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Gravitational wave (GW) astronomy is witnessing a transformative shift from terrestrial to space-based detection, with missions like Taiji at the forefront. While the transition brings unprecedented opportunities for exploring massive black…

Instrumentation and Methods for Astrophysics · Physics 2024-02-21 Minghui Du , Bo Liang , He Wang , Peng Xu , Ziren Luo , Yueliang Wu

Fermionic quantum processors are a promising platform for quantum simulation of correlated fermionic matter. In this work, we study a hardware-efficient protocol for measuring complex expectation values of the time-evolution operator,…

The Event Horizon Telescope (EHT) has imaged two supermassive black holes, Messier 87* (M87*) and Sagittarius A* (Sgr A*), using very-long-baseline interferometry (VLBI). The theoretical analyses of each source suggest magnetically arrested…

High Energy Astrophysical Phenomena · Physics 2024-07-16 Kaitlyn M. Shavelle , Daniel C. M. Palumbo

The Gaussian process state-space model (GPSSM) has attracted extensive attention for modeling complex nonlinear dynamical systems. However, the existing GPSSM employs separate Gaussian processes (GPs) for each latent state dimension,…

Machine Learning · Computer Science 2023-09-06 Zhidi Lin , Juan Maroñas , Ying Li , Feng Yin , Sergios Theodoridis

The image quality of the new generation of earthbound Extremely Large Telescopes (ELTs) is heavily influenced by atmospheric turbulences. To compensate these optical distortions a technique called adaptive optics (AO) is used. Many AO…

Numerical Analysis · Mathematics 2020-09-03 Bernadett Stadler , Roberto Biasi , Mauro Manetti , Ronny Ramlau

Parameter retrieval and model inversion are key problems in remote sensing and Earth observation. Currently, different approximations exist: a direct, yet costly, inversion of radiative transfer models (RTMs); the statistical inversion with…

Signal Processing · Electrical Eng. & Systems 2021-04-22 Daniel Heestermans Svendsen , Pablo Morales-Alvarez , Ana Belen Ruescas , Rafael Molina , Gustau Camps-Valls

The search for Earth-like exoplanets requires high-contrast and high-angular resolution instruments, which designs can be very complex: they need an adaptive optics system to compensate for the effect of the atmospheric turbulence on image…

Instrumentation and Methods for Astrophysics · Physics 2020-12-16 Lucie Leboulleux , Raphaël Galicher , Eric Gendron , Pierre Baudoz , Gérard Rousset

In this work we study the non-parametric reconstruction of spatio-temporal dynamical Gaussian processes (GPs) via GP regression from sparse and noisy data. GPs have been mainly applied to spatial regression where they represent one of the…

Machine Learning · Computer Science 2020-10-06 Marco Todescato , Andrea Carron , Ruggero Carli , Gianluigi Pillonetto , Luca Schenato

Astrometric accuracy of complex modern VLBI arrays cannot be calculated analytically. We study the astrometric accuracy of phase-referenced VLBI observations for the VLBA, EVN and global VLBI array by simulating VLBI data for targets at…

Astrophysics · Physics 2009-11-11 N. Pradel , P. Charlot , J. -F. Lestrade

Context. Very Long Baseline Interferometry (VLBI) data are extremely sensitive to the phase stability of the VLBI array. This is especially important when we reach {\mu}Jy r.m.s. sensitivities. Calibration using standard phase referencing…

Instrumentation and Methods for Astrophysics · Physics 2016-02-24 Jack F. Radcliffe , Michael A. Garrett , Rob J. Beswick , Tom W. B. Muxlow , Peter Barthel , Adam T. Deller , Enno Middelberg

High-precision frequency estimation is an ubiquitous issue in fundamental physics and a critical task in spectroscopy. Here, we propose a quantum Ramsey interferometry to realize high-precision frequency estimation in spin-1 Bose-Einstein…

Quantum Physics · Physics 2021-09-06 Min Zhuang , Hongtao Huo , Yuxiang Qiu , Wenjie Liu , Jiahao Huang , Chaohong Lee

The very long baseline interferometry (VLBI) technique offers angular resolutions superior to any other instruments at other wavelengths, enabling unique science applications of high-resolution imaging of radio sources and high-precision…

Instrumentation and Methods for Astrophysics · Physics 2018-02-06 T. An , B. W. Sohn , H. Imai

We present the laboratory verification of a method for re- moving the effects of frozen-flow atmospheric turbulence using a Linear Quadratic Gaussian (LQG) controller, also known as a Kalman Filter. This method, which we term "Predictive…

Instrumentation and Methods for Astrophysics · Physics 2015-04-16 Alexander Rudy , Lisa Poyneer , Srikar Srinath , S. Mark Ammons , Donald Gavel

In this study, we introduce a novel analytical Gaussian Process (GP) cosmography methodology, leveraging the differentiable properties of GPs to derive key cosmological quantities analytically. Our approach combines cosmic chronometer (CC)…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-19 Bikash R. Dinda

We present a high-precision temporal-spatial phase-demodulation algorithm for phase-shifting interferometry (PSI) affected by random/systematic phase-stepping errors. Laser interferometers in standard optical-shops suffer from several error…

Signal Processing · Electrical Eng. & Systems 2019-12-11 Manuel Servin , Moises Padilla , Guillermo Garnica , Gonzalo Paez

The East Asia VLBI Network (EAVN) has recently enabled dual-polarization observations at $22$ and $43\,\mathrm{GHz}$. We present the first systematic verification of its polarimetric performance using EAVN observations of M87, 3C 279, 3C…

Evaporation is one of the main processes in the hydrological cycle, and it is one of the most critical factors in agricultural, hydrological, and meteorological studies. Due to the interactions of multiple climatic factors, the evaporation…

The problem of phaseless aperture synthesis is of current interest in phase-unstable VLBI with a small number of elements when either the use of closure phases is not possible (a two-element interferometer) or their quality and number are…

Astrophysics · Physics 2009-11-10 Anisa T. Bajkova

We present a cost-effective method for model calibration and solution of source inversion problems in atmospheric dispersion modelling. We use Gaussian process emulations of atmospheric dispersion models within a Bayesian framework for…

Numerical Analysis · Mathematics 2021-06-08 Juan G. Garcia , Bamdad Hosseini , John M Stockie

This document describes the advantages of applying "Source/Frequency Phase Referencing" (SFPR) techniques to the analysis of VLBI observations with VSOP-2, for high precision astrometric measurements and/or increased sensitivity. The SFPR…

Instrumentation and Methods for Astrophysics · Physics 2009-10-08 Maria J. Rioja , Richard Dodson
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