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Related papers: Observations of 2D Doppler backscattering on MAST

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Distributed acoustic sensing (DAS) is a relatively new technology for recording stress wave propagation, with promising applications in both engineering and geophysics. DAS's ability to simultaneously collect high spatial resolution data…

Geophysics · Physics 2022-10-27 Michael B. S. Yust , Brady R. Cox , Joseph P. Vantassel , Peter G. Hubbard

We introduce the sparse direct sampling method (DSM) to estimate properties of a region from signals that probe the region. We demonstrate the sparse-DSM on two separate problems: estimating both the angle-of-arrival of a radio wave…

Analysis of PDEs · Mathematics 2020-10-19 Isaac Harris , Jacob D Rezac

The direct sampling method (DSM) has been introduced for non-iterative imaging of small inhomogeneities and is known to be fast, robust, and effective for inverse scattering problems. However, to the best of our knowledge, a full analysis…

Numerical Analysis · Mathematics 2018-09-26 Sangwoo Kang , Marc Lambert , Won-Kwang Park

Many emerging reconfigurable optical systems are limited by routing complexity when producing dynamic, two-dimensional (2D) electric fields. Using a gradient-based inverse designed, static phase-mask doublet, we propose an optical system to…

A multichannel dual-comb spectroscopy (DCS) approach for high-resolution, broadband spectral measurements is presented, demonstrating its effectiveness in studying complex atomic systems. By implementing a photodetector array, we enhance…

Atomic Physics · Physics 2025-03-14 R. Aramyan , O. Tretiak , S. S. Sahoo , D. Budker

We study modulation spectroscopy of the potassium D2 transitions at 766.7 nm. The vapour pressure, controlled by heating a commercial reference cell, is optimized using conventional saturated absorption spectroscopy. Subsequent heterodyne…

Atomic Physics · Physics 2012-05-03 L. Mudarikwa , K. Pahwa , J. Goldwin

We describe an experiment to measure the polarization of the Cosmic Microwave Background (CMB) with the Degree Angular Scale Interferometer (DASI), a compact microwave interferometer optimized to detect CMB anisotropy at multipoles 140 to…

We study the existence and suppression of artifacts for a Doppler-based Synthetic Aperture Radar (DSAR) system. The idealized air- or space-borne system transmits a continuous wave at a fixed frequency and a co-located receiver measures the…

Analysis of PDEs · Mathematics 2024-02-20 Raluca Felea , Romina Gaburro , Allan Greenleaf , Clifford Nolan

A phase retrieval technique using a spatial light modulator (SLM) and a phase diffuser for a fast reconstruction of smooth wave fronts is demonstrated experimentally. Diffuse illumination of a smooth test object with the aid of a phase…

Optics · Physics 2015-06-11 Mostafa Agour , Percival F. Almoro , Claas Falldorf

The Beam Emission Spectroscopy (BES) turbulence diagnostic on MAST is to be upgraded in June 2010 from a 1D trial system to a 2D imaging system (8 radial \times 4 poloidal channels) based on a newly developed APD array camera. The spatial…

Plasma Physics · Physics 2012-03-26 Y. -c. Ghim , A. R. Field , S. Zoletnik , D. Dunai

Conformal phased arrays promise shape-changing properties, multiple degrees of freedom to the scan angle, and novel applications in wearables, aerospace, defense, vehicles, and ships. However, they have suffered from two critical…

Conventional silicon photomultipliers (SiPMs) are well established as light detectors with single-photon-detection capability and used throughout high energy physics, medical, and commercial applications. The possibility to produce single…

Today, wide-open, high-resolution Doppler frequency shift (DFS) estimation is essential for radar, microwave/millimeter-wave, and communication systems. Using photonics technology, an effective approach is proposed and experimentally…

Optics · Physics 2014-04-09 Xihua Zou , Wangzhe Li , Bing Lu , Wei Pan , Lianshan Yan , Liyang Shao

Plastic scintillation detectors are increasingly used to measure dose distributions in the context of radiotherapy treatments. Their water-equivalence, real-time response and high spatial resolution distinguish them from traditional…

Medical Physics · Physics 2021-09-22 Emily Cloutier , Louis Archambault , Luc Beaulieu

Conformal phased arrays promise shape-changing properties, multiple degrees of freedom to the scan angle, and novel applications in wearables, aerospace, defense, vehicles, and ships. However, they have suffered from two critical…

We report the observation of two additional sub-natural line width quantum interference in the $D_2$ manifold of $^{39}K$ vapor, in addition to the usual single Electromagnetically induced transparency peak. The other two features appear…

Atomic Physics · Physics 2024-03-28 Gourab Pal , Subhasish Dutta Gupta , Saptarishi Chaudhuri

We demonstrate a multi-beam scanning transmission electron microscopy (STEM) imaging that integrates down-sampling with super-resolution image reconstruction via a compressive sensing framework. A custom condenser aperture with six randomly…

Instrumentation and Detectors · Physics 2026-03-19 Akira Yasuhara , Takumi Sannomiya , Ryoichi Horisaki

Photoacoustic imaging (PAI) is an emerging biomedical imaging modality capable of providing both high contrast and high resolution of optical and UltraSound (US) imaging. When a short duration laser pulse illuminates the tissue as a target…

Signal Processing · Electrical Eng. & Systems 2018-01-19 Moein Mozaffarzadeh , Ali Mahloojifar , Mahdi Orooji

Observations of enhanced Doppler frequency shift effect of the highly localized microwave backscattering in the upper hybrid resonance are reported. The experiment is performed at FT-2 tokamak, where a steerable focusing antenna set,…

In Photoacoustic imaging (PA), Delay-and-Sum (DAS) beamformer is a common beamforming algorithm having a simple implementation. However, it results in a poor resolution and high sidelobes. To address these challenges, a new algorithm namely…

Signal Processing · Electrical Eng. & Systems 2018-02-13 Moein Mozaffarzadeh , Ali Mahloojifar , Mahdi Orooji , Karl Kratkiewicz , Saba Adabi , Mohammadreza Nasiriavanaki