English
Related papers

Related papers: In-field phasing at the upgraded GMRT

200 papers

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.…

Using the international ground-based network of two-frequency receivers of the GPS navigation system provides a means of carrying out a global, continuous and fully-computerized monitoring of phase fluctuations of signals from…

Geophysics · Physics 2007-05-23 E. L. Afraimovich , V. A. Karachenschev

Context. We have investigated the multiwavelength emission of PSR J2021+4026, the only isolated gamma-ray pulsar known to be variable, which in October 2011 underwent a simultaneous change in gamma-ray flux and spin-down rate, followed by a…

High Energy Astrophysical Phenomena · Physics 2023-08-16 M. Razzano , A. Fiori , P. M. Saz Parkinson , R. P. Mignani , A. De Luca , A. K. Harding , M. Kerr , M. Marelli , V. Testa

The gravitational wave GW170817 from a binary neutron star merger and the simultaneous electromagnetic detection of the GRB170817A by Fermi Gamma-Ray Space Telescope, opened a new era in the multi-messenger astronomy. Furthermore, the GRBs…

High Energy Astrophysical Phenomena · Physics 2024-07-16 Alessandro Drago , Simone Bini , Mariangela Cestelli Guidi , Augusto Marcelli , Valerio Bocci , Emanuele Pace

Context: Low-frequency radio observations are heavily impacted by the ionosphere, where dispersive delays can outpace even instrumental clock offsets, posing a serious calibration challenge. Especially below 100 MHz, phase unwrapping…

Instrumentation and Methods for Astrophysics · Physics 2025-10-03 C. M. Cordun , M. A. Brentjens , H. K. Vedantham , M. Mevius

Enhanced Raman scattering can be obtained by injecting a seeded light field which is correlated with the initially prepared collective atomic excitation. This Raman amplification process can be used to realize atom-light hybrid…

Quantum Physics · Physics 2016-08-24 Zhao-Dan Chen , Chun-Hua Yuan , Hong-Mei Ma , Dong Li , L. Q. Chen , Z. Y. Ou , Weiping Zhang

We discovered four millisecond pulsars (MSPs) in searches of 80 $\gamma$-ray sources conducted from 2015 to 2017 with the Murriyang radio telescope of the Parkes Observatory. We provide an overview of the survey and focus on the results of…

Probing magnetic fields in astrophysical environments is both important and challenging. The Gradient Technique (GT) is a new tool for tracing magnetic fields, rooted in the properties of magnetohydrodynamic (MHD) turbulence and turbulent…

Astrophysics of Galaxies · Physics 2024-06-18 Yue Hu , Alex Lazarian

Gravitational waves (GWs) can resonate with magnetic fields through the Gertsenshtein-Zeldovich effect, producing electromagnetic signals at the same frequency. In pulsar magnetospheres, this conversion may yield a faint radio-band signal…

General Relativity and Quantum Cosmology · Physics 2026-05-22 Wei Hong , Peng He , Tong-Jie Zhang , Shi-Yu Li , Pei Wang

In this paper, we describe the principle of a multi-aperture interferometer that uses a phase-shifting technique and is suitable for quick, snapshot imaging of astrophysical objects at extreme angular resolution through Fourier inversion. A…

Optics · Physics 2015-05-28 Francois Henault

Interferometric observations of the low-frequency radio sky (< 1 GHz) are largely limited by systematic effects introduced by the ionosphere. Here, we analyse a ten-hour nighttime uGMRT Band-4 observation of 3C48 to characterise ionospheric…

Space Physics · Physics 2026-04-14 Dipanjan Banerjee , Abhik Ghosh , Sushanta K. Mondal , Parimal Ghosh

Extending geodetic and astrometric Very Long Baseline Interferometry (VLBI) observations from traditional centimeter wavebands to millimeter wavebands offers numerous scientific potentials and benefits. However, it was considered quite…

Pinching antenna systems (PASS) have recently emerged as a promising architecture for high-frequency wireless communications. In this letter, we investigate localization in PASS by jointly exploiting the received signal amplitude and phase…

Information Theory · Computer Science 2026-02-25 Hao Feng , Ebrahim Bedeer , Ming Zeng , Xingwang Li , Shimin Gong , Quoc-Viet Pham

Third-generation gravitational wave detectors such as Einstein Telescope and Cosmic Explorer will have significantly better sensitivities than current detectors, as well as a wider frequency bandwidth. This will increase the number and…

General Relativity and Quantum Cosmology · Physics 2025-10-22 Tomasz Baka , Harsh Narola , Justin Janquart , Anuradha Samajdar , Tim Dietrich , Chris Van Den Broeck

Improving the phase resolution of interferometry is crucial for high-precision measurements of various physical quantities. Systematic phase errors dominate the phase uncertainties in most realistic optical interferometers. Here we propose…

Quantum Physics · Physics 2018-04-03 Li Li , Yuan Li , You-Lang Zhang , Sixia Yu , Chao-Yang Lu , Nai-Le Liu , Jun Zhang , Jian-Wei Pan

Supermassive black hole binaries are one of the primary targets for gravitational wave searches using pulsar timing arrays. Gravitational wave signals from such systems are well represented by parametrized models, allowing the standard…

Instrumentation and Methods for Astrophysics · Physics 2016-01-25 Yan Wang , Soumya D. Mohanty , Fredrick A. Jenet

To obtain the most accurate pulse arrival times from radio pulsars, it is necessary to correct or mitigate the effects of the propagation of radio waves through the warm and ionised interstellar medium. We examine both the strength of…

Instrumentation and Methods for Astrophysics · Physics 2016-11-15 R. M. Shannon , J. M. Cordes

We propose a set of experiments in which Ramsey-fringe techniques are tailored to probe transitions originating and terminating on the same ground state level. When pulses of resonant radiation, separated by a time delay $% T, $ interact…

Atomic Physics · Physics 2007-05-23 Tycho Sleator , Paul R. Berman , Boris Dubetsky

We propose bigradient phase referencing (BPR), a new radio-observation technique, and report its performance using the Japanese very-long-baseline-interferometry network (JVN). In this method, a weak source is detected by phase-referencing…

In asteroseismology, the observed time series often suffers from incomplete time coverage due to gaps. The presence of periodic gaps may generate spurious peaks in the power spectrum that limit the analysis of the data. Various methods have…

Solar and Stellar Astrophysics · Physics 2015-06-23 Sandrine Pires , Savita Mathur , Rafael A. Garcia , Jérôme Ballot , Dennis Stello , Kumiko Sato