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AR Scorpii (AR Sco), the only-known radio-pulsing white dwarf binary, shows unusual pulsating emission at the radio, infrared, optical and ultraviolet bands. To determine its astrometric parameters at the radio band independently, we…

We describe a method for deriving the position and flux of point and compact sources observed by a scanning survey mission. Results from data simulated to test our method are presented, which demonstrate that at least a 10-fold improvement…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 F. van Leeuwen , A. N. Morgan , D. L. Harrison

This paper demonstrates the feasibility of single-antenna and single-RF (radio frequency)- anchor received power strength indicator (RSSI) localization (SARR-LOC) with the assistance of the computer vision (CV) technique. Generally, to…

Multimedia · Computer Science 2021-12-07 Tomoya Sunami , Sohei Itahara , Yusuke Koda , Takayuki Nishio , Koji Yamamoto

We report a radio SETI search for periodic, kHz-wide signals from five of the nearest stars observable with the Five-hundred-meter Aperture Spherical radio Telescope (FAST). Using the 19-beam L-band receiver (1.05-1.45 GHz), we obtained…

Solar and Stellar Astrophysics · Physics 2026-01-22 Yu Hu , Bo-Lun Huang , Vishal Gajjar , Xiao-Hang Luan , Zhen-Zhao Tao , Tong-Jie Zhang

We consider the problem of joint three-dimensional (3D) localization and material classification of unresolved space debris using a multispectral rotating point spread function (RPSF). The use of RPSF allows one to estimate the 3D locations…

Image and Video Processing · Electrical Eng. & Systems 2020-01-08 Chao Wang , Grey Ballard , Robert Plemmons , Sudhakar Prasad

Accurate characterization of radiation pulse profiles is crucial for optimizing beam quality and enhancing experimental outcomes in Free Electron Laser (FEL) research. In this paper, we present a novel approach that employs machine learning…

Accelerator Physics · Physics 2024-11-27 Till Korten , Vladimir Rybnikov , Peter Steinbach , Najmeh Mirian

The next generation of cosmology space missions will be sensitive to parasitic signals arising from cosmic rays. Using a composite bolometer, we have investigated pulses produced by $\alpha$ particles in order to understand the movement of…

Instrumentation and Methods for Astrophysics · Physics 2018-07-26 S. L. Stever , F. Couchot , N. Coron , R. M. J. Janssen , B. Maffei

Very long baseline interferometry (VLBI) provides the resolution needed to make precision measurements of a pulsar's parallax and proper motion. In making these measurements, the astronomer is faced with difficult calibration problems and a…

Astrophysics · Physics 2007-05-23 Walter Brisken

Context. Polarimetric imaging is one of the most effective techniques for high-contrast imaging and characterization of protoplanetary disks, and has the potential to be instrumental in characterizing exoplanets. VLT/SPHERE contains the…

We develop two algorithms, based on maximum likelihood (ML) inference, for estimating the parameters of polarized radio sources which emit at a single rotation measure (RM), e.g., pulsars. These algorithms incorporate the flux density…

Instrumentation and Methods for Astrophysics · Physics 2017-10-25 D. H. F. M. Schnitzeler , K. J. Lee

This paper describes a new approach to the optimization of information extraction in multi-wavelength image cubes of cosmological fields. The objective is to create a framework for the automatic identification and tagging of sources…

Instrumentation and Methods for Astrophysics · Physics 2015-06-04 Maria Jose Marquez

We study the polarization properties of the prompt emission of gamma-ray bursts produced by fragmented fireballs. Such fireballs, known in the literature under various names, are made by the superposition of many individual blobs, each of…

High Energy Astrophysical Phenomena · Physics 2015-05-13 Davide Lazzati , Mitchell Begelman

In this paper we consider the problem of localizing a set of broadband sources from a finite window of measurements. In the case of narrowband sources this can be reduced to the problem of spectral line estimation, where our goal is simply…

Signal Processing · Electrical Eng. & Systems 2022-10-24 Coleman DeLude , Rakshith Sharma , Santhosh Karnik , Christopher Hood , Mark Davenport , Justin Romberg

We show that the pumping current is a convenient parameter for manipulating the temporal Localized Structures (LSs), also called localized pulses, found in passively mode-locked Vertical-Cavity Surface-Emitting Lasers. While short…

Optics · Physics 2017-01-04 P. Camelin , J. Javaloyes , M. Marconi , M. Giudici

We demonstrate the implementation of a fiber-integrated spectrograph utilizing chromatic group velocity dispersion (GVD) in a single mode fiber. By means of GVD we stretch an ultrafast pulse in time in order to spectrally resolve single…

Quantum Physics · Physics 2009-09-15 Malte Avenhaus , Andreas Eckstein , Peter J. Mosley , Christine Silberhorn

On 18 November 1993, we observed the QSO 1150+812 and the BL Lac object 1803+784, nearly 15\deg apart on the sky, with a VLBI array, simultaneously recording at 8.4 and 2.3 GHz. Using difference astrometry techniques, we determined the…

The study of the linear and circular polarization in AGN allows one to gain detailed information about the properties of the magnetic fields in these objects. However, especially the observation of circular polarization (CP) with…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 E. Cenacchi , A. Kraus , A. Orfei , K. -H. Mack

A new detection scheme capable of acquiring the entire spatiotemporal profile of terahertz radiation in a single laser shot is being demonstrated. The design allows temporal resolution of the order of transform-limited pulse duration of the…

Plasma Physics · Physics 2016-02-19 Sonal Saxena , B. S. Rao , J. A. Chakera , P. A. Naik

Single-photon Lidar (SPL) offers unprecedented sensitivity and time resolution, which enables Satellite Laser Ranging (SLR) systems to identify space debris from distances spanning thousands of kilometers. However, existing SPL systems face…

Data Analysis, Statistics and Probability · Physics 2024-01-10 Xialin Liu , Jia Qiang , Genghua Huang , Liang Zhang , Zheng Zhao , Rong Shu

We have carried out a high-precision astrometric analysis of two very-long-baseline-interferometry (VLBI) epochs of observation of the 13 extragalactic radio sources in the complete S5 polar cap sample. The VLBI epochs span a time baseline…

Astrophysics of Galaxies · Physics 2016-11-30 I. Marti-Vidal , F. J. Abellan , J. M. Marcaide , J. C. Guirado , M. A. Perez-Torres , E. Ros