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Phase stability at low radio frequencies is severely impacted by ionospheric propagation delays. Radio interferometers such as the Giant Metrewave Radio Telescope (GMRT) are capable of detecting changes in the ionosphere's total electron…

Instrumentation and Methods for Astrophysics · Physics 2025-07-01 Dipanjan Banerjee , Abhik Ghosh , Sushanta K Mondal , Parimal Ghosh

LOFAR is the LOw Frequency Radio interferometer ARray located at mid-latitude ($52^{\circ} 53'N$). Here, we present results on ionospheric structures derived from 29 LOFAR nighttime observations during the winters of 2012/2013 and…

The Earth's ionosphere introduces systematic effects that limit the performance of a radio interferometer at low frequencies ($\lesssim 1$\,GHz). These effects become more pronounced for severe geomagnetic activities or observations…

Earth and Planetary Astrophysics · Physics 2023-02-02 Sarvesh Mangla , Sumanjit Chakraborty , Abhirup Datta , Ashik Paul

We present a study of scintillation induced by the mid-latitude ionosphere. By implementing methods currently used in Interplanetary Scintillation studies to measure amplitude scintillation at low frequencies, we have proven it is possible…

Instrumentation and Methods for Astrophysics · Physics 2022-09-14 A. Waszewski , J. Morgan , C. H. Jordan

We report on slow phase variations of the response of the space-ground radio interferometer RadioAstron during observations of pulsar B0329+54. The phase variations are due to the ionosphere and clearly distinguishable from effects of…

Astrophysics of Galaxies · Physics 2021-07-14 M. V. Popov , N. Bartel , M. S. Burgin , T. V. Smirnova , V. A. Soglasnov

The low-latitude ionosphere is a dynamic region with a wide range of disturbances in temporal and spatial scales. The Giant Metrewave Radio Telescope (GMRT) situated in the low-latitude region has demonstrated its ability to detect various…

Space Physics · Physics 2023-07-13 Sarvesh Mangla , Abhirup Datta

A tomographic method is described to quantify the three-dimensional power-spectrum of the ionospheric electron-density fluctuations based on radio-interferometric observations by a two-dimensional planar array. The method is valid to…

Instrumentation and Methods for Astrophysics · Physics 2015-05-18 L. V. E. Koopmans

The ionosphere is the main driver of a series of systematic effects that limit our ability to explore the low frequency (<1 GHz) sky with radio interferometers. Its effects become increasingly important towards lower frequencies and are…

Instrumentation and Methods for Astrophysics · Physics 2018-08-08 F. de Gasperin , M. Mevius , D. A. Rafferty , H. T. Intema , R. A. Fallows

Ionospheric irregularities and associated scintillations under geomagnetically active/quiet conditions have detrimental effects on the reliability and performance of space- and ground-based navigation satellite systems, especially over the…

Space Physics · Physics 2024-10-24 Sumanjit Chakraborty , Abhirup Datta

The understanding of inertial-scale dynamics in the heliosheath is not yet thorough. Magnetic field fluctuations across the inner heliosheath (IHS) and the local interstellar medium (LISM) are here considered to provide accurate and highly…

The turbulent ionosphere causes phase shifts to incoming radio waves on a broad range of temporal and spatial scales. When an interferometer is not sufficiently calibrated for the direction-dependent ionospheric effects, the time-varying…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-02 S. A. Brackenhoff , M. Mevius , L. V. E. Koopmans , A. Offringa , E. Ceccotti , J. K. Chege , B. K. Gehlot , S. Ghosh , C. Höfer , F. G. Mertens , S. Munshi , S. Zaroubi

Calibration of radio interferometric observations becomes increasingly difficult towards lower frequencies. Below ~300 MHz, spatially variant refractions and propagation delays of radio waves traveling through the ionosphere cause phase…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 H. T. Intema , S. van der Tol , W. D. Cotton , A. S. Cohen , I. M. van Bemmel , H. J. A. Rottgering

The circumgalactic medium (CGM) is poorly constrained at the sub-parsec scales relevant to turbulent energy dissipation and regulation of multi-phase structure. Fast radio bursts (FRBs) are sensitive to small-scale plasma density…

Astrophysics of Galaxies · Physics 2025-07-25 S. K. Ocker , M. Chen , S. P. Oh , P. Sharma

By means of three dimensional high-resolution hybrid simulations we study the properties of the magnetic field spectral anisotropies near and beyond ion kinetic scales. By using both a Fourier analysis and a local analysis based on…

Solar and Stellar Astrophysics · Physics 2019-04-18 Simone Landi , Luca Franci , Emanuele Papini , Andrea Verdini , Lorenzo Matteini , Petr Hellinger

For a ground-based radio interferometer observing at low frequencies, the ionosphere causes propagation delays and refraction of cosmic radio waves which result in phase errors in the received signal. These phase errors can be corrected…

Instrumentation and Methods for Astrophysics · Physics 2016-04-14 Poppy L. Martin , Justin D. Bray , Anna M. M. Scaife

Refraction and diffraction of incoming radio waves by the ionosphere induce time variability in the angular positions, peak amplitudes and shapes of radio sources, potentially complicating the automated cross-matching and identification of…

High spatial and temporal resolution images of a sunspot, obtained simultaneously in multiple optical and UV wavelengths, are employed to study the propagation and damping characteristics of slow magnetoacoustic waves up to transition…

Solar and Stellar Astrophysics · Physics 2017-09-20 S. Krishna Prasad , D. B. Jess , T. Van Doorsselaere , G. Verth , R. J. Morton , V. Fedun , R. Erdelyi , D. J. Christian

We present results of observation of Cygnus-A radiosource scintillation in the Earth's ionosphere in quiet and disturbed geomagnetic condition at Irkutsk incoherent scattering radar (IISR). Scintillation method applied for ionosphere…

Context: The interstellar medium (ISM) on all scales is full of structures that can be used as tracers of processes that feed turbulence. Aims: We used HI survey data to derive global properties of the angular power distribution of the…

Astrophysics of Galaxies · Physics 2019-07-02 P. M. W. Kalberla , U. Haud
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