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A simultaneously transmitting and reflecting surface (STARS) assisted near-field (NF) integrated sensing and communication (ISAC) framework is proposed, where the radio sensors are installed on the STARS to directly conduct the…

Signal Processing · Electrical Eng. & Systems 2025-06-03 Na Xue , Xidong Mu , Yue Chen , Yuanwei Liu

A new method, FM-FTS, combining Frequency Modulation heterodyne laser spectroscopy and Fourier Transform Spectroscopy is presented. It provides simultaneous sensitive measurement of absorption and dispersion profiles with broadband spectral…

Optics · Physics 2007-09-24 Julien Mandon , Guy Guelachvili , Nathalie Picqué

In this paper, a learning-based approach is proposed for optimizing downlink beamforming in multiple-input multiple-output (MIMO) systems that employ continuous aperture arrays (CAPAs) at both the base station (BS) and the user. Beamforming…

Signal Processing · Electrical Eng. & Systems 2026-03-18 Shiyong Chen , Jia Guo , Shengqian Han

Powered by position-flexible antennas, the emerging fluid antenna system (FAS) technology is postulated as a key enabler for massive connectivity in 6G networks. The free movement of antenna elements enables the opportunistic minimization…

Signal Processing · Electrical Eng. & Systems 2024-07-24 Pablo Ramirez-Espinosa , David Morales-Jimenez , Kai-Kit Wong

We design a two-dimensional signal constellation based on the exact periodic inverse nonlinear Fourier transform. Feasibility of continuous transmission with periodic signals is experimentally demonstrated over more than 2000 km.

Information Theory · Computer Science 2019-04-30 Jan-Willem Goossens , Yves Jaouën , Hartmut Hafermann

Transient detection and flux measurement via image subtraction stand at the base of time domain astronomy. Due to the varying seeing conditions, the image subtraction process is non-trivial, and existing solutions suffer from a variety of…

Instrumentation and Methods for Astrophysics · Physics 2016-10-12 Barak Zackay , Eran O. Ofek , Avishay Gal-Yam

In this paper, we study efficient beam coverage design for multi-antenna systems in both far-field and near-field cases. To reduce the computational complexity of existing sampling-based optimization methods, we propose a new low-complexity…

Information Theory · Computer Science 2026-02-06 Chao Zhou , Changsheng You , Cong Zhou , Li Chen , Yi Gong , Chengwen Xing

In the case of vector flow imaging systems, the most employed flow estimation techniques are the directional beamforming based cross correlation and the triangulation-based autocorrelation. However, the directional beamforming-based…

Signal Processing · Electrical Eng. & Systems 2022-06-07 A. N. Madhavanunni , Mahesh Raveendranatha Panicker

Calculations of the Fourier transform of a constant quantity over an area or volume defined by polygons (connected vertices) are often useful in modeling wave scattering, or in fourier-space filtering of real-space vector-based volumes and…

Numerical Analysis · Mathematics 2021-04-20 Brian B. Maranville

Current and upcoming radio-interferometers are expected to produce volumes of data of increasing size that need to be processed in order to generate the corresponding sky brightness distributions through imaging. This represents an…

Instrumentation and Methods for Astrophysics · Physics 2023-01-18 Claudio Gheller , Giuliano Taffoni , David Goz

Though Fourier Transforms (FTs) are a common technique for finding correlation functions, they are not typically used in computations of the anisotropy of the two-point correlation function (2PCF) about the line of sight in wide-angle…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-28 Zachary Slepian , Daniel J. Eisenstein

We consider imaging of fast moving small objects in space, such as low earth orbit satellites, which are also rotating around a fixed axis. The imaging system consists of ground based, asynchronous sources of radiation and several passive…

Signal Processing · Electrical Eng. & Systems 2021-11-03 Matan Leibovich , George Papanicolaou , Chrysoula Tsogka

NIR-II fluorescence imaging provides superior tissue penetration and clarity, yet its clinical use in surgical navigation is hindered by a critical workflow issue. Surgeons must divert their attention between the operative field and…

This paper presents a physics-consistent framework for bistatic sensing incorporating a 2-Dimensional (2D) waveguide-fed metasurface antenna array capable of realizing eXtremely-Large Multiple-Input Multiple-Output (XL MIMO) apertures. A…

Signal Processing · Electrical Eng. & Systems 2025-11-13 Ioannis Gavras , Panagiotis Gavriilidis , George C. Alexandropoulos

Wide-field (> 100 deg$^2$) hard X-ray coded-aperture telescopes with high angular resolution (< 2') will enable a wide range of time domain astrophysics. For instance, transient sources such as gamma-ray bursts can be precisely localized…

Instrumentation and Methods for Astrophysics · Physics 2016-12-28 Jaesub Hong , Branden Allen , Jonathan Grindlay , Scott Barthelmy

The Fourier inversion of phased coherent diffraction patterns offers images without the resolution and depth-of-focus limitations of lens-based tomographic systems. We report on our recent experimental images inverted using recent…

RISTRETTO is the evolution of the original idea of coupling the VLT instruments SPHERE and ESPRESSO \cite{lovis_2016a}, aiming at High Dispersion Coronagraphy. RISTRETTO is a visitor instrument that should enable the characterization of the…

Instrumentation and Methods for Astrophysics · Physics 2024-09-13 N. Blind , M. Shinde , I. Dinis , N. Restori , B. Chazelas , T. Fusco , O. Guyon , J. Kuehn , C. Lovis , P. Martinez , M. Motte , J. -F. Sauvage , A. Spang

Ultrahigh-field MRI, such as those operating at 7 Tesla, enhances diagnostic capabilities but also presents unique challenges, including the need for advanced RF coil designs to achieve an optimal signal-to-noise ratio and transmit…

Medical Physics · Physics 2025-02-11 Yunkun Zhao , Komlan Payne , Leslie Ying , Xiaoliang Zhang

Stellar intensity interferometry (SII) is based on the correlation of the light intensity fluctuations of a star detected at two or more telescopes, with no need to combine the collected photons directly. A measurement of the correlation in…

Instrumentation and Methods for Astrophysics · Physics 2024-04-30 Alessia Spolon , Michele Fiori , Luca Zampieri , Marco Landoni

Beamforming is central to the processing function of all phased arrays and becomes particularly challenging with a large number of antenna element (e.g. >100,000). The ability to beamform efficiently with reasonable power requirements is…

Instrumentation and Methods for Astrophysics · Physics 2010-08-25 A J Faulkner , K Zarb Adami , J. G. Bij de Vaate , G. W. Kant , P. Pickard