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Related papers: Bigradient Phase Referencing

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Detecting neutral Hydrogen (H\,{\sc i}) via the 21~cm line emission from the intergalactic medium at $z\gtrsim 6$ has been identified as one of the most promising probes of the epoch of cosmic reionization -- a major phase transition of the…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-04 Nithyanandan Thyagarajan , Chris Carilli , Bojan Nikolic

Aims: MASCARA and bRing are photometric surveys designed to detect variability caused by exoplanets in stars with $m_V < 8.4$. Such variability signals are typically small and require an accurate calibration algorithm, tailored to the…

Radar sensing will be integrated into the 6G communication system to support various applications. In this integrated sensing and communication system, a radar target may also be a communication channel scatterer. In this case, the radar…

Information Theory · Computer Science 2022-02-08 Zhe Huang , Kexuan Wang , An Liu , Yunlong Cai , Rui Du , Tony Xiao Han

Phase retrieval(PR) problem is a kind of ill-condition inverse problem which is arising in various of applications. Based on the Wirtinger flow(WF) method, a reweighted Wirtinger flow(RWF) method is proposed to deal with PR problem. RWF…

Information Theory · Computer Science 2017-04-05 Ziyang Yuan , Hongxia Wang

We present a detailed multi-epoch analysis of 31 potential southern hemisphere radio calibrators that were originally observed as part of a program to maintain the International Celestial Reference Frame (ICRF). At radio wavelengths, the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 F. Hungwe , R. Ojha , R. S. Booth , M. F. Bietenholz , A. Collioud , P. Charlot , D. Boboltz , A. L. Fey

A new method for joint ranging and Phase Offset (PO) estimation of multiple drones/aircrafts is proposed in this paper. The proposed method employs the superimposed uncoordinated Automatic Dependent Surveillance Broadcast (ADS-B) packets…

Systems and Control · Electrical Eng. & Systems 2024-03-26 Mostafa Mohammadkarimi , Geert Leus , Raj Thilak Rajan

Calibration is an essential step in radio interferometric data processing that corrects the data for systematic errors and in addition, subtracts bright foreground interference to reveal weak signals hidden in the residual. These weak and…

Instrumentation and Methods for Astrophysics · Physics 2019-05-08 Sarod Yatawatta

Target detection and recognition is a very challenging task in a wireless environment where a multitude of objects are located, whether to effectively determine their positions or to identify them and predict their moves. In this work, we…

Signal Processing · Electrical Eng. & Systems 2023-05-10 Mamady Delamou , Ahmad Bazzi , Marwa Chafii , El Mehdi Amhoud

Atmospheric propagation effects at millimeter wavelengths can significantly alter the phases of radio signals and reduce the coherence time, putting tight constraints on high frequency Very Long Baseline Interferometry (VLBI) observations.…

Phase retrieval consists in the recovery of an unknown signal from phaseless measurements of its usually complex-valued Fourier transform. Without further assumptions, this problem is notorious to be severe ill posed such that the recovery…

Information Theory · Computer Science 2023-01-19 Robert Beinert , Saghar Rezaei

This paper presents a robust beam alignment technique for millimeter-wave communications in low signal-to-noise ratio (SNR) environments. The core strategy of our technique is to repeatedly transmit the most probable beam candidates to…

Information Theory · Computer Science 2023-12-05 Jihun Park , Yongjeong Oh , Jaewon Yun , Seonjung Kim , Yo-Seb Jeon

Ground-based long baseline interferometers have long been limited in sensitivity by the short integration periods imposed by atmospheric turbulence. The first observation fainter than this limit was performed on January 22, 2011 when the…

Recent developments in Phased Array direct positioning methods have improved accuracy for passively geo-locating multiple radio frequency-emitting signal sources. However, the number of geo-localisable signal sources is still limited by the…

Signal Processing · Electrical Eng. & Systems 2018-09-13 Joon Wayn Cheong , Andrew G Dempster

Phased array feeds (PAFs) for reflector antennas offer the potential for increased reflector field of view and faster survey speeds. To address some of the development challenges that remain for scientifically useful PAFs, including…

Instrumentation and Methods for Astrophysics · Physics 2015-05-14 Jonathan Landon , Michael Elmer , Jacob Waldron , David Jones , Alan Stemmons , Brian D. Jeffs , Karl F. Warnick , J. Richard Fisher , Roger D. Norrod

Spectroastrometry measures source astrometry as a function of wavelength/velocity. Reverberations of spectroastrometric signals naturally arise in broad-line regions (BLRs) of active galactic nuclei (AGNs) as a result of the continuum…

Astrophysics of Galaxies · Physics 2023-01-31 Yan-Rong Li , Jian-Min Wang

The KVN(Korean VLBI Network)-style simultaneous multi-frequency receiving mode is demonstrated to be promising for mm-VLBI observations. Recently, other Very long baseline interferometry (VLBI) facilities all over the globe start to…

Fast radio bursts (FRBs) are luminous, dispersed pulses of extra-galactic origin. The physics of the emission mechanism, the progenitor environment, and their origin are unclear. Some repeating FRBs are observed to have frequency-dependent…

Fast Radio Bursts (FRBs) are millisecond dispersed radio pulses of predominately extra-galactic origin. Although originally discovered at GHz frequencies, most FRBs have been detected between 400 to 800 MHz. Nevertheless, only a handful of…

Instrumentation and Methods for Astrophysics · Physics 2024-05-24 M. Sokolowski , G. Aniruddha , C. Di Pietrantonio , C. Harris , D. C. Price , S. McSweeney , R. B. Wayth , N. D. R. Bhat

Based on our observations of infrared targets, serious scale variation along within sequence frames has high-frequently occurred. In this paper, we propose a dynamic re-parameterization network (DRPN) to deal with the scale variation and…

Computer Vision and Pattern Recognition · Computer Science 2022-12-01 Jingchao Peng , Haitao Zhao , Zhengwei Hu , Kaijie Zhao , Zhongze Wang

We present results from pulsar observations using the Giant Metrewave Radio Telescope (GMRT) as a phased array with infield phasing. The antennas were kept in phase throughout the observation by applying antenna based phase corrections…

Instrumentation and Methods for Astrophysics · Physics 2017-07-26 Sanjay Kudale , Jayaram Chengalur