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Related papers: Multi-frequency imaging in VLBI

200 papers

Multimode fibres (MMF) are remarkable high-capacity information channels owing to the large number of transmitting fibre modes, and have recently attracted significant renewed interest in applications such as optical communication, imaging,…

Optics · Physics 2018-08-27 Pengfei Fan , Tianrui Zhao , Lei Su

Multi-spectral quantitative phase imaging (MS-QPI) is a cutting-edge label-free technique to determine the morphological changes, refractive index variations and spectroscopic information of the specimens. The bottleneck to implement this…

Quantitative phase imaging (QPI) through multi-core fibers (MCFs) has been an emerging in vivo label-free endoscopic imaging modality with minimal invasiveness. However, the computational demands of conventional iterative phase retrieval…

Snapshot Multispectral Light-field Imaging (SMLI) is an emerging computational imaging technique that captures high-dimensional data (x, y, z, $\theta$, $\phi$, $\lambda$) in a single shot using a low-dimensional sensor. The accuracy of…

Signal Processing · Electrical Eng. & Systems 2025-09-03 Erqi Huang , John Restrepo , Xun Cao , Ivo Ihrke

Image reconstruction in very-long baseline interferometry operates under severely sparse aperture coverage with calibration challenges from both the participating instruments and propagation medium, which introduce the risk of biases and…

Instrumentation and Methods for Astrophysics · Physics 2026-01-14 Samuel Lai , Nithyanandan Thyagarajan , O. Ivy Wong , Foivos Diakogiannis

Purpose: Different Magnetic resonance imaging (MRI) modalities of the same anatomical structure are required to present different pathological information from the physical level for diagnostic needs. However, it is often difficult to…

Image and Video Processing · Electrical Eng. & Systems 2021-09-15 Yuchen Fei , Bo Zhan , Mei Hong , Xi Wu , Jiliu Zhou , Yan Wang

We propose neural network layers that explicitly combine frequency and image feature representations and show that they can be used as a versatile building block for reconstruction from frequency space data. Our work is motivated by the…

Computer Vision and Pattern Recognition · Computer Science 2023-06-29 Nalini M. Singh , Juan Eugenio Iglesias , Elfar Adalsteinsson , Adrian V. Dalca , Polina Golland

We describe a new method which achieves high precision Very Long Baseline Interferometry (VLBI) astrometry in observations at millimeter wavelengths. It combines fast frequency-switching observations, to correct for the dominant…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 Maria J. Rioja , Richard Dodson

Accurate extraction of multicomponent linear frequency modulation (LFM) signal parameters, such as onset frequency, linear modulation frequency, amplitude, and initial phase, is of great importance in the fields of ISAR, cognitive radio,…

Information Theory · Computer Science 2024-12-06 Huigaung Zhang

Connected radio interferometers are sometimes used in the tied-array mode: signals from antenna elements are coherently added and the sum signal applied to a VLBI backend or pulsar processing machine. Usually there is no computer-controlled…

Instrumentation and Methods for Astrophysics · Physics 2010-11-09 P. A. Fridman

Infrared and Visible Image Fusion (IVIF) has shown promise in visual tasks under challenging environments, but fusion under unregistered conditions faces inherent misalignments. Current studies to solve them either predict the deformation…

Computer Vision and Pattern Recognition · Computer Science 2026-05-14 Xingyuan Li , Haoyuan Xu , Xingyue Zhu , Jun Ma , Yang Zou , Zhiying Jiang , Jinyuan Liu

Advancements in high-throughput biomedical applications require real-time, large field-of-view (FOV) imaging. While current 2D lens-free imaging (LFI) systems improve FOV, they are often hindered by time-consuming multi-position…

Radio frequency interference (RFI) is the principal factor limiting the sensitivities of radio telescopes, particularly at frequencies below 1 GHz. I present a conceptually new approach to mitigation of RFI in interferometric data. This has…

Instrumentation and Methods for Astrophysics · Physics 2011-02-11 Ramana Athreya

Over the past several decades, many different types of computational imaging approaches have been proposed for improving MRI. In this paper, we provide an overview of methods that assume that MRI Fourier data is linearly predictable. Linear…

Signal Processing · Electrical Eng. & Systems 2020-02-19 Justin P. Haldar , Kawin Setsompop

While conventional imaging in VLBI provides information only about the relative position between different features of a given source, phase-referenced observations can provide precise positional information with respect to an external…

Astrophysics · Physics 2007-05-23 Eduardo Ros

VLTi Spectro-Imager (VSI) is a proposition for a second generation VLTI instrument which is aimed at providing the ESO community with the capability of performing image synthesis at milli-arcsecond angular resolution. VSI provides the VLTI…

We discuss a technique for mapping the synchrotron turnover frequency distribution using nearly simultaneous, multi--frequency VLBI observations. The limitations of the technique arising from limited spatial sampling and frequency coverage…

Astrophysics · Physics 2009-10-30 A. P. Lobanov

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…

Instrumentation and Methods for Astrophysics · Physics 2025-11-25 Paul Tiede , William Moses , Valentin Churavy , Michael D. Johnson , Dominic Pesce , Lindy Blackburn , Peter Galison

Magnetic Resonance Fingerprinting (MRF) is an emerging technology with the potential to revolutionize radiology and medical diagnostics. In comparison to traditional magnetic resonance imaging (MRI), MRF enables the rapid, simultaneous,…

Multi-Modal Image Fusion (MMIF) aims to combine images from different modalities to produce fused images, retaining texture details and preserving significant information. Recently, some MMIF methods incorporate frequency domain information…

Computer Vision and Pattern Recognition · Computer Science 2026-02-05 Yixin Zhu , Long Lv , Pingping Zhang , Xuehu Liu , Tongdan Tang , Feng Tian , Weibing Sun , Huchuan Lu