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相关论文: Identifying synergies between VLBI and STIX imagin…

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Very long baseline interferometry (VLBI) achieves the highest angular resolution in astronomy. VLBI measures corrupted Fourier components, known as visibilities. Reconstructing on-sky images from these visibilities is a challenging inverse…

天体物理仪器与方法 · 物理学 2025-11-25 Paul Tiede , William Moses , Valentin Churavy , Michael D. Johnson , Dominic Pesce , Lindy Blackburn , Peter Galison

Very long baseline interferometry (VLBI) is a technique for imaging celestial radio emissions by simultaneously observing a source from telescopes distributed across Earth. The challenges in reconstructing images from fine angular…

天体物理仪器与方法 · 物理学 2016-11-08 Katherine L. Bouman , Michael D. Johnson , Daniel Zoran , Vincent L. Fish , Sheperd S. Doeleman , William T. Freeman

Self-calibration methods with the CLEAN algorithm have been widely employed in Very Long Baseline Interferometry (VLBI) data processing in order to correct antenna-based amplitude and phase corruptions present in the data. However, human…

Aims: To provide the first demonstration of STIX Fourier-transform X-ray imaging using semi-calibrated (amplitude-only) visibility data acquired during the Solar Orbiter's cruise phase. Methods: We use a parametric imaging approach by which…

Very long baseline interferometry (VLBI) is a radio-astronomical technique in which the correlated signal from various baselines is combined into an image of highest angular resolution. Due to sparsity of the measurements, this imaging…

天体物理仪器与方法 · 物理学 2023-03-29 Hendrik Müller , Andrei Lobanov

Space telescopes for solar hard X-ray imaging provide observations made of sampled Fourier components of the incoming photon flux. The aim of this study is to design an image reconstruction method relying on enhanced visibility…

天体物理仪器与方法 · 物理学 2021-10-13 Emma Perracchione , Paolo Massa , Anna Maria Massone , Michele Piana

For Very Long Baseline Interferometry (VLBI), the fringe spacing is extremely narrow compared to the field of view imposed by the primary beam of each element. This means that an extremely large number of resolution units can potentially be…

天体物理仪器与方法 · 物理学 2013-02-26 John S. Morgan , F. Mantovani , A. T. Deller , W. Brisken , W. Alef , E. Middelberg , M. Nanni , S. J. Tingay

Reconstructing images from very long baseline interferometry (VLBI) data with sparse sampling of the Fourier domain (uv-coverage) constitutes an ill-posed deconvolution problem. It requires application of robust algorithms maximizing the…

天体物理仪器与方法 · 物理学 2022-10-19 Hendrik Müller , Andrei Lobanov

In very long baseline interferometry (VLBI) the combination of multiple antennas permits the synthesis of a virtual telescope with a larger diameter and consequently higher resolution than the individual antennae. Yet, due to the sparse…

天体物理仪器与方法 · 物理学 2024-08-14 Alejandro Mus , Hendrik Müller , Andrei Lobanov

Extracting polarimetric information from very long baseline interferometry (VLBI) data is demanding but vital for understanding the synchrotron radiation process and the magnetic fields of celestial objects, such as active galactic nuclei…

Very-long-baseline interferometry (VLBI) is a challenging observational technique, which requires in-depth knowledge about radio telescope instrumentation, interferometry, and the handling of noisy data. The reduction of the raw data is…

天体物理仪器与方法 · 物理学 2022-09-14 Michael Janssen , Jack F. Radcliffe , Jan Wagner

The VLTI Spectro Imager (VSI) was proposed as a second-generation instrument of the Very Large Telescope Interferometer providing the ESO community with spectrally-resolved, near-infrared images at angular resolutions down to 1.1…

Very long baseline interferometry (VLBI) makes it possible to recover images of astronomical sources with extremely high angular resolution. Most recently, the Event Horizon Telescope (EHT) has extended VLBI to short millimeter wavelengths…

Aima. To determine to what extent the problem of forward fitting visibilities measured by the Spectrometer/Telescope Imaging X-rays (STIX) on-board Solar Orbiter is more challenging with respect to the same problem in the case of previous…

Just as turbulence in the Earth's atmosphere can severely limit the angular resolution of optical telescopes, turbulence in the ionized interstellar medium fundamentally limits the resolution of radio telescopes. We present a scattering…

天体物理仪器与方法 · 物理学 2016-12-14 Michael D. Johnson

Context. The Spectrometer/Telescope for Imaging X-rays (STIX) is one of 6 remote sensing instruments on-board Solar Orbiter. It provides hard X-ray imaging spectroscopy of solar flares by sampling the Fourier transform of the incoming flux.…

By linking widely separated radio dishes, the technique of very long baseline interferometry (VLBI) can greatly enhance angular resolution in radio astronomy. However, at any given moment, a VLBI array only sparsely samples the information…

Very Long Baseline Interferometry (VLBI) provides the finest angular resolution of all astronomical observation techniques. However, observations with Earth-based instruments are approaching fundamental limits on angular resolution. These…

天体物理仪器与方法 · 物理学 2025-04-14 Ben Hudson , Leonid I. Gurvits , Daniel Palumbo , Sara Issaoun , Hannah Rana

Recent developments in very long baseline interferometry (VLBI) have made it possible for the Event Horizon Telescope (EHT) to resolve the innermost accretion flows of the largest supermassive black holes on the sky. The sparse nature of…

For many practical applications in wireless communications, we need to recover a structured sparse signal from a linear observation model with dynamic grid parameters in the sensing matrix. Conventional expectation maximization (EM)-based…

信号处理 · 电气工程与系统科学 2023-11-14 Wenkang Xu , An Liu , Bingpeng Zhou , Minjian Zhao
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