English
Related papers

Related papers: Observations of 2D Doppler backscattering on MAST

200 papers

Doppler Imaging (DI) is a well-established technique to map a physical field at a stellar surface from a time series of high-resolution spectra. In this proof-of-concept study, we aim to show that traditional DI algorithms, originally…

The Five-hundred-meter Aperture Spherical Telescope (FAST), the world's largest single-dish radio telescope, lists the search for extraterrestrial intelligence (SETI) as one of its key scientific objectives. In this work, we present a…

Instrumentation and Methods for Astrophysics · Physics 2026-01-19 Jian-Kang Li , Zhen-Zhao Tao , Pei Wang , Tong-Jie Zhang

Doppler-free spectroscopy using two counter-propagating dual-frequency laser beams in alkali vapor cells has been demonstrated recently, providing the detection of high-contrast sign-reversed natural-linewidth sub-Doppler resonances.…

Radially self-accelerating light exhibits an intensity pattern that describes a spiraling trajectory around the optical axis as the beam propagates. In this article, we show in simulation and experiment how such beams can be used to perform…

Optics · Physics 2021-04-08 Shashi Prabhakar , Stephen Plachta , Marco Ornigotti , Robert Fickler

There has been extensive activity exploring the doping of semiconducting two-dimensional (2D) transition metal dichalcogenides in order to tune their electronic and magnetic properties. The outcome of doping depends on various factors,…

Precession of a converged beam during acquisition of a 4D-STEM dataset improves strain, orientation, and phase mapping accuracy by averaging over continuous angles of illumination. Precession experiments usually rely on integrated systems,…

Instrumentation and Detectors · Physics 2025-10-20 Stephanie M. Ribet , Rohan Dhall , Colin Ophus , Karen C. Bustillo

We present a methodology for the regularisation and combination of sparse sampled and irregularly gridded observations from fibre-optic multi-object integral-field spectroscopy. The approach minimises interpolation and retains image…

We present methods for analyzing Beam Emission Spectroscopy (BES) data to obtain the plasma density evolution associated with rapid sawtooth crash events at the DIII-D tokamak. BES allows coverage over a 2-D spatial plane, inherently local…

Plasma Physics · Physics 2022-10-12 Sayak Bose , William Fox , Dingyun Liu , Zheng Yan , George McKee , Aaron Goodman , Hantao Ji

We present monostatic sampling methods for limited-aperture scattering problems in two dimensions. The direct sampling method (DSM) is well known to provide a robust, stable, and fast numerical scheme for imaging inhomogeneities from…

Numerical Analysis · Mathematics 2022-04-14 Sangwoo Kang , Mikyoung Lim

This paper proposes a wideband dual-polarized phased array with ultra-wideband scattering cross section (SCS) reduction. The antenna elements are loaded on a bilateral stepped ground. This ground is carefully designed in terms of height…

Optics · Physics 2025-10-20 Yu Luo , Shi-Gang Fang , Peng-Fa Li , Yuhao Feng , Shi-Wei Qu , Shiwen Yang

An FPGA based digital signal processing (DSP) system for biasing and reading out multiplexed bolometric detectors for mm-wavelength telescopes is presented. This readout system is being deployed for balloon-borne and ground based cosmology…

Instrumentation and Detectors · Physics 2009-05-13 Matt Dobbs , Eric Bissonnette , Helmuth Spieler

Simultaneous localization and mapping (SLAM) is a critical capability for autonomous systems. Traditional SLAM approaches, which often rely on visual or LiDAR sensors, face significant challenges in adverse conditions such as low light or…

Robotics · Computer Science 2026-02-06 Dong Wang , Hannes Haag , Daniel Casado Herraez , Stefan May , Cyrill Stachniss , Andreas Nüchter

Distinguishing signal of young gas rich circumstellar disks from stellar signal in near infrared light is a difficult task. Current techniques such as Angular Differential Imaging (ADI) and Polarimetric Differential Imaging (PDI) cope with…

Instrumentation and Methods for Astrophysics · Physics 2022-12-07 L. M. Stapper , C. Ginski

The recently introduced non-iterative imaging method entitled \enquote{direct sampling method} (DSM) is known to be fast, robust, and effective for inverse scattering problems in the multi-static configuration but fails when applied to the…

Numerical Analysis · Mathematics 2019-04-30 Sangwoo Kang , Marc Lambert , Won-Kwang Park

Differential dynamic microscopy (DDM) is a digital video-microscopy technique for quantitative measurements of the microscale dynamics in soft condensed matter systems. Here, multi-tau pulsed illumination DDM (MTPI-DDM) is introduced as a…

Soft Condensed Matter · Physics 2026-05-19 Emmanuel Schaub , Martinus H. V. Werts

A theoretical analysis for the stimulated Raman scattering (SRS) instability driven by two laser beams with certain frequency difference is presented. It is found that strong coupling and enhanced SRS take place only when the unstable…

Plasma Physics · Physics 2022-03-25 Yao Zhao , Suming Weng , Min Chen , Jun Zheng , Hongbin Zhuo , Chuang Ren , Zhengming Sheng , Jie Zhang

Scanning transmission electron microscopy (STEM) is the most widespread adopted tool for atomic scale characterization of two-dimensional (2D) materials. Many 2D materials remain susceptible to electron beam damage, despite the standardized…

Materials Science · Physics 2021-08-11 Sytze de Graaf , Majid Ahmadi , Ivan Lazić , Eric G. T. Bosch , Bart J. Kooi

Due to its particular geometry, stimulated Raman side-scattering (SRSS) drives scattered light emission at non-conventional directions, leading to scarce and complex experimental observations. Direct-irradiation campaigns at the SG-II UP…

In this article, we address the timely topic of cellular bistatic simultaneous localization and mapping (SLAM) with specific focus on end-to-end processing solutions, from raw I/Q samples, via channel parameter estimation to user equipment…

Signal Processing · Electrical Eng. & Systems 2024-05-21 Elizaveta Rastorgueva-Foi , Ossi Kaltiokallio , Yu Ge , Matias Turunen , Jukka Talvitie , Bo Tan , Musa Furkan Keskin , Henk Wymeersch , Mikko Valkama

Digital two-dimensional (2D) spatial sampling devices (such as charge-coupled device) have been widely used in various imaging systems, especially in computational imaging systems. However, the undersampling of digital sampling devices is a…

Image and Video Processing · Electrical Eng. & Systems 2019-10-02 Junzheng Peng , Manhong Yao , Zixin Cai , Xue Qiu , Zibang Zhang , Shiping Li , Jingang Zhong