for observation of exoplanets and galactic objects with high angular resolution and high sensitivity.
13094-187
On demand | Presented live 18 June 2024
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A quad-mirror (QM) telescope ooptical concept has been designed for the Maunakea Spectroscopic Explorer project. The goal to repurpose the existing CFHT site without changing the footprint of the observatory imposes numerous constraints on the telescope including space constraints limiting the size of the telescope and the space available for the large number of spectrographs required, dimensional constraints (limits the size of any monolithic mirrors), mass limits along with other logistical constraints that wouldn't necessarily exist for a facility designed from first principals. The QM concept offers several scientific and versatility advantages over the original prime focus baseline, but it poses some challenges, such as the size of the tertiary mirror. This design serves as input into the effort to understand how best to implement the QM design and to determine if there are any arising hard show stoppers. We present an overview of the optical design with its benefits, areas of compromise to meet currently known constraints, and evaluation of preliminary optical sensitivities and metrology needs.
13094-188
On demand | Presented live 18 June 2024
Show Abstract +
Cryoscope will be a diffraction limited 1.2m telescope with 50 deg2 field of view contributing less thermal background than the dark K band sky at the Concordia Base in Antarctica. Cryoscope Pathfinder is 26cm version which has been built and is soon to be deployed at Dome C to retire technical risks. This paper reviews key design choices that make the substantial increase in field of view and reduction in thermal background possible. We address the technical challenges associated with the new approach and with operation over the > 100 C temperature difference between laboratory and winter at Dome C. The athermal window support and bonding are described. The baffling and thermal models are presented along with strategies for preventing condensation on the large vacuum window which radiates significant heat into the cryogenically cooled telescope. We conclude with a vision for a modular prefabricated tower to raise the telescope above the 25-30 m inversion layer, and an approach to image stabilization, so that diffraction limited imaging can be achieved over the full field of view.
13094-189
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
The search for extrasolar planets is an important tool for expanding our understanding of the Universe and exploring the possibility of life on other planets. Among the several approaches employed for this purpose, the astrometric method offers significant advantages, as it provides an accurate estimate of the mass of the investigated planet, which is not required to be aligned with the line of sight of the observer as for the transit or radial velocity techniques.
This work aims at analysing the pointing manoeuvres required by a future spacecraft carrying an optical instrument such as RAFTER to properly fulfil the objectives of an exoplanet astrometric search mission. RAFTER is an annular field telescope conceived and proposed with the goal of achieving consistent optical response over a wide field of view, which exhibits a compact and scalable design and enforces circular symmetry for each optical element.
A mathematical model describing the dynamics of the system and the evaluation of an appropriate optimal control strategy will be presented. At the end, the selection of proper actuators will also be discussed.
13094-190
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
The Multiplexed Survey Telescope (MUST) is 6.5m class optical telescope to be located in mainland China, at Saishiteng Mountain, Lenghu Town, Qinghai Province. The elevation is approximately 4.350m above sea level. The MUST Rotating Enclosure will provide environmental protection and control to the Telescope during operation and standby conditions as well as providing the infrastructure required for the operation of the Telescope. The Auxiliary Building will house plant, maintenance and storage facilities and the coating facility for the primary and secondary mirrors. A non-corotating dome architecture is chosen in order to improve flexibility during telescope maintenance and material handling. The rotating enclosure dome includes a moving wind screen, ventilation doors and a rear access door for main mirror handling. The contract to design and build the rotating dome and design the lower enclosure and auxiliary building was awarded to EIE GROUP in Mestre-Venezia, Italy in 22/12/22.
Show Abstract +
We present a design for a wide-field spectroscopic telescope with 12m aperture and 3 degree Field-of-View. Three simultaneous modes are offered: (a) Natural seeing MOS over 3° with ~25,000 targets; (b) MOAO over 3° with 84 AO-corrected IFUs each with 4" FoV; (c) GLAO-corrected IFU over 15'. Such a telescope would be uniquely powerful for all-sky followup of imaging surveys, with AOmega exceeding all existing spectroscopic facilities combined. The expected cost of this design is relatively modest, being much closer to $500M than $1000M.
13094-192
CANCELED: The EXoplanet Climate Infrared TElescope (EXCITE)
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
The EXoplanet Climate Infrared TElescope (EXCITE) is a 0.5 meter near-infrared spectrograph that will fly from a high altitude balloon platform. EXCITE is designed to perform phase-resolved spectroscopy -- continuous spectroscopic observations of a planet's entire orbit about its host star -- of transiting hot Jupiter-type exoplanets. With spectral coverage from 0.8 -- 4 um, EXCITE will measure the peak of a target's spectral energy distribution and the spectral signatures of many hydrogen and carbon-containing molecules. Phase curve observations are highly resource intensive, especially for shared-use facilities, and they require exceptional photometric stability that is difficult to achieve, even from space. In this work, we introduce the EXCITE experiment and explain how it will solve both these problems. We discuss its predicted sensitivity and stability, then provide a detailed overview of the as-built instrument, including performance data EXCITE achieved from the ground during its 2023 field campaign in Ft. Sumner, NM. Finally, we detail preparations as for a planned 2024 engineering flight from North America and future long duration science flights from Earth's poles.
Session PS6:
Posters - Metrology & Alignment
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
View
Tuesday Poster Session schedule and event details
Each day includes a unique set of posters. Poster groupings are listed below by topic.
13094-193
On demand | Presented live 18 June 2024
Show Abstract +
Precision in optical alignment is crucial for optimizing image quality in astronomical telescopes, particularly for wide-field survey telescopes such as the Vera C. Rubin Observatory, which will conduct the Legacy Survey of Space and Time (LSST). This paper explores the deployment and efficacy of laser tracker technology, specifically the Leica AT960/930, in maintaining optical alignment of the Simonyi Telescope within tens of microns, marking it as one of the first wide-field telescopes to implement such advanced metrology. Here, we detail the outcomes of employing this technology in its integration, initial setup, and preliminary operations. We present detailed results on the structural flexure of the telescope at varying elevations and the effects of gravitational dynamics on the misalignment of optical components. Our findings demonstrate that the operation of the laser tracker within the Active Optics System (AOS) allows realigning components within stringent tolerances in a single step, achieving near-perfect initial alignment. These capabilities establish a new benchmark for optical alignment in future large astronomical facilities.
13094-194
On demand | Presented live 18 June 2024
Show Abstract +
The key to ensure the accuracy of the closed-loop system is the accurate measurement of the reference fiber position, but the system error of the laser tracker itself, the temperature change and the air flow in the environment have a great influence on the measurement results. A measuring error compensation device based on the relative position of three standard length bars in space is presented. The device is based on three indium steel rods with very small thermal expansion coefficient and accurately verified length. The measuring deviation of rod length and relative position between rod and rod during operation is related to the measuring error of reference fiber. The position error of reference fiber on focal plane can be corrected in real time according to the correlation algorithm. Finally, experiments show that the error of laser tracker in reference fiber position measurement can be effectively reduced by this device.
13094-195
On demand | Presented live 18 June 2024
Show Abstract +
The alignment of optical systems is a crucial aspect to be considered in the design phase of astronomical instruments. As the size of telescopes and the related instruments is increasing, also the needs to have flexible measuring tools is developing in parallel to satisfy the scientific requirements.
The development of the alignment techniques for small instruments is well validated throughout the history of the Optomechanical and astronomical instrumentation, nevertheless those techniques cannot be applied on large ones. This thesis proposes a procedure that allows to evaluate the position of optical elements in large volume very precisely. This enables the achievement of the scientific goals by minimizing the alignment procedure duration the costs.The case study presented here is MORFEO which is a first-light instrument for the European Extremely Large Telescope.
13094-196
On demand | Presented live 18 June 2024
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Presented in this paper is the latest technique developed at the W.M. Keck Observatory for calculating the optimal warping solution for unwarped segments in the telescopes called BAMM!. The new technique is used to improve the warping solution for challenging segments with a reduction in the segment warping forces. This solver has been in operation for the last 3 years.
13094-198
On demand | Presented live 18 June 2024
Show Abstract +
The John A. Galt 26m radio telescope is an important astronomical instrument for the Canadian radio astronomy community. The prime focus telescope is ideal for spectropolarimetric studies of the interstellar medium. Nonetheless, under various gravity loading conditions, the structural deformation in the telescope causes unpolarized radiation into a polarized signal which corrupt the astronomical signal. In addition to that, due to the equatorial mount arrangement, the tripod-shaped feed support structure also changes its position depending on the pointing direction. This variation also affects the reflective surface and the feed position relative to the reflective surface.
A detailed finite element (FE) model of the antenna has been created to characterize the effects and related deformation of the structure. Gravity related surface and support structure deformation was studied. As a part of the FE model verification, a photogrammetry-based antenna metrology was conducted. The surface RMS errors are between 3 - 4 mm when compared with a best-fit paraboloid. In addition to the error characterization, the photogrammetry setup and challenges are also discussed in this article.
13094-199
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
Jiao Tong University Spectroscopic Telescope(JUST) is of great significance to Chinese astronomy. The 4.4-meter primary mirror of JUST will adopt segmented mirror active optics to realize co-phasing in near-infrared bands. Co-phasing errors of segmented primary mirror tiled by hexagonal segments are successfully calculated for JUST. Besides, Co-phasing errors including out-plane errors are simulated lonely and comprehensively, so that a lot of simulation results are successfully received which lay a solid foundation for JUST.
13094-200
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
Inductance-to- Digital Converters (LDC) based differential inductive displacement Sensors with frequency output
Xiaolong Lu , Zongwen Wang ,You Wang ,Guiyun Tian, Dehua Yang and Yong Zhang
1 School of Mechanical Engineering, Sichuan University, Chengdu 610065, China
2 School of Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
3 Nanjing Institute of Astronomical Optics & Technology, Chinese Academy of Sciences, Nanjing 210042, China;
4 CAS Key Laboratory of Astronomical Optics & Technology, Nanjing Institute of Astronomical Optics & Technology, Nanjing 210042,China
Abstract:
An edge displacement sensor is one of the most key technologies for building segmented mirror telescopes. Traditional edge displacement sensors mainly use Analog-to-Digital converter (ADC) interfaces, and its signal conditioning circuit is complex and high power consumption, which is not conductive to the digital transformation and the Internet of Things (IoT) in particular. This article proposes a frequency output sensor based on Inductive-to Digital Converter (LDC) , which is low-cost, high sensitivity, high stability and consists of a differential structure. The time drift and temperature
13094-201
On demand | Presented live 18 June 2024
Show Abstract +
We have developed an ultra-stable eddy current edge displacement sensor with a resolution better than 1nm (RMS) within a range of 250μm. During on-site testing at the Guoshoujing Telescope (the Large Sky Area Multi-Object Fiber Spectroscopic Telescope LAMOST) telescope, the sensor exhibited a temperature drift within ±2nm/℃ after temperature compensation and achieved a drift of less than 25nm over 5 weeks. The test results indicate that, by relying on sensor feedback, the telescope has the potential to achieve high-quality co-focusing over extended periods and significant temperature ranges, thereby enhancing the operational efficiency and observation quality of the telescope.
13094-202
On demand | Presented live 18 June 2024
Show Abstract +
Star cameras were initially developed in the 1960 primarily for defense and satellite navigation. While commonly utilized on satellites, their application to high-altitude balloon flights presents unique challenges when extracting stars from a variable and high scatter background. Atmospheric scattering and mesospheric clouds pose additional hurdles for accurate star field observations and make background subtraction and stray light mitigation critical features of a star camera design used in high altitude balloon experiments. Additionally the presence of highly sensitive radio payloads in scientific high-altitude balloon flights necessitates shielding the star tracker from contaminating the radio background. This work presents the innovative design of a star camera employed in the Payload for Ultrahigh Energy Observations high-altitude balloon experiment (PUEO).
Session PS7:
Posters - Modeling as a Driver of Observatory Design
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
View
Tuesday Poster Session schedule and event details
Each day includes a unique set of posters. Poster groupings are listed below by topic.
13094-203
On demand | Presented live 18 June 2024
Show Abstract +
This paper is focused on tracking control strategies for a ground-based telescope, comparing model-based solutions to more classical alternatives.
To this aim, the state-space representation of the telescope axes is identified by using experimental data and a pre-processor is adopted for the computation of the position trajectories, ensuring that all physical constraints in terms of speed and acceleration are always respected. The case study of the TNG telescope is used in this work.
Within this framework, we synthesize a double-layer control adopting a Kalman filter based Linear-Quadratic-Gaussian-Proportional-Integral (LQGPI) controller which ensures the reference position is accurately tracked.
The virtual simulations carried out via an ad-hoc simulation platform implemented in Matalb&Simulink,
show the effectiveness of the hierarchical control architecture for a representative set of star trajectories, considering several realistic conditions. Then, a comparison analysis with a PI controller is provided to discuss the advantages and benefits of the proposed control solution.
13094-204
CANCELED: Framework for Identifying and Separating Individual Sources for Radio Imaging Data in the SKA Era
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
SKA, the Square Kilometre Array, stands as one of the largest radio telescopes to date, covering a broad frequency range from hundreds of hertz to tens of gigahertz. This wide frequency coverage enables the observation of data across multiple frequency channels, encompassing a wealth of radio information. Such multi-frequency observations are crucial for understanding the diversity and complexity of radio sources. In this study, we augmented a deep neural network with the Convolutional Block Attention Module(CBAM). The integration of this module significantly improved the precision of radio source detection while slightly reducing the recall rate. Subsequently, we performed a two-dimensional fitting for detected radio sources, including both point sources and extended sources, at each frequency. This process yielded crucial parameters for each source. Additionally, we have also achieved preliminary fitting of three-dimensional data. These fittings, along with their parameters, offer a more precise and comprehensive description, providing robust support for radio astronomy research.
13094-205
On demand | Presented live 18 June 2024
Show Abstract +
The Vera C. Rubin Observatory is poised to achieve its highly anticipated first light in early 2025, marking the start of an era of transformative observational capabilities. As the observatory nears its first light, the commissioning of the Active Optics System (AOS) becomes increasingly critical. Comprising an open-loop and a closed-loop component, the AOS delivers real-time corrections for the alignment and mirror surface perturbations, ensuring seeing-limited image quality across the 3.5-degree field of view. In this paper, we present a thorough examination of recent advancements in the AOS at the Rubin Observatory. We begin by detailing the enhancements in the open-loop system, focusing on the improvement of Look-Up Tables (LUTs). Next, we discuss the closed-loop control improvements, particularly our novel approach using double Zernike polynomials and improvements made to eliminate degeneracies. Overall, these initial verifications and improvements not only mark significant progress towards full-system verification, but also refine the capabilities of the AOS, which is key for maintaining long-term operational efficiency and achieving the required image quality.
Session PS8:
Posters - Mounts
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
View
Tuesday Poster Session schedule and event details
Each day includes a unique set of posters. Poster groupings are listed below by topic.
13094-207
On demand | Presented live 18 June 2024
Show Abstract +
National Astronomical Observatory of Japan (NAOJ) has been responsible for the Telescope Structure Subsystem (STR) of the Thirty Meter Telescope (TMT) since 2012 and has engaged Mitsubishi Electric Corporation (MELCO) for preliminary and final design and pre-production work.
There are various subsystems on the telescope such as instruments and moving optics. Power and fluids are required for these subsystems and for the telescope drives. TMT defines the Telescope Utility Services (TUS) as the infrastructure which includes the cabling, piping, and support structures used to organize, route and deliver these utility services, as well as the lighting and fire alarms that are integrated onto the telescope structure etc. The TUS components are varied in type and location, and use a multitude of attachment methods to the telescope structure.
This paper presents the design implementation of the TUS components onto the telescope structure.
13094-208
On demand | Presented live 18 June 2024
Show Abstract +
Under construction in the Karoo desert is the first of 133 radio telescope dishes that will join the existing 64 from MeerKAT to make up the mid-frequency half of the Square Kilometre Array Observatory (SKAO). Erecting the dish is merely the first stage of a long and rigorous process this and the following 132 antennas must undergo before they are able to produce reliable scientific data. The next step is verification and validation (V&V) where mechanical engineers from the South African Radio Astronomy Observatory (SARAO) will work under complex conditions performing V&V activities. As part of these activities data must be read from, and commands sent to, the dish structure controller; a PLC based control system exposed via an OPC-UA server interface. In comes the dish structure qualification software (DiSQ), a collection of tools designed to expose the OPC-UA server in an intuitive, user-friendly manner via a Python API and an engineering GUI to facilitate and expedite the V&V.
Show Abstract +
LFAST (Large Fiber Array Spectroscopic Telescope) is planned to provide a cost-efficient way to provide a large collecting area for spectroscopy by duplicating large numbers of small (0.76m aperture “unit” telescopes, each equipped with a prime focus corrector feeding an optical fiber.
The design of each telescope is driven by the need to minimize costs while achieving adequate performance, through the innovative use of low-cost commercial components and industrial manufacturing processes. Sets of twenty unit telescopes are mounted together on a single, compact tracking ALT-AZ “20x” telescope mounting, using a lightweight steel truss frame and driven by pairs of commercial slew-bearing worm drives.
13094-211
On demand | Presented live 18 June 2024
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Small-ELF (SELF), a 3.5-meter telescope entering manufacturing, is a precursor to the larger ELF (Exo-Life Finder). The design aims to significantly enhance exoplanet imaging while maintaining cost-effectiveness through innovations in motion control, shape control, machine learning, and tensegrity techniques. SELF's manufacturing begins in 2024-2025, detailed in this paper. To mitigate risks, a 0.25-meter prototype, MicroELF, is developed in 2024, employing distributed aperture principles and controllable degrees of freedom based on optical feedback and machine learning. Both SELF and MicroELF address cost and scalability challenges, presenting a new paradigm in large telescope structural design.
13094-212
On demand | Presented live 18 June 2024
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The 4-m Shanghai Jiaotong University Spectroscopic Telescope (JUST) will be sited at the Lenghu Observatory in Qinghai Province, China. The primary mirror of the telescope is a hyperbolic surface with a nominal aperture of 4.4 meters. The primary mirror is composed of 18 hexagonal concave segments, each with a size of about 1.1 meters across the corners and a central thickness of 75 mm. The segmentation of the mirror is an important task that influences the complexity of optical fabrication and the support design of the segment mirrors. In this paper, we present a novel method for segmenting the hyperbolic primary mirror of the 4-m JUST based on the method of rigid body motion of the segments and the principle of maximum likelihood of the shape of the segments. We also take into account the uniform gap of nominal 4 mm between segments and perpendicular flat lateral and back surfaces of the segments. We compare our method with existing methods and show that our method can achieve better results in terms of the likelihood of the edge/chord lengths of the segments. We also discuss the advantages and challenges of our segmentation method for other large optical telescopes
13094-213
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
The 4-m Shanghai Jiaotong University Spectroscopic Telescope (JUST) is a segmented optical telescope to be sited at the Lenghu Observatory in Qinghai Province, China. The tertiary mirror of the telescope is an elliptical zerodur plano mirror of 1485x1025x160 mm3. A lightweighting scheme to is used to remove up to 60% of the mirror mass. A 12-point Whiffle-tree is used for axial support of the mirror and 4 sets of counter-weight for lateral support, with a central positioning mechanism. The reflecting shape of the mirror is down to 8 nm RMS under gravity in any working direction.
13094-214
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
The ASTRI Mini-array is an international project led by INAF to study the gamma-ray universe within a spectral range of 1 to a few hundred TeV. A cluster of nine Cherenkov telescopes in dual-mirror configuration will be implemented at the Observatorio del Teide in Tenerife, Spain. EIE, under INAF's supervision, is responsible for the electromechanical design, manufacturing, installation, and commissioning of the first 3 telescopes of the ASTRI Mini-array. This followed the successful deployment of the ASTRI-Horn prototype in Sicily in 2014. Each telescope has a primary mirror of 4.3m in size, made up of 18 mirror segments (that mimic a monolith structure) that are aligned by a set of 54 actuators, which have a range of 12 mm and an accuracy of 0.05 mm. They can be removed and displaced from one telescope to another, reducing maintenance costs. In this brief update, we present an overview of the structural, mechanical, and mechatronic solutions that have been developed and implemented in the ASTRI telescopes to achieve the project's technical and scientific objectives.
13094-216
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
In the context of the Italian Resilience and Recovery Plan (PNRR), INAF and INFN proposed the "CTA+" Program aimed at extending the scope and strengthen the scientific return of the Southern Cherenkov Telescope Array Observatory (CTAO) site. The main objective of this program is to realize and implement two end-to-end Large-Sized Telescopes (LSTs) at CTAO-S as part of the LST Collaboration. The approved and full-funded program has formally began on January 1st, 2023 and has a duration of 36 months. The baseline design of the mechanical structure will be based on that of the northern LSTs, apart from some possible changes to fulfil the environmental specifications of the southern site and further reduce the construction risks and costs. The mirrors will be produced using a technology invented in Italy by INAF, via a cold replica of glass slabs to make the 2 m diameter mirrors. The camera will be almost identical to those of LST-N. The production of the cameras, mirrors and mechanical structures will be realized through large industrial contracts that will be supervised by the CTA+ management with the full support of the LST Collaboration.
13094-217
On demand | Presented live 18 June 2024
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The 4m New Robotic Telescope (NRT) is an optical facility designed to revolutionize the rapid follow-up and classification of variable and transient objects. The freezing of key system architecture features at the preliminary design review in 2021 has allowed significant progress to be made towards a target of Engineering First Light in 2027. The project critical path is currently driven by the optics and the enclosure. Both of these components are novel in design: the NRT will have an 18-segment primary mirror and a large, fully-opening clamshell enclosure. Particular progress has been made regarding enclosure design, software & control, science & operations software and the focal station and associated science support instrumentation. The Critical Design Review for the M3 (fold mirror) was completed Q4 2022 which enabled manufacturing of the first NRT glassware to begin and prototyping of the complete opto-mechanical, hardware and software subsystem for its control to take place. NRT will join the 2m Liverpool Telescope on La Palma, and as such this existing facility has been exploited to prototype the new science operations user interface and the wavefront sensor.
Session PS9:
Posters - Observatory Construction Updates
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
View
Tuesday Poster Session schedule and event details
Each day includes a unique set of posters. Poster groupings are listed below by topic.
13094-219
On demand | Presented live 18 June 2024
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Lowell Observatory has converted a historic equatorial mount telescope facility into a modern 1m alt-az telescope research facility with preparations for remote operations. The PlaneWave PW1000 Nasmyth mounted commissioning instrument is the Teledyne-PI SOPHIA 4k CCD camera with custom lightweight filter wheel, integral payload support, and optical alignment capability. Design considerations of the vibration optimized support structure, instrumentation, dome renovation, general facility, and initial results are reviewed.
Session PS10:
Posters - Observatory Upgrades & Repairs
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
View
Tuesday Poster Session schedule and event details
Each day includes a unique set of posters. Poster groupings are listed below by topic.
13094-99
On demand | Presented live 18 June 2024
Show Abstract +
The Cherenkov Telescope Array Observatory (CTAO) will include telescopes of three different sizes, the smallest of which are the Small-Sized Telescopes (SSTs). In particular, the SSTs will be installed at the southern site of CTAO, on the Chilean Andes, and will cover the highest energy range of CTAO (up to ~300 TeV). The SSTs are developed by an international consortium of institutes that will provide them as an in-kind contribution to CTAO. The optical design of the SSTs is based on a Schwarzschild-Couder-like dual-mirror polynomial configuration, with a primary aperture of 4.3m diameter. They are equipped with a focal plane camera based on SiPM detectors covering a field of view of ~9°.
13094-100
On demand | Presented live 18 June 2024
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Astronomical observatories are pivotal in unraveling the mysteries of the cosmos. To ensure their operation and longevity, Facility Condition Assessments (FCAs) play a vital role in determining maintenance and funding needs for these unique facilities. By prioritizing maintenance needs, guiding and justifying budget allocation, and documenting compliance, FCAs assist in maintaining safety and operational efficiency, help sustain the scientific mission of these facilities, and help sustain their supporting infrastructure. This paper presents the general concept behind an FCA and a case study highlighting the impact of FCAs on several renowned astronomical facilities. As astronomy continues to expand our understanding of the universe, FCAs emerge as a critical tool in supporting the mission of these scientific institutions, fostering long-term sustainability, and justifying funding requirements to stakeholders.
Show Abstract +
We present an ongoing project involving the transformation of a decommissioned 32-meter communication antenna located in Tulancingo, Hidalgo, Mexico, potentially capable of operating up to K-Band. Originally designed for C-band frequencies, this antenna is now being evaluated for potential use in the K-band after a decade of disuse. Our assessment encompasses various refurbishment steps necessary for antenna operations, including new motors and the installation of modern motion encoders and controllers, facilitating fully remote operation.
13094-102
On demand | Presented live 18 June 2024
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Telescopio Nazionale Galileo (TNG) has successfully deployed its new Telescope Control System (TCS). This paper focuses on the technical details of the upgrade, highlighting key improvements and showcasing the enhanced functionality and reliability of the new TCS. The development and deployment were carefully planned, incorporating 3D simulations and overlapping with other maintenance operations to minimize the impact on observational time. With new advanced features, such as a modular architecture and the use of a graphical programming language, the TCS enables easy on-the-fly testing of control algorithms for future developments.
13094-103
On demand | Presented live 18 June 2024
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For more than ten years, the Gregor Infrared Spectrograph (GRIS) has been the infrared spectropolarimeter on the Gregor telescope since its inauguration in 2012. The instrument mainly performs polarimetric observations of the wavelength regions at 1083 and 1565~nm, which have high scientific potential. There, observers can find spectral lines that provide information on the atmospheric parameters over a vast range of atmospheric layers and with high sensitivity to the magnetic field. Due to the high demand for GRIS and the versatility of the Gregor environment, we decided to upgrade the system once more, allowing it to become one of the instruments with the highest potential in any ground-based solar observatory. This time, the upgrades add two spectral channels for performing multi-wavelength observations in long-slit or IFU mode.
13094-104
On demand | Presented live 18 June 2024
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Achieving smooth and efficient slew movements on telescope mounts is crucial for minimizing structural stress, reaching maximum velocities, and ensuring efficient operation. Traditional slew trajectory generation methods often fall short in optimizing trajectories for time, resulting in unnecessarily long slew times that reduce telescope efficiency and potentially affect observation opportunities.
This paper presents a novel time-optimal jerk-limited trajectory generator algorithm for slew movements and its current implementation at the SOAR telescope as part of the Mount Control Upgrade Project. This algorithm effectively addresses these limitations by simultaneously optimizing for user-defined constraints on position, velocity, acceleration, and jerk while achieving minimum time. The algorithm produces a jerk-constrained trajectory that converges to a constant velocity reference specified by position, velocity, and time (PVT) commands, ensuring smooth and efficient convergence to tracking velocities while minimizing structural stress and settling time.
13094-105
On demand | Presented live 18 June 2024
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The telescope structure of the Stratospheric Observatory for Infrared Astronomy (SOFIA) was subject to vibration excitation due to aircraft motions and airflow. To contribute to the efforts to meet pointing requirements and improve image stability, an active mass damping system for the primary mirror suspension had been designed and implemented during the early years of observatory operation phase. Various reasons had prevented further development for some time, but we were able to reactivate and operate the damping system for a set of select missions before the premature decommissioning of the observatory. We present analyses from gathered engineering data and from astronomical observations regarding the the effectiveness of the system during those missions and offer a projection on how future SOFIA campaigns would have benefited.
13094-106
On demand | Presented live 18 June 2024
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The W.M. Keck Observatory’s (WMKO) Hydrostatic Bearing Systems (HBS) supply the Keck I and Keck II telescopes with filtered, cooled, and pressurized oil. This systems lift the telescopes up on oil allowing them to float on the bearings and rotate with ease. The pressurized oil supplied by these systems is also required to release the brakes, allowing telescope motion. Each telescope has its own independent HBS as well as its own HBS control system. WMKO’s HBS had been running on the original 1980's era relay logic control system. However, in the late summer and early fall of 2023 the HBS control systems for both telescopes were replaced. Replacing and modernizing control systems is nothing out of the ordinary, however both Keck I and Keck II HBS control systems were replaced without any downtime to nighttime operations. In addition to the installation resulting in no loss of observing, there is now a greater capacity for monitoring, troubleshooting and improved energy efficiency as well as remote operations. In this paper, we will describe the equipment and methods used to replace the control system while maintaining nighttime operations and discuss the modernization benefits.
13094-107
On demand | Presented live 18 June 2024
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This paper showcases the successful development of an altazimuthal control system for a radio telescope using industrial PLC platforms. The high-level programming language, structured text, is employed to perform the essential calculations for converting equatorial to altazimuthal coordinates and orchestrating the independent axis movements for time-based tracking. The tracking strategy is based on correcting the movement speed (variable rate) of each independent axis considering an acceleration ramp S to reduce the jerk, thereby achieving a smooth and uniform movement.
13094-108
On demand | Presented live 18 June 2024
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This paper shows some of the Maintenance strategies employed on the ESO's Very Large Telescope's (VLT) encoder systems over the past two decades. It details modifications done to avoid some problems, along with proposals that could influence future design considerations, particularly for the ESO's Extremely Large Telescope (ELT). Some recurrent problems in the Adapters are analyzed. New designs for the head supports are shared, and a new design for an encoder tape where hydraulic pads are used is suggested. The implementation of encoder signals in a new control system for main axes is also shown.
Show Abstract +
In late 2021 the GTC was equipped with a fully integrated lifting work platform, providing easy and fast access to all telescope tube focal stations, i.e. Cassegrain and four Folded Cassegrain Stations. The platform offers a huge and com-fortable work area, together with a high load capacity and a very short positioning time, complying with industrial safety standards. The highlight is the possibility for the staff to travel with the platform.
The main benefits of the platform are safer work conditions and a shorter maintenance time, without introducing fixed elements in the telescope tube which would have degraded the t
13094-110
On demand | Presented live 18 June 2024
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CFHT continues to make strides toward integrating upgrades within their aging facility in many ways; Instrumentation, Software, Science, etc; but this particular paper focuses on the “Operational” Upgrades that have been recently implemented to continue to make CFHT a top-five observatory in the world.
The Canada-France-Hawaii-Telescope (CFHT- “3.6 meter”) corporation on the summit of Maunakea continues to lead as the “Model” of success competing against much larger Telescopes (2) (KECK-“10-meter”), (GEMINI- “10-meter”) and (SUBARU-“10-meter”) as far as remote capability, published papers, and “Physical” Observatory Site is concerned. Ongoing improvements to our Telescope and Observatory building are what keeps us at the forefront of World-Class Astronomy.
13094-111
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
A machine learning compensator for the SOAR active optics control system is proposed to reduce the convergence time. The compensator uses a deep neural network to predict the mirror shape from sensor measurements and generate actuator commands to correct the mirror shape. Results of a simulated SOAR telescope show that the compensator could reduce the convergence time by up to 90%.
Session PS11:
Posters - Opto-Mechanical Designs
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
View
Tuesday Poster Session schedule and event details
Each day includes a unique set of posters. Poster groupings are listed below by topic.
13094-112
On demand | Presented live 18 June 2024
Show Abstract +
We describe the cryogenic system being developed for Taurus: a super-pressure balloon-born microwave polarimeter scheduled to fly in 2027. The Taurus cryogenic system consists of a 660L liquid helium cryostat which achieves a base temperature of 100mK with the help of a capillary-fed superfluid tank and a closed cycle dilution refrigerator. The main tank is supported with fiberglass standoffs and is encased in two layers of vapor-cooled shields which allow Taurus to make full use of the extended flight time offered by the super-pressure balloon platform. The Taurus cryostat is projected to hold for over 50 days while weighing under 1000lbs. We present the design, testing, and thermal analysis of the Taurus cryogenic systems.
13094-113
On demand | Presented live 18 June 2024
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We present the final design of the cryostat of the Mid-infrared ELT Imager and Spectrograph (METIS) instrument to be operated at ESO’s Extremely Large Telescope (ELT). The cryostat provides the cold optics of the instrument with the required cryo-vacuum environment. The radiation shields of the cryostat are cooled with liquid nitrogen and the cold optics is cooled via pulse-tube coolers down to temperatures between 35 K and 70 K. The cold-warm interface is provided with G10 blades that build together with the top part of the cryostat vessel the structural interface to the cold optics, the warm support structure, and the warm calibration source. The cryostat design is now finalized with most of the parts already produced and final integration almost complete. We present in this paper the final design as manufactured, the key design considerations, and highlights from the integration phase.
13094-114
On demand | Presented live 18 June 2024
Show Abstract +
The new project was called C.2.P.U. (Centre Pédagogique Planète et Univers) and is now dedicated mainly to astronomical and astrophysical research.
The old mirrors were discarded because they were cut to observe exclusively in the infrared, and were replaced by new mirrors obtained by reworking, for economic reasons, two 105 cm diameter Zerodur discs existing at the O.C.A. that had been set aside at the end of the project for which they were used. After the optical work was completed, both mirrors were of excellent quality, but one of them, obtained from a plane-convex Zerodur disc, had a meniscus-shaped blank and was relatively thin (62 mm for a total weight of about 140 kg).The intervention, proposed to reduce the astigmatism introduced in the optics consists of replacing the lateral supports that defined the centering of the mirror with a mechanism that supports the mirror from the central hole present in the mirror. This solution made it possible to greatly reduce astigmatism, improving the optical quality of the observations. The article will present the analyses and results before and after the modification.
13094-115
On demand | Presented live 18 June 2024
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Measurement of the alignment error of the telescope mirrors is an essential and demanding task in the telescope assembly phase. One method is to examine the aberration over the whole telescope field of view from sky images with stars, but many imaging sensors must be arrayed on the focal plane. We propose the concept of a low-cost screen camera for the University of Tokyo Atacama Observatory (TAO) 6.5-m telescope. This system consists of a transparent screen, a camera lens, filters, and a CMOS sensor, and it obtains sky images through the telescope on the screen. The transparent spherical screen with one side sanded is placed at the telescope focal plane. A camera lens, filters, and CMOS sensor capture the starry sky on the screen. After the telescope mirror alignment, the screen camera will provide focused sky images in the whole field of view, 25 arcminutes diameter.
13094-116
On demand | Presented live 18 June 2024
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A double-focus optical telescope (DOT) has been built for public observation and scientific research. The unique optical property of the DOT is that, both the Ritchey-Chretien (R-C) and Prime Focus systems are achieved on one telescope, using a common primary mirror. Switching between the R-C and prime focus systems is accomplished by moving the secondary mirror away from the optical path. The DOT also provides public observations through the eyepiece system.
13094-117
On demand | Presented live 18 June 2024
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The Fizeau type interferometric telescope forms an array of several sub telescopes for direct imaging on the image plane based on the principle of optical interferometry. Comared to the optical long baseline interferometer, this kind of telescope can be used for real time imaging of celestial body due to some excellent characteristics such as sufficient spacial frequencies coverage, single mounting avoided outer optical delay lines and so on. We have built an interferometric imaging telescope with four apertures. Although each aperture size is 100mm, but this telescope can reach a more higher angular resolution which is equivalent to a monolithic telescope of 280mm aperture size through optimal array configuration. Some novel opto-mechanical structure design and error control methods have been applied to this telescope sucessfully. At present, we have finished the final assembly, static co-phasing calibration and verifying of dynamic co-phasing close-loop methods at laboratory. The out-door astronomical observation will be carried out soon.
13094-118
On demand | Presented live 18 June 2024
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Image quality on the NASA Infrared Telescope Facility (IRTF) is currently limited by telescope-induced aberrations when seeing is good. We have measured telescope image quality as a function of telescope pointing over several recent epochs to quantify these aberrations. Using the measured aberrations and seeing, we "Donut" modeled the expected image quality improvements through applications of the soon-to-be commissioned off-axis Shack-Hartmann (S-H) wavefront sensor and CCD camera, FELIX. The average telescope-induced wavefront error without defocus is 0.7 μm RMS, the largest contributor being astigmatism (~ 0.21 μm RMS). Uncorrected images would require ~ 2 times longer integration times to compensate for light loss. Our models indicate that active control of the proposed Adaptive Secondary Mirror (ASM) by a 2x2 S-H in FELIX can accurately measure the largest current aberration (defocus). However, a 3x3 S-H is needed to correct higher-order telescope aberrations.
13094-119
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
Single-mode (SM) fiber-fed spectrographs offer several advantages such as spatial filtering of the wavefront, high spectral resolution, stability and flexibility in instrument design. We present the integration and applications of a SM fiber-fed spectrograph of resolving power ~4000 at 635 nm on the extreme adaptive optics platform of the Subaru telescope (SCExAO).
The spectrograph disperses the outputs of a 19-port visible photonic lantern (PL), a high throughput fiber device that efficiently converts a multimode waveguide to several SM waveguides. With this setup and downstream of extreme adaptive optics, PLs enable high throughput and high resolution spectroscopy. We report on the analysis of the dispersed output flux for image reconstruction of binary sources.
The spectrograph also improves the resolution of the Fiber Imager foR a Single Telescope (FIRST), a visible spectro-interferometer providing high-precision, high-angular-resolution spatial coherence measurements. We report on the sensitivity performance of the upgraded instrument on SCExAO.
13094-121
On demand | Presented live 18 June 2024
Show Abstract +
MISTRAL is a visible and near infrared imager and spectrograph working with the 1.93m telescope at L’Observatoire
de Haute-Provence. The goal of the present project is to design and build one custom lens covering the entire
working band 370 − 1000nm with an enhanced throughput and resolution. The proposed design has the focal
length of 100 mm with f /# = 2 and consists of 5 lenses with 2 aspheres. It is capable to work in spectroscopy
or direct imaging mode with the spectral resolving power up to R590 − 1675 or energy concentration of 84%
within ±1pix. The throughput varies from 79to98% in the main band of 400-1000 nm with a commercial AR
coating and could be yet improved with a custom one. We also demonstrate that with this image quality can be
maintained in a ≤ 10% margin with practically reachable tolerances.
13094-122
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
Transmission spectroscopy has proven to be an effective technique for characterising exoplanet atmospheres. However, only about 1% of the exoplanets are in transiting configuration; hence, characterising exoplanets in their reflected spectrum of host stars will be helpful for a large number of exoplanets. The upcoming extreme large telescopes will be able to study reflected spectra of exoplanets.
Here, we present instrumentation that interfaces the 2.3m Vainu Bappu Telescope prime focus to an existing high-resolution echelle spectrograph with disk-integrated light from solar system objects. One of the primary objectives is to obtain high-resolution, high signal-to-noise reflected spectra from the solar system objects. High-resolution reflected spectra also offer the possibility of resolving the velocity structure in the spectral line profiles arising from exo-moons and exo-rings.
13094-123
On demand | Presented live 18 June 2024
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MICADO, the Multi-AO Imaging Camera for Deep Observation, will be one of
the first light instruments for the 39 m Extremely Large Telescope (ELT) of
the European Southern Observatory (ESO) in Chile on the Cerro Armazones
mountain.
MICADO will operate with different modes (standard imaging, astrometry,
coronagraphy and spectroscopy) in the near infrared (NIR) wavelength
range. The continuous LN2 flow and bath (radiation shields) cryostat, which
will operate at 82 K, is the centerpiece of the instrument, housing all major
subsystems such as the cold optics, the mechanisms with filters and masks,
and the detectors. In this poster we provide a detailed description of the
mechanical manufacturing design of the MICADO cryostat.
13094-124
On demand | Presented live 18 June 2024
Show Abstract +
Detailed Design and First Test Results of the ELT Prefocal Station Hosted Metrology
S. Schmid, E. Aller Carpentier, C. Dupuy, P. Ferreira, S. Guisard, P. Jolley, A. Jost, S. Leveque, S.A.E. Lewis, J. Marrero, H. Sommer
The ELT prefocal stations provide wavefront sensing to support the active control of the telescope during observations; they also include mirrors to distribute the telescope optical beam to the scientific instrument or diagnostic tool that finally uses the light collected by the ELT. Built in to the prefocal stations is a hosted metrology positioning system where metrology measuring instruments including a laser tracker and alignment telescope will be installed. This metrology will be used during coarse alignment of the ELT, to maintain the internal alignment of the prefocal stations, and to locate them with respect to their surroundings. The detailed design and application of these instruments is described here, together with a first set of test results.
13094-125
On demand | Presented live 18 June 2024
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Last generation of large telescopes faces several technical challenges in terms of design, manufacturing, and operation, but also in terms of assembly and maintenance. A new generation of multipurpose devices are required to access M1 to make regular and repetitive alignment, cleaning, and mirror manipulation activities in a reliable and productive way. The Segment Exchange Manipulator, which is being developed for the ELT Telescope, is the first generation of a multipurpose device for telescopes M1 assembly and maintenance operations. Its architecture and modularity make it possible to perform many different operations occurring on M1. Modularity, availability, and reliability are key factors for accurate, safe, and trustworthy operations on different M1 telescopes.
13094-126
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
We present the current design considerations and fabrication techniques used in the LFAST prime focus corrector. The goal of the corrector is to correct for spherical aberration and provide atmospheric dispersion correction as well as provide fast image motion correction; all while maintaining scalability and cost reduction by mass production. We discuss the current status of the assembly and early results.
13094-127
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
Balancing a Takahashi FET-200 Telescope on a one metric ton Takahashi EM-3500 Mount
“When a little is too Much” - Problem Solving by Frederick Garcia
In 2001, a client bought a Takahashi FET-200 f/10 telescope with FS-102 Guide scope on an EM-3500 mount system installed state side. He asked that we substitute his FS-128 for the standard FS-102 guide scope.
The system was installed by Takahashi team in an ObservaDome upgraded with dome slewing and tracking automation.
Dr. Takao Doi with a second Takahashi team arrived at the client’s observatory, and moved the FET-200 forward to the point that the guide scope brackets were up against the tube holder being the tail end was too heavy with the FS-128 guide scope balance in DEC axis. Takahashi designed a ring weight for the dew shield, which in turn required a third RA weight for a final system balance.
13094-128
On demand | Presented live 18 June 2024
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The NSF’s Daniel K Inouye Solar Telescope (DKIST) is the world’s largest solar telescope at the summit of Haleakalā. All large observatories are subject to the negative impacts of vibrations, therefore, one of the goals during the operations and commissioning phase is to collect data to identify and mitigate image jitter. DKIST has five high spatial resolution facility instruments spread across a 16-meter rotating platform. Vibration sources such as moving instrument components, environmental control systems, and active optics can induce image jitter differently across large distances, causing non-common path errors uncorrectable by AO systems. We built a new tool called the Vibrometer, a high speed image tracker designed to measure image motion in order to assess the system optical vibrations at 2kHz rates. We will present how the Vibrometer played a vital role in eliminating the image jitter observed in the Visible Spectro-Polarimeter (ViSP) instrument's slit scanning images. The image jitter was caused by mechanical motion of the Visible Broadband Imager's (VBI) large two-axes camera stage while performing image mosaic scans during simultaneous measurements.
13094-129
On demand | Presented live 18 June 2024
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In this work we present the practical experiences and results obtained in the manufacturing of the tools and equipment needed for the handling of the mirrors, the operation and the maintenance of the Colibrí fast alt-az telescope. These tools and equipment include those used for the mounting and dismounting the M1, M2, and M3 mirrors and DDRAGO/CAGIRE instrument of the Colibrí telescope and for moving them from the observing room floor to the ground level outside the building, and then to the vacuum chamber for aluminization. Also, it includes the tools we used to balance the instrument attached to the Nasmyth station and those used in the cleaning process of the mirrors. Our designs confronted the problem of handling and maintenance of the components in the very limited space available in the building and at the dome of the Colibrí fast alt-az telescope.
13094-130
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
Show Abstract +
The Atacama Large Aperture Submillimeter Telescope (AtLAST) is a proposed project for a 50-m large, single-dish Ritchey-Chétrien observatory located at 5000 m altitude in northern Chile, covering an unprecedent wide range of frequencies, 30 GHz to 1 THz. The highest frequencies observations require an exquisite control of systematics which would ensure a good control of the directivity, beam shape and mitigation of sidelobe level. Proprietary software such as TICRA-Tools can be used for full-wave, complex-field simulations of large optical systems that account systematics such as the panel gaps pattern, supporting struts, thermal and self-weight stress deformations. The approach adopted by TICRA-tools is know as Physical Optics and it computationally expensive when a very large system like AtLAST is analyzed. We present here a set of Physical Optics results which allow us to estimate the performance of the telescope in terms of beam shape, directivity, sidelobes level and stray light, as well as the caveats to shorten the running times.
13094-131
On demand | Presented live 18 June 2024
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The 2-m Ring Solar Telescope (RST) of the Yunnan Astronomical Observatory (YAO) is a new-generation solar telescope that will provide high-resolution solar observations. The RST is now under commissioning on the YAO campus. The secondary mirror of the RST is a 0.6-m diameter convex mirror that is supported by a hexapod system which is to provide precise and stable positioning and alignment of the secondary mirror. We present the development of the hexapod system, including its technical requirement, workspace, actuator and joint design. The classic Stewart type configuration is adopted for the hexapod design and the stepmotor-ballscrew concept for the actuator design. The one-part 2D flexure concept is used to manufacture the Hooke’s joints and also used for 3D rotary joint design. We also describe the performance tests of the hexapod system in laboratory. The hexapod is able to cover a sphere of sf7 mm. The translational displacement resolution is down to 0.1 um, and repeatability <0.1 um RMS, the rotational displacement resolution is down to 0.5 arcsec with repeatability <0.1 arcsec RMS. Besides, the hexapod exhibits high stiffness over 60 Hz with a payload of 70 kg.
13094-132
On demand | Presented live 18 June 2024
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Jiao Tong University Spectroscopic Telescope (JUST) is a 4.8-m wide-field spectroscopic telescope at the Lenghu site in Qinghai Province of China. The primary mirror of JUST adopts the latest segmented mirror active optics technology, which is composed of 18 hexagonal segments with a diameter of 1.1 meters each. JUST is a composite astronomical telescope that combines precision measurement of small target fields with spectral survey of large fields of view. The focal stations of JUST feature two Nasmyth foci, where three types of instruments are installed to conduct spectroscopic observations in order to explore the dark universe, trace the dynamic universe, and search for exoplanets. One station with a 10 arcmin field of view will be installed the high-resolution imaging and spectroscopic instruments, the other station featuring a wide-field and atmospheric dispersion corrector with a 1.2 degree field of view will be used for spectroscopic survey to search for stars and galaxies, etc. The wide-field Nasmyth focus will operate at wavelengths 0.35-1.3µm at the zenith distance of 0- 60°.The two Nasmyth foci can be switched by rotating the tertiary mirror .
13094-133
On demand | Presented live 18 June 2024
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The FPGA firmware is a pivotal element in the NFIRAOS Deformable Mirror Electronics (NDME), enabling real-time functionality of the NDME system. This paper details the design of the FPGA firmware, highlighting the implementation and functionality of its various blocks. We emphasize the firmware’s capability in handling concurrent processing of NDME commands, ensuring adherence to strict timing requirements. The firmware uniquely incorporates the lowest latency SPI interface, DAC, ADC, and a custom 1G Ethernet interface, each meticulously tailored to enhance NDME operations. Our narrative underscores the firmware's proficiency in concurrently processing NDME commands while strictly adhering to demanding timing constraints. By utilizing the Xilinx Kria K26 FPGA for comprehensive benchmarking, we present empirical evidence of the firmware's exceptional capability in managing data transmission and processing latencies. The results, demonstrating adherence to the critical 75-microsecond threshold, validate the firmware's extraordinary efficiency, robustness, and reliability, vital for the TMT project's success.
13094-134
On demand | Presented live 18 June 2024
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We present the current research status of the COSMOS (Capillary-Operated Space Mesoporous Optical System) project, funded by DARPA. The system includes a unique non-rotating liquid mirror within a mesoporous structure with ferrofluid and a thin metallic liquid layer. Capillary forces in the mesoporous structure shape a paraboloidal surface, and any residual shape departure are corrected by magnetic control from an electromagnetic coil array. Our simulations using MATLAB and COMSOL demonstrate control of the meniscus and slew rate within a N-by-N unit cell (1 unit cell is a capillary or a pore). Expanding on these findings, full-scale simulations highlight the system's ability to achieve the desired tilt, locally control the fluid surface, and manage wavefront control.
13094-135
On demand | Presented live 18 June 2024
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The development of scalable, large diameter, and tippable telescope mirrors that do not require glass substrates will usher in the next generation of astronomical observational capabilities. Electrostatic adhesion of liquid mercury to a substrate to generate the reflective surface is a technical solution capable of enabling this new scaling effort to build mirrors of the 50m diameter class. The design will offer scalability, cost-efficiency with off-the-shelf components, and independence from force vectors, diverging from traditional glass optics. Topics to be discussed include gravity's impact, dish deflection, wetting effects, edge effects, 0.5-m mirror design, scaling challenges to 10s of meters, and the influence of voltage and dielectric thickness on the mercury layer.
Acknowledgement
This material is based upon work supported by the Air Force under Contract No. FA237724CB009 under the DARPA Zenith program.
Disclaimer
The views, opinions, and/or findings expressed are those of the author(s) and should not be interpreted as representing the official views or policies of the Department of Defense or the US Government.
13094-136
On demand | Presented live 18 June 2024
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High precision sub-arcsecond pointing stability has become a capability widely utilized in the balloon-borne community, in particular for high resolution optical systems. However, many of these applications are also pushing the state-of-the-art with regards to detector technology, many forms of which require some level of cryogenic cooling and active dissipative cooling systems to achieve target performance specifications. Built on the success of the Super-pressure Balloon-borne Imaging Telescope (SuperBIT) experiment, we present the results of improved technologies and design methodologies applied to the EXoplanet Infrared TElescope (EXCITE), which uses active cryogenic systems to achieve detector performance while requiring pointing stability at the 100 milliarcsecond level. Results from EXCITE’s recent balloon-borne campaign are presented within the context of Super-pressure Balloon (SPB) and Long Duration Balloon (LDB) applications.
13094-137
On demand | Presented live 18 June 2024
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The Super-pressure Balloon-borne Imaging Telescope (SuperBIT) is a diffraction-limited 0.5 m telescope that launched via NASA’s super-pressure balloon technology on April 16, 2023. SuperBIT achieved precise pointing control through the use of nested frames and a Fine Guidance System (FGS), resulting in an image stability of 0.055" over 300 s exposures. The SuperBIT FGS includes a tip-tilt mirror that corrects for jitter on a pair of focal plane star cameras. In this paper, we leverage the flight data from SuperBIT's 45-night mission to inform the FGS design for the next-generation balloon-borne telescope. The Gigapixel Balloon-borne Imaging Telescope (GigaBIT) is designed to be a 1.35m wide-field, high resolution imaging telescope, with specifications to extend the scale and capabilities of SuperBIT. A description and analysis of the SuperBIT FGS will be presented along with methodologies for extrapolating this data to enhance GigaBIT's FGS design and control algorithm. We employ a systems engineering approach to formalize the design constraints for GigaBIT’s FGS. Moreover, an integrated model of the FGS is defined from ray-tracing theory and used for control design.
13094-138
On demand | Presented live 18 June 2024
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The Advanced Space-based Solar Observatory (ASO-S) was successfully sent to space from Jiuquan Launch center on Oct. 9, 2022. It is dedicated to study solar flares, corneal mass eruptions and their connections with solar magnetic field and configured three instruments: a Full-disk solar vector MagnetoGraph (FMG), a Lyman-alpha Solar Telescope (LST), and a solar Hard X-ray Imager (HXI). The HXI is one of the three key parts in this mission and adopts a spatial modulation technique to indirectly achieve image of solar hard X-rays. It is made up of a collimator, a spectrometer and an electrical control box. As the critical component, the collimator is responsible for incident x ray modulation. This paper presents detailed design of HXI, especially the core part collimator. Secondly, ground tests, including characterization and spatial environmental tests of HXI collimator will be reported accounted for its indirect imaging principle. We will put forward some newly on-orbit results in the past one year. All design and test result as well as on orbit performance verifies that this equipment fully completed its expected goal and even presents a more wonderful status over expectations.
13094-222
On demand | Presented live 18 June 2024
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The Rubin Observatory M1M3 Mirror Cell Assembly provides positioning, support, figure correction and temperature control to the primary and tertiary mirror.
Final assembly, integration and tests were successfully performed on site in Chile using a surrogate mirror and then integrated on the telescope mount assembly for system performance test.
This paper will describe the overall system including the improvements that were implemented on site, the modeling developed for testing its performance and selected performance results from the on-site testing.
Session PS12:
Posters - Robotic Telescopes
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
View
Tuesday Poster Session schedule and event details
Each day includes a unique set of posters. Poster groupings are listed below by topic.
13094-139
On demand | Presented live 18 June 2024
Show Abstract +
The Transneptunian Automated Occultation Survey (TAOS II) aims to detect serendipitous occultations of stars by small (∼0.2 to 30 km diameter) objects in the Trans-Neptunian region and beyond. Such events are very rare (expected measurable event rate around 0.001 events per star per year or less) and short in duration (∼200 ms), so many stars must be monitored at a high readout cadence in order to detect events. TAOS II will operate three 1.3 meter telescopes at the Observatorio Astronómico Nacional at San Pedro Mártir in Baja California, México. With high speed cameras comprising CMOS imagers and a field of view of 2.3 sq. deg., the survey will monitor as many as 10,000 stars simultaneously with all three telescopes at a readout cadence of 20 Hz. Installation of the TAOS II cameras was completed in 2023, and the final steps in the commissioning of the survey will be completed in 2024 April. In this talk, the observing system will be described and test results on the system performance will be presented.
13094-140
On demand | Presented live 18 June 2024
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DeepSpec is a novel R~650 broad-band (365nm-900nm) spectrograph planned for the Weizmann Multi-Aperture Spectroscopic Telescope (MAST). MAST is an array of twenty 60 cm PlaneWave telescopes, capable of either acting as a single 2.7m telescope or multiplexing over the entire sky using smaller flexible groups. This approach will make the combination of MAST/DeepSpec a unique facility worldwide in terms of its low cost, flexibility and efficiency, capable of observing up to hundreds of targets per night spread over large areas. With an end-to-end throughput of >65%, DeepSpec will be able to observe targets fainter than 20.5 mag in a 15-min exposure using all telescopes, or tens/hundreds of spectra per hour of 18-19 magnitude targets using smaller groups of telescopes – making it an ideal instrument for time-domain astronomy. DeepSpec is currently in the assembly, integration and testing phase and is planned to start on-sky commissioning by summer of 2024.
13094-141
On demand | Presented live 18 June 2024
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Neural Radiance Fields (NeRFs) have become a benchmark for 3D modeling. Despite their impressive capabilities, the performance of NeRFs is largely dependent on the quality of the input images. To address this, we propose integrating superresolution techniques with NeRFs to enhance 3D model fidelity. Our approach employs exposure correction to overcome model convergence failures resulting from geometric inconsistencies in Generative Adversarial Network (GAN) outputs. While previous studies have explored geometric consistency using refinement networks and inverse degradation pipelines, our solution seamlessly connects image restoration to the ultimate goal of 3D reconstruction. We report an improvement of 0.1065 in LPIPS across our degradation levels and models.
13094-142
On demand | Presented live 18 June 2024
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The DOSSA (Decentralization of Space Situational Awareness) project, a collaborative effort between SpaceAble, Unistellar, and the Laboratoire d’Astrophysique de Marseille, focuses on advancing space surveillance through a global network of amateur astronomers, researchers, and industrial partners. The goal is to improve space situational awareness in the face of increasing satellite numbers by accumulating vast data from Unistellar's distributed telescope network.
The project emphasizes creating a precise sky map of objects orbiting Earth by gathering significant data through Unistellar's telescopes, primarily focused on developing innovative algorithms to broaden detection thresholds. Utilizing a dedicated Convolutional Neural Network, trained on diverse datasets comprising actual sky observations and synthetic satellite trails, the project aims for enhanced sensitivity in detecting fainter orbital objects with superior precision on their orbital parameters.
This study aims to surpass current detection methods and proposes a comparative study against established algorithms.
13094-143
On demand | Presented live 18 June 2024
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LOCNES is a Solar telescope designed to observe the Sun as a star. It feeds the Sun’s light into the NIR spectrograph GIANO-B through a 40-m patch of optical fibers. LOCNES has been designed to obtain high signal-to-noise ratio spectra of the Sun as a star with an accurate wavelength calibration through molecular-band cells. We will extract several disc-integrated activity indicators and average magnetic field measurements for the Sun in the NIR. These parameters will then be correlated with both the RV of the Sun as a star and the resolved images of the solar disc in visible and NIR. It has been installed in the outer part of the TNG dome and started its operation in the 2023 Springtime when we performed the LOCNES commissioning.
13094-144
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
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Spektr-UF mission will make observations with spectrographs and imagers in UV (115-310 nm). Generally, most of applications will require ground support observations. For these purposes we are upgrading existing facilities of observatories of the Institute of Astronomy RAS, and installing new ones. The 1-m and 2-m telescopes will be equipped by echelle spectrographs. Here we present detail information on such instrumentation and our recent achievements.
13094-145
On demand | Presented live 18 June 2024
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Argus Pathfinder is a wide-field optical survey designed to discover transient events via sub-minute deep imaging. Pathfinder integrates up to 38 small-aperture telescopes into a single tracking mount and is also a 1:20 scale prototype for the planned 900-telescope all-sky Argus Optical Array. Optimizing and maintaining image quality for this many optical assemblies is challenging. Each assembly must be carefully collimated, tilt-aligned, and focused to micron-level precision and remain stable over months-long timescales. These calibrations will be achieved with a custom focuser design coupled with robotic actuation and dedicated software tools and preserved by operating the array in a lab-like enclosure, limiting the need for cleaning and maintenance. We present the performance of Argus Pathfinder’s climate-control system (in continuous operation for a year as of December 2023), our custom focuser design, and the development of the automated calibration process tested on Pathfinder for full deployment on the Argus Optical Array.
Session PS13:
Posters - Site Characterization
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
View
Tuesday Poster Session schedule and event details
Each day includes a unique set of posters. Poster groupings are listed below by topic.
13094-146
On demand | Presented live 18 June 2024
Show Abstract +
The Royal Commission for AlUla (RCU) in the Kingdom of Saudi Arabia has developed a robust and sustainable framework that is aligned with the Kingdom’s Vision 2030 goals including economic diversification, local job creation and skills development. The RCU is currently thriving to deliver an environmentally and historically conscientious transformation of AlUla, that advances the understanding of 200,000 years of its cultural heritage.
The RCU is collaborating with local partners and international institutions to develop AlUla Manara to become a renowned astronomical observatory through combining Astro-Tourism offerings and a proficient astronomical observatory. In this context, efforts are currently underway to characterize the site proposed to host the astronomical observatory.
In this paper, we show preliminary astro-meteorological results from the parameters database, based on a computational model using data from the ECMWF Fifth generation reanalysis (ERA5), as well as insights of the Astronomical Site Monitor deployment. The results from the site characterization campaign will be used to design, build and put in operation the future 4m-class optical telescope.
13094-147
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
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After the availability of a clear sky, seeing is the most important parameter to characterize any new astronomical sites. Considering the need to identify a few good candidate sites for India’s large optical telescope project, we have developed a fully robotic DIMM seeing monitor. Our DIMM system uses a 12-inch Meade telescope, a Lucid Vision CMOS camera, and a varieties of sensors to support fully unmanned operation. One of the DIMM system has been permanently installed at IAO observatory, which is 4500m above sea level whereas, other mobile DIMM systems have been used in campaign mode in the near by mountain peaks as tall as 5300m. Simultaneous measurements of the seeing have been carried at different heights. We present the details of our DIMM systems as well as seeing measurements carried out at IAO Hanle and a few other places. We have also attempted to explore any correlation exist between DIMM seeing with other ground and space based meteorological parameters.
13094-148
On demand | Presented live 18 June 2024
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The prediction of the atmospheric and turbulence conditions holds considerable importance for both the astronomical community and free space optical telecommunications. To address these challenges, a numerical approach based on the Weather Research and Forecasting (WRF) model, coupled with an optical turbulence model, has been used for predictions above the Calern site. In earlier publications, our team demonstrated that the results of the predictions have shown good agreement compared to measurements from the Calern Atmospheric Turbulence Station (CATS). However, a disparity persists within the first 500 meters of the atmosphere. To enhance the accuracy of the ground layer predictions, an optimization process is being implemented. We have employed an unmanned aircraft system (UAS) equipped with a nacelle containing instruments to measure the meteorological parameters, within the first 500 meters above the ground. The obtained data will enhance initial simulation conditions, leading to an improvement in the turbulence prediction.
13094-149
On demand | Presented live 18 June 2024
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Low sky brightness is crucial for ground-based astronomical observations, since it limits the observational capability to detect fainter sources. Lenghu, located on the Tibetan Plateau in China, has recently been proved as an excellent astronomical site, including dark sky in optical. In this work, we will report the preliminary results of sky brightness measurements in near-infrared at Lenghu. We apply a wide-field small telescope with InGaAs camera to measure the sky background, as well as variables for time-domain astronomy. We tested the system in J band in August 2023, and we will carry out a long-term monitoring of near-infrared sky brightness in both J and H bands, starting from the upcoming winter season.
13094-150
On demand | Presented live 18 June 2024
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A modular water vapour radiometer (WVR) is presented. This WVR can be used to compare different K-band radiometer topologies and calibration techniques to quantify calibration errors and establish other performance metrics. The base configurations include homodyne, super-heterodyne, and direct detection receivers, while the selectable calibration techniques include internal and external noise sources and tipping-curve calibration.
13094-152
On demand | Presented live 18 June 2024
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The precipitable water vapor (PWV) strongly affects the quality of data obtained from millimeter- and submillimeter-wave astronomical observations, such as those for cosmic microwave background (CMB) measurements.
In this presentation, I will introduce the PWV measurement method using Global Navigation Satellite System (GNSS).
Compared to other PWV measurement methods, GNSS instruments are robust in bad weather conditions, have sufficient time resolution, and are less expensive.
By demonstrating PWV measurements with good accuracy using GNSS instruments in the Atacama Desert, which has low PWV conditions, I will show that GNSS instruments are valuable tools for PWV measurements for observing site evaluation and data analysis for ground-based telescopes.
13094-153
On demand | Presented live 18 June 2024
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The European Solar Telescope (EST) will be built at the Observatorio del Roque de los Muchachos, a site known for its excellent atmospheric seeing conditions. The fundamental design of EST lies on two premises to improve the local seeing: placing the primary mirror as far as possible from the ground layer and using an open-air configuration. In this setting, the telescope will benefit from undisturbed wind allowing natural ventilation. These considerations aim to optimize the site conditions; however, the design itself may introduce local seeing. As the design evolves from conceptual to preliminary phase, the shape of the EST has profoundly changed, and the fundamental aspects shall be re-evaluated. In this article, strategic aspects of the current design are studied, including elements from the telescope structure, the pier, and the enclosure. These trade-offs considered the local seeing as a driving force seeking to optimize the optical performance and provide feedback to the current design of EST.
13094-154
On demand | Presented live 18 June 2024
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The European Solar Telescope (EST) is a 4.2-m solar telescope, currently in the preliminary design phase. As EST will operate in open configuration, directly exposed to the wind, a comprehensive wind tunnel testing campaign has been carried out to correlate the results obtained from Computational Fluid Dynamics Analysis. Additionally, the wind contribution to pointing and tracking error budget has been consolidated. This paper describes the generation of prototypes, the model philosophy, the different tests carried out and the results, all with the aim of correlating the models and thus, to verify the compliance with the requirements of the telescope.
13094-155
CANCELED: All sky photometric monitoring at Las Campanas Observatory (LCO)
18 June 2024 • 17:30 - 19:00 Japan Standard Time | Room G5, North - 1F
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We are developing an all sky camera for photometric monitoring at Las Campanas Observatory (LCO) . The camera consists of a ZWO ASI16200MM Pro monochromatic cooled CMOS detector, a filter wheel and Canon 8-15mm f/4 zoom fisheye lens. The full field 180deg field covers a circle of 3260 pixels diameter on the detector. The plate scale at the center is 3arcmin/pix. We present astrometric mapping, photometric calibration and magnitude limits for the system. The goal of the system is to provide all sky throughput measurements throughout the night.
13094-156
On demand | Presented live 18 June 2024
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The study introduces a technique and apparatus for assessing the atmospheric optical turbulence profile, utilizing the ring image obtained at the focal plane of a telescope fitted with a cone lens. Inversion is used to restore the turbulence profile, by analyzing the link between the wavefront scintillation signal's angular power spectrum and the turbulence's intensity and weight function at a certain altitude. Remarkably, the suggested optical apparatus shows an absence of chromatic aberration throughout its full spectral span (400-1000nm). Given that the achromatic annular image's imaging surface aligns with the telescope's focal plane and the lens barrel is made of carbon fiber, the ring image's image quality remains unaffected by significant temperature variations, eliminating the necessity for additional focusing equipment. This method provides an economical solution with an uncomplicated hardware framework that is straightforward to set up and modify.
13094-157
On demand | Presented live 18 June 2024
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The SoSci and LuSci devices are based on the weak scintillation of extended sources, making them ideal for evaluating near-ground optical turbulence and calibrating other instruments. This paper presents the development of two side-by-side SoSci and two LuSci systems. There is minimal discrepancy in measurement data between the two scintillometers with the same configuration when used simultaneously in the same location. Comparative testing of these scintillometers demonstrates improved measurement accuracy when utilizing real-time solar and lunar images for weight function calculation. Even in the absence of turbulence out-scale data, the scintillometers reliably measure turbulence below 100-200 meters near the ground. Additionally, seeing trends measured by LuSci and DIMM concurrently at the same site are consistent, indicating that ground layer turbulence dominates the total turbulence.
13094-158
On demand | Presented live 18 June 2024
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Ground layer atmospheric turbulence significantly affects the performance of ground-based large-aperture optical telescopes and the related design of adaptive optics systems. This paper compares the Low-Layer SCIDAR (LOLAS) and Lunar Scintillometer (LuSci) methods for characterizing the turbulence profile at the ground layer. A testing campaign was conducted at the Xuyi Observation Station of Purple Mountain Observatory in China in October 2023.
The paper presents ground layer turbulence profiles obtained simultaneously by LOLAS and LuSci, and compares their integrated seeing at various altitudes from the ground, as well as the average height of various percentiles of
ground layer strength. The results show a high degree of agreement, with LOLAS providing slightly higher values under 2ms exposure time but lower values under 5ms exposure time. Approximately 75% of the ground layer (0-250m) turbulence strength is generated below 50 meters. These methods can be directly used for site testing for the proposed Chinese Large Optical / Infrared Telescope.
Show Abstract +
The atmospheric turbulence measurement is an essential information for high-angular resolution imaging in astronomy, and for optical link. Since 2015, the CATS station monitors atmospheric conditions at the Calern observatory, during both daytime and nighttime from the ground to the top of the atmosphere. The station is fully autonomous and is equipped with a set of instruments to continuously monitor optical turbulence. The Profiler of Moon Limb measures, from Sun or Moon limbs observation, the vertical profiles of the refractive index structure constant Cn2 with a high vertical resolution. The Generalized DIMM monitors the integrated turbulence parameters by observing bright stars. More recently, knowing the need of turbulence forecasting, we developed a system integrated in the CATS station to daily predict daytime and nighttime meteorological and optical turbulence conditions for the next 48h. We also have designed an instrumental platform attached to a drone and allowing to measure, with a high resolution, the weather conditions between the ground and an altitude of around 500m. Recently we have improved the station by adding instrument to better monitor the cloud conditions.
13094-160
On demand | Presented live 18 June 2024
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The Simons Observatory is a ground-based telescope array located at an elevation of 5200 meters, in the Atacama Desert in Chile, designed to measure the temperature and polarization of the cosmic microwave background. It comprises four telescopes: three 0.42-meter small aperture telescopes (SATs), focused on searching for primordial gravitational waves, and one 6-meter large aperture telescope, focused on studying small-scale perturbations. Each of the SATs will field over 12,000 TES bolometers. Prior to their deployment in 2023 and 2024, the optical properties of each SAT are characterized in the laboratory. We report here on measurements of beam maps acquired using a thermal source on SAT-MF1, along with measurements of near-field beam maps using a holographic method that enables characterization of both the amplitude and phase of the beam response, yielding an estimate of the far-field radiation pattern received by the telescope. The success of the holography and thermal beam map experiments confirmed the optical performance were sufficient to meet the science requirements. SAT-MF1 was deployed to Chile in June, 2023. On-site observations are currently underway.
13094-161
On demand | Presented live 18 June 2024
Show Abstract +
Dome A is one of the best astronomical observatory sites on the earth. Unlike any other area, the telescopes have to be settled on the snow ground. In that case, it is very important to analysis the Snow mechanics in Dome A. This article first compares five methods previously used for analyzing snow strength, and selects the most suitable method to estimate the snow strength in Dome A.Through this method, combined with the temperature and density data at different depths in the Dome A area, the paper estimates the strength of the surface snow is ranging from0.6Mpa to 2.5Mpa(0-10m depth), and by the ultrasonic velocity measurements, the elastic modulus of the snow in Dome A has also been estimated at the range from 4 Mpa to 600 Mpa.Finally, the size of the wood foundation and the tilt angle of the snow surface under the wind speed of 10m/s were calculated by the static analysis. According to the tilt angle analysis, it was found that the elastic modulus of the original snow is too low to meet the requirements of tilt angle for the 2m class telescopes, and the snow foundation needs to have a densification treatment to make its density up to 530kg/m3.
Digital Posters
The posters listed below are available exclusively for online viewing during the week of SPIE Astronomical Telescopes + Instrumentation 2024.
13094-168
On demand | Presenting live 21 June 2024
Show Abstract +
This paper discusses the refrigerant services infrastructure in development for the Thirty Meter Telescope (TMT), to remove waste heat generated by electronics on the telescope top end, cool the adaptive optics enclosures to -30°C, and cool the telescope hydrostatic bearing oil to -21°C. We discuss the trade study that led to the choice of carbon dioxide as the refrigerant. We describe the TMT refrigeration cooling requirements, selection of refrigerant, conceptual design, and concept of operations.
Program Committee
Research School of Astronomy & Astrophysics, The Australian National Univ. (Australia)
Program Committee
Inter-Univ. Ctr. for Astronomy and Astrophysics (India)
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Courses at Astronomical Telescopes + Instrumentation
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See courses on topics related to Ground-based and Airborne Telescopes.
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