Browsing by Author "Glauser, Adrian M."

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Laboratory experiments of model-based reinforcement learning for adaptive optics control
(2024) Nousiainen, Jalo; Engler, Byron; Kasper, Markus; Rajani, Chang; Helin, Tapio; Heritier, Cédric T.; Quanz, Sascha P.; Glauser, Adrian M.
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Direct imaging of Earth-like exoplanets is one of the most prominent scientific drivers of the next generation of ground-based telescopes. Typically, Earth-like exoplanets are located at small angular separations from their host stars, making their detection difficult. Consequently, the adaptive optics (AO) system's control algorithm must be carefully designed to distinguish the exoplanet from the residual light produced by the host star. A promising avenue of research to improve AO control builds on data-driven control methods, such as reinforcement learning (RL). RL is an active branch of the machine learning research field, where control of a system is learned through interaction with the environment. Thus, RL can be seen as an automated approach to AO control, where its usage is entirely a turnkey operation. In particular, model-based RL has been shown to cope with temporal and misregistration errors. Similarly, it has been demonstrated to adapt to nonlinear wavefront sensing while being efficient in training and execution. In this work, we implement and adapt an RL method called policy optimization for AO (PO4AO) to the GPU-based high-order adaptive optics testbench (GHOST) test bench at ESO headquarters, where we demonstrate a strong performance of the method in a laboratory environment. Our implementation allows the training to be performed parallel to inference, which is crucial for on-sky operation. In particular, we study the predictive and self-calibrating aspects of the method. The new implementation on GHOST running PyTorch introduces only around 700 μs of in addition to hardware, pipeline, and Python interface latency. We open-source well-documented code for the implementation and specify the requirements for the RTC pipeline. We also discuss the important hyperparameters of the method and how they affect the method. Further, the paper discusses the source of the latency and the possible paths for a lower latency implementation.
The Large Interferometer For Exoplanets (LIFE): a space mission for mid-infrared nulling interferometry
(2024-08-28) Glauser, Adrian M.; Quanz, Sascha P.; Hansen, Jonah; Dannert, Felix; Ireland, Michael; Linz, Hendrik; Absil, Olivier; Alei, Eleonora; Angerhausen, Daniel; Birbacher, Thomas; Defrère, Denis; Fortier, Andrea; Huber, Philipp A.; Kammerer, Jens; Laugier, Romain; Lichtenberg, Tim; Noack, Lena; Ranganathan, Mohanakrishna; Rugheimer, Sarah; Airapetian, Vladimir; Alibert, Yann; Amado, Pedro J.; Anger, Marius
A4 Artikkeli konferenssijulkaisussa
The Large Interferometer For Exoplanets (LIFE) is a proposed space mission that enables the spectral characterization of the thermal emission of exoplanets in the solar neighborhood. The mission is designed to search for global atmospheric biosignatures on dozens of temperate terrestrial exoplanets and it will naturally investigate the diversity of other worlds. Here, we review the status of the mission concept, discuss the key mission parameters, and outline the trade-offs related to the mission’s architecture. In preparation for an upcoming concept study, we define a mission baseline based on a free-formation flying constellation of a double Bracewell nulling interferometer that consists of 4 collectors and a central beam-combiner spacecraft. The interferometric baselines are between 10–600m, and the estimated diameters of the collectors are at least 2m (but will depend on the total achievable instrument throughput). The spectral required wavelength range is 6–16μm (with a goal of 4–18.5μm), hence cryogenic temperatures are needed both for the collectors and the beam combiners. One of the key challenges is the required deep, stable, and broad-band nulling performance while maintaining a high system throughput for the planet signal. Among many ongoing or needed technology development activities, the demonstration of the measurement principle under cryogenic conditions is fundamentally important for LIFE.
Large Interferometer For Exoplanets (LIFE): XIV. Finding terrestrial protoplanets in the galactic neighborhood
(2024-12-01) Cesario, Lorenzo; Lichtenberg, Tim; Alei, Eleonora; Carrión-González, Óscar; Dannert, Felix A.; Defrère, Denis; Ertel, Steve; Fortier, Andrea; García Muñoz, A.; Glauser, Adrian M.; Hansen, Jonah T.; Helled, Ravit; Huber, Philipp A.; Ireland, Michael J.; Kammerer, Jens; Laugier, Romain; Lillo-Box, Jorge; Menti, Franziska; Meyer, Michael R.; Noack, Lena; Quanz, Sascha P.; Quirrenbach, Andreas; Rugheimer, Sarah; Van Der Tak, Floris; Wang, Haiyang S.; Anger, Marius; Balsalobre-Ruza, Olga; Bhattarai, Surendra; Braam, Marrick; Castro-González, Amadeo; Cockell, Charles S.; Constantinou, Tereza; Cugno, Gabriele; Davoult, Jeanne; Güdel, Manuel; Hernitschek, Nina; Hinkley, Sasha; Itoh, Satoshi; Janson, Markus; Johansen, Anders; Jones, Hugh R.A.; Kane, Stephen R.; Van Kempen, Tim A.; Kislyakova, Kristina G.; Korth, Judith; Kovačević, Andjelka B.; Kraus, Stefan; Kuiper, Rolf; Mathew, Joice; Matsuo, Taro; Miguel, Yamila; Min, Michiel; Navarro, Ramon; Ramirez, Ramses M.; Rauer, Heike; Vow Ricketti, Berke; Romagnolo, Amedeo; Schlecker, Martin; Sneed, Evan L.; Squicciarini, Vito; Stassun, Keivan G.; Tamura, Motohide; Viudez-Moreiras, Daniel; Wordsworth, Robin D.
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Context. The increased brightness temperature of young rocky protoplanets during their magma ocean epoch makes them potentially amenable to atmospheric characterization at distances from the Solar System far greater than thermally equilibrated terrestrial exoplanets, offering observational opportunities for unique insights into the origin of secondary atmospheres and the near surface conditions of prebiotic environments. Aims. The Large Interferometer For Exoplanets (LIFE) mission will employ a space-based midinfrared nulling interferometer to directly measure the thermal emission of terrestrial exoplanets. In this work, we seek to assess the capabilities of various instrumental design choices of the LIFE mission concept for the detection of cooling protoplanets with transient high-temperature magma ocean atmospheres at the tail end of planetary accretion. In particular, we investigate the minimum integration times necessary to detect transient magma ocean exoplanets in young stellar associations in the Solar neighborhood. Methods. Using the LIFE mission instrument simulator (LIFEsim), we assessed how specific instrumental parameters and design choices, such as wavelength coverage, aperture diameter, and photon throughput, facilitate or disadvantage the detection of protoplan-ets. We focused on the observational sensitivities of distance to the observed planetary system, protoplanet brightness temperature (using a blackbody assumption), and orbital distance of the potential protoplanets around both G- and M-dwarf stars. Results. Our simulations suggest that LIFE will be able to detect (S/N ≥ 7) hot protoplanets in young stellar associations up to distances of 100 pc from the Solar System for reasonable integration times (up to a few hours). Detection of an Earth-sized protoplanet orbiting a Solar-sized host star at 1 AU requires less than 30 minutes of integration time. M-dwarfs generally need shorter integration times. The contribution from wavelength regions smaller than 6 μm is important for decreasing the detection threshold and discriminating emission temperatures. Conclusions. The LIFE mission is capable of detecting cooling terrestrial protoplanets within minutes to hours in several local young stellar associations hosting potential targets. The anticipated compositional range of magma ocean atmospheres motivates further architectural design studies to characterize the crucial transition from primary to secondary atmospheres.