Browsing by Type "inproceedings"

The CEntral (field) Three-mirror Anastigmat (CETA) telescope is designed on the specifications of the proposed Theia mission, aiming at high precision differential astrometry over a large field, for exo-planetary system characterization and dark matter /dark energy search through the dynamics of star clusters. Usually, Three Mirror Anastigmat designs are either off-axis in terms of field, or decentered in terms of pupil. We propose a family of solutions using fully centred optics and a large on-axis field, at the expense of a non negligible central obscuration. We analyse in particular a 1 m class compact telescope, with 15 m effective focal length, i.e. suited to small pixel (4-6 μm) CMOS detectors operating in the visible and near IR. Due to the underlying symmetry, the resulting optical response is quite good over a 14 arcmin radius field, and it is of special interest to astrometry applications. Also, manufacturing, alignment and calibration can be expected to benefit significantly; some basic aspects are preliminarily considered.

This work presents the application of machine learning to the estimation of Adaptive Optics (AO) parameters using telemetry data from the AO system. To improve the estimation accuracy of the Strehl ratio, seeing, wind speed and outer scale, we leverage the capabilities of Recurrent Neural Networks (RNNs). Estimating these optical performance and atmospheric parameters is a key problem in AO. Another critical aspect is obtaining a measure of these quantities as seen from the Wavefront Sensor (WFS) itself, which provides a precise indication of their impact on the image quality. Analytical approaches to compute some of these quantities from WFS telemetry data have been proposed in the literature; however, some parameters are difficult to estimate and measure and may require approximations that limit the estimate's reliability. In recent years, other statistical approaches based on the large amount of data available in WFS telemetry have become feasible. In this contribution, we propose a novel approach based entirely on machine learning algorithms. These algorithms utilize the data produced by the WFS (mirror commands in our case) to perform the task. We then compare our results to the state-of-the-art methods. This preliminary approach uses simulated SOUL (LBT AO system) data generated by the PASSATA software: in the future we plan to implement a similar approach on real data.

The ASTRI Mini-Array is an international collaboration, led by the Italian National Institute for Astrophysics (INAF), devoted to the construction, deployment and operation of a set of nine identical dual-mirror Cherenkov telescopes, for very-high-energy gamma-ray astronomy. The ASTRI telescopes will be characterized by innovative technological solutions, such as the dual-mirror Schwarzschild-Couder optical configuration, a modular, light and compact focal-plane camera consisting of an array of multi-pixel silicon photo-multiplier sensors, and an efficient and fast front-end electronics, specifically designed for ASTRI. They will be located at the Teide Astronomical Observatory, operated by IAC, in the Canary island of Tenerife.

<br clear="all"/> The secondary mirrors of the ASTRI telescopes were realized already at the beginning of the ASTRI Project. After a few years, some of them revealed a clear degradation of the surface reflective coating. Therefore, it was necessary to look for a qualified industrial supplier able to perform a new coating of these mirrors. To this aim, the ASTRI Collaboration identified the French company CILAS as the best option. In this paper, we present the activities performed by CILAS on the mirrors. We first describe the coating approach adopted by CILAS and its tuning to the case of the ASTRI M2 mirrors. Then, we describe the qualification activities of the coating process, the problems arisen and the remedial actions that were adopted. Finally, we report the obtained results from the reflectivity and homogeneity points of view.

The ASTRI Stellar Intensity Interferometry Instrument (SI3) is a fast single photon counting instrument for performing intensity interferometry observations of bright stars with the ASTRI Mini-Array. SI3 is designed to perform accurate measurements of single photon arrival times (1ns) in a narrow optical bandwidth (1-8nm) centered at a wavelength in the range 420-500nm. The instrument will exploit the 36 simultaneous baselines over distances between 100m and 700m of the ASTRI Mini-Array to achieve angular resolutions below 100 microarcsec. At this level of resolution it turns out to be possible to reveal details on the surface and of the environment surrounding bright stars on the sky. During 2023 SI3 underwent a significant redesign, with an optical fiber positioned on the focal plane to feed the detectors and electronics. Here we present this new baseline design of SI3, and the motivations behind this choice, including the possibility of future upgrades of the instrument with dedicated front-end electronics and channel multiplexing. We will also show the first results of the target selection procedure based on simulations. Stars with angular diameters of less than 500- 600 microarcseconds up to about magnitude 4.5 will be observable. Thanks to the 36 simultaneous baselines, accurate (up to ∼1%) angular measurements can be obtained with 10-30 hours of observations. This accuracy can rival with that obtained with other arrays of Cherenkov telescopes, despite the smaller collecting area of a single ASTRI telescope.

The ASTRI Stellar Intensity Interferometry Instrument (SI3) is a fast single photon counting instrument for performing intensity interferometry observations of bright stars with the ASTRI Mini-Array. SI3 is designed to perform accurate measurements of single photon arrival times (1ns) in a narrow optical bandwidth (1-8nm) centered at a wavelength in the range 420-500nm. The instrument will exploit the 36 simultaneous baselines over distances between 100m and 700m of the ASTRI Mini-Array to achieve angular resolutions below 100 microarcsec. At this level of resolution it turns out to be possible to reveal details on the surface and of the environment surrounding bright stars on the sky. During 2023 SI3 underwent a significant redesign, with an optical fiber positioned on the focal plane to feed the detectors and electronics. Here we present this new baseline design of SI3, and the motivations behind this choice, including the possibility of future upgrades of the instrument with dedicated front-end electronics and channel multiplexing. We will also show the first results of the target selection procedure based on simulations. Stars with angular diameters of less than 500- 600 microarcseconds up to about magnitude 4.5 will be observable. Thanks to the 36 simultaneous baselines, accurate (up to ∼1%) angular measurements can be obtained with 10-30 hours of observations. This accuracy can rival with that obtained with other arrays of Cherenkov telescopes, despite the smaller collecting area of a single ASTRI telescope.

The ASTRI Stellar Intensity Interferometry Instrument (SI3) is a fast single photon counting instrument for performing intensity interferometry observations of bright stars with the ASTRI Mini-Array. SI3 is designed to perform accurate measurements of single photon arrival times (1ns) in a narrow optical bandwidth (1-8nm) centered at a wavelength in the range 420-500nm. The instrument will exploit the 36 simultaneous baselines over distances between 100m and 700m of the ASTRI Mini-Array to achieve angular resolutions below 100 microarcsec. At this level of resolution it turns out to be possible to reveal details on the surface and of the environment surrounding bright stars on the sky. During 2023 SI3 underwent a significant redesign, with an optical fiber positioned on the focal plane to feed the detectors and electronics. Here we present this new baseline design of SI3, and the motivations behind this choice, including the possibility of future upgrades of the instrument with dedicated front-end electronics and channel multiplexing. We will also show the first results of the target selection procedure based on simulations. Stars with angular diameters of less than 500- 600 microarcseconds up to about magnitude 4.5 will be observable. Thanks to the 36 simultaneous baselines, accurate (up to ∼1%) angular measurements can be obtained with 10-30 hours of observations. This accuracy can rival with that obtained with other arrays of Cherenkov telescopes, despite the smaller collecting area of a single ASTRI telescope.

In the last decades, Adaptive Optics have gained a great importance in improving the observatories capabilities all over the world, and the complexity and dimensions of deformable mirrors have grown rapidly, making necessary the development of clever ways to perform their optical calibration. Here we propose the study of a procedure based on the accurate local calibration of the position sensors. This approach would have a huge impact on both time and cost with respect to actual approach, consisting in the measurement of the actuators influence functions in full aperture. After the development of a simulation tool, able to prove our idea, we will test the new approach on deformable mirrors which are now under production.

We report results from numerical simulations assessing astrometry measurements with the Multiconjugate Adaptive Optics Relay for ELT Observations (MORFEO) instrument on the Extremely Large Telescope (ELT). Using the Advanced Exposure Time Calculator (AETC), we evaluate MORFEO astrometric accuracy in moderately crowded fields. Our simulations account for spatially variable Point Spread Function (PSF), geometric distortion, and rotation-dependent variations. We computed focal plane coordinates using observed stellar distribution and computed population synthesis with the SPISEA tool, generating stellar magnitude distributions for MICADO filters at selected metallicities and stellar ages. Our analysis shows that MORFEO can achieve high-precision astrometry in the galaxy neighborhood (within μ<24 mag) by minimizing PSF enlargement and optimizing calibration strategies. These results inform future observational campaigns and contribute to the development of astrometric science cases for the ELT.

The road to increasingly more challenging and bigger systems in astronomy is resulting in as much bigger challenges to the safety for people and things. As well for the ELT (Extremely Large Telescope) instrumentation and modules, these big "systems" collaborate and share the same environment and spaces, and, as for the AO module MORFEO (Multi-conjugate adaptive Optics Relay For ELT Observations) and the MICADO camera (Multi-AO Imaging Camera for Deep Observations), some subsystems are strongly embedded, even if they are designed by different consortia. Therefore, the designers are thinking to even more sophisticated systems to assure the safety and communication of information between the different instruments. In this context, the MORFEO consortium is investigating on the possibility to use industrial safety modules, architecturally integrated in the overall control system. This approach can highly help in the fulfilling of even more complex requirements with the high flexibility required to grant the possibility, during the telescope life, of one or more upgrading of the instrumentation and their way to co-operate. The paper goes through a comparison between the in-house designed safety solution, widely used in the past, and the industrial safety systems and the implementation of these technologies in the ground-based astronomy.

The road to increasingly more challenging and bigger systems in astronomy is resulting in as much bigger challenges to the safety for people and things. As well for the ELT (Extremely Large Telescope) instrumentation and modules, these big "systems" collaborate and share the same environment and spaces, and, as for the AO module MORFEO (Multi-conjugate adaptive Optics Relay For ELT Observations) and the MICADO camera (Multi-AO Imaging Camera for Deep Observations), some subsystems are strongly embedded, even if they are designed by different consortia. Therefore, the designers are thinking to even more sophisticated systems to assure the safety and communication of information between the different instruments. In this context, the MORFEO consortium is investigating on the possibility to use industrial safety modules, architecturally integrated in the overall control system. This approach can highly help in the fulfilling of even more complex requirements with the high flexibility required to grant the possibility, during the telescope life, of one or more upgrading of the instrumentation and their way to co-operate. The paper goes through a comparison between the in-house designed safety solution, widely used in the past, and the industrial safety systems and the implementation of these technologies in the ground-based astronomy.

The road to increasingly more challenging and bigger systems in astronomy is resulting in as much bigger challenges to the safety for people and things. As well for the ELT (Extremely Large Telescope) instrumentation and modules, these big "systems" collaborate and share the same environment and spaces, and, as for the AO module MORFEO (Multi-conjugate adaptive Optics Relay For ELT Observations) and the MICADO camera (Multi-AO Imaging Camera for Deep Observations), some subsystems are strongly embedded, even if they are designed by different consortia. Therefore, the designers are thinking to even more sophisticated systems to assure the safety and communication of information between the different instruments. In this context, the MORFEO consortium is investigating on the possibility to use industrial safety modules, architecturally integrated in the overall control system. This approach can highly help in the fulfilling of even more complex requirements with the high flexibility required to grant the possibility, during the telescope life, of one or more upgrading of the instrumentation and their way to co-operate. The paper goes through a comparison between the in-house designed safety solution, widely used in the past, and the industrial safety systems and the implementation of these technologies in the ground-based astronomy.

In the past two years significant forward progress has been achieved in development of Adaptive Optics sensing and control technology needed for the observation modes of the Giant Magellan Telescope1. Most notable is the recent progress in demonstrating the accurate and stable control of segment piston in the diffraction-limited Natural Guide Star AO observation mode. Two NSF-funded testbeds have been successfully operated to validate the control algorithms for active optics, adaptive optics and segment piston in diffraction-limited observation. GMTO also built and operated wavefront sensor prototypes and integrated them with the testbeds. The testing has largely validated the wavefront sensor designs and has retired much of the fabrication and assembly risks. In parallel with the hardware demonstrations, significant progress has been achieved in both NGAO and LTAO control simulations verifying compliance with the required performance in each of these observation modes and thereby supporting the image quality budgets. In the area of design the GMTO Telescope Metrology Subsytem has passed its Preliminary Design Review and the conceptual design of the Adaptive Optics Test Camera has been completed. Finally, a Delta Preliminary Design phase for the LTAO hardware has begun.

AIRS is the infrared spectroscopic instrument of ARIEL: Atmospheric Remote-sensing Infrared Exoplanet Large-survey mission adopted in November 2020 as the Cosmic Vision M4 ESA mission and planned to be launched in 2029 by an Ariane 6 from Kourou toward a large amplitude orbit around L2 for a 4-year mission. Within the scientific payload, AIRS will perform transit spectroscopy of over 1000 exoplanets to complete a statistical survey, including gas giants, Neptunes, super-Earths and Earth-size planets around a wide range of host stars. All these collected spectroscopic data will be a major asset to answer the key scientific questions addressed by this mission: what are exoplanets made of? How do planets and planetary systems form? How do planets and their atmospheres evolve over time? The AIRS instrument is based on two independent channels covering 1.95-3.90 µm (CH0) and 3.90-7.80 µm (CH1) wavelength ranges with prism-based dispersive elements producing spectra of low resolutions R>100 in CH0 and R>30 in CH1 on two independent detectors. The spectrometer is designed to provide a Nyquist-sampled spectrum in both spatial and spectral directions to limit the sensitivity of measurements to the jitter noise and intra pixels pattern during the long (10 hours) transit spectroscopy exposures. A full instrument overview will be presented covering the thermo-mechanical design of the instrument functioning in a 60 K environment, up to the detection and acquisition chain of both channels based on 2 HgCdTe detectors actively cooled to below 42 K. This overview will present updated information of phase C studies, in particular on the assembly and testing of prototypes that are highly representative of the future engineering model that will be used as an instrument-level qualification model.

AIRS is the infrared spectroscopic instrument of ARIEL: Atmospheric Remote-sensing Infrared Exoplanet Large-survey mission adopted in November 2020 as the Cosmic Vision M4 ESA mission and planned to be launched in 2029 by an Ariane 6 from Kourou toward a large amplitude orbit around L2 for a 4-year mission. Within the scientific payload, AIRS will perform transit spectroscopy of over 1000 exoplanets to complete a statistical survey, including gas giants, Neptunes, super-Earths and Earth-size planets around a wide range of host stars. All these collected spectroscopic data will be a major asset to answer the key scientific questions addressed by this mission: what are exoplanets made of? How do planets and planetary systems form? How do planets and their atmospheres evolve over time? The AIRS instrument is based on two independent channels covering 1.95-3.90 µm (CH0) and 3.90-7.80 µm (CH1) wavelength ranges with prism-based dispersive elements producing spectra of low resolutions R>100 in CH0 and R>30 in CH1 on two independent detectors. The spectrometer is designed to provide a Nyquist-sampled spectrum in both spatial and spectral directions to limit the sensitivity of measurements to the jitter noise and intra pixels pattern during the long (10 hours) transit spectroscopy exposures. A full instrument overview will be presented covering the thermo-mechanical design of the instrument functioning in a 60 K environment, up to the detection and acquisition chain of both channels based on 2 HgCdTe detectors actively cooled to below 42 K. This overview will present updated information of phase C studies, in particular on the assembly and testing of prototypes that are highly representative of the future engineering model that will be used as an instrument-level qualification model.

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.

In this work it is evaluated the possibility to use a laser tracker as essential embedded tool for the alignment and for the monitoring of the instrument, or better, evaluate if the uncertainty of the tracker measuring the optical elements stay within the alignment requirements.

The case study presented here is MORFEO which is a first-light instrument for the European Extremely Large Telescope. The study consists in the realization of a software that optimizes the position of the tracker inside the instrument considering the nominal position of the targets measured (SMRs) and the possible vignetting based on the prediction of the accuracy and repeatability of the measurements. This analysis is made by steps: the first one considers the error model gave from the manufacture of the tracker. The second one is based on a series of tests and characterizations performed in laboratory to determine more accurately the performances. The results obtained have been validated using a dummy version of an optomechanical element measured by using a Coordinate Measurement Machine (CMM).

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.

In this work it is evaluated the possibility to use a laser tracker as essential embedded tool for the alignment and for the monitoring of the instrument, or better, evaluate if the uncertainty of the tracker measuring the optical elements stay within the alignment requirements.

The case study presented here is MORFEO which is a first-light instrument for the European Extremely Large Telescope. The study consists in the realization of a software that optimizes the position of the tracker inside the instrument considering the nominal position of the targets measured (SMRs) and the possible vignetting based on the prediction of the accuracy and repeatability of the measurements. This analysis is made by steps: the first one considers the error model gave from the manufacture of the tracker. The second one is based on a series of tests and characterizations performed in laboratory to determine more accurately the performances. The results obtained have been validated using a dummy version of an optomechanical element measured by using a Coordinate Measurement Machine (CMM).

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.

In this work it is evaluated the possibility to use a laser tracker as essential embedded tool for the alignment and for the monitoring of the instrument, or better, evaluate if the uncertainty of the tracker measuring the optical elements stay within the alignment requirements.

The case study presented here is MORFEO which is a first-light instrument for the European Extremely Large Telescope. The study consists in the realization of a software that optimizes the position of the tracker inside the instrument considering the nominal position of the targets measured (SMRs) and the possible vignetting based on the prediction of the accuracy and repeatability of the measurements. This analysis is made by steps: the first one considers the error model gave from the manufacture of the tracker. The second one is based on a series of tests and characterizations performed in laboratory to determine more accurately the performances. The results obtained have been validated using a dummy version of an optomechanical element measured by using a Coordinate Measurement Machine (CMM).

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.

In this work it is evaluated the possibility to use a laser tracker as essential embedded tool for the alignment and for the monitoring of the instrument, or better, evaluate if the uncertainty of the tracker measuring the optical elements stay within the alignment requirements.

The case study presented here is MORFEO which is a first-light instrument for the European Extremely Large Telescope. The study consists in the realization of a software that optimizes the position of the tracker inside the instrument considering the nominal position of the targets measured (SMRs) and the possible vignetting based on the prediction of the accuracy and repeatability of the measurements. This analysis is made by steps: the first one considers the error model gave from the manufacture of the tracker. The second one is based on a series of tests and characterizations performed in laboratory to determine more accurately the performances. The results obtained have been validated using a dummy version of an optomechanical element measured by using a Coordinate Measurement Machine (CMM).

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.

In this work it is evaluated the possibility to use a laser tracker as essential embedded tool for the alignment and for the monitoring of the instrument, or better, evaluate if the uncertainty of the tracker measuring the optical elements stay within the alignment requirements.

The case study presented here is MORFEO which is a first-light instrument for the European Extremely Large Telescope. The study consists in the realization of a software that optimizes the position of the tracker inside the instrument considering the nominal position of the targets measured (SMRs) and the possible vignetting based on the prediction of the accuracy and repeatability of the measurements. This analysis is made by steps: the first one considers the error model gave from the manufacture of the tracker. The second one is based on a series of tests and characterizations performed in laboratory to determine more accurately the performances. The results obtained have been validated using a dummy version of an optomechanical element measured by using a Coordinate Measurement Machine (CMM).