中文
相关论文

相关论文: A measurement of small-scale features using ionosp…

200 篇论文

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…

Observation of interplanetary scintillation (IPS) beyond Earth-orbit can be challenging due to the necessity to use low radio frequencies at which scintillation due to the ionosphere could confuse the interplanetary contribution. A recent…

天体物理仪器与方法 · 物理学 2016-09-07 R. A. Fallows , M. M. Bisi , B. Forte , Th. Ulich , A. A. Konovalenko , G. Mann , C. Vocks

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…

星系天体物理 · 物理学 2021-07-14 M. V. Popov , N. Bartel , M. S. Burgin , T. V. Smirnova , V. A. Soglasnov

We present the first dedicated observations of Interplanetary Scintillation (IPS) with the Murchison Widefield Array (MWA). We have developed a synthesis imaging technique, tailored to the properties of modern "large-N" low-frequency radio…

天体物理仪器与方法 · 物理学 2017-09-12 J . S. Morgan , J-P. Macquart , R. Ekers , R. Chhetri , M. Tokumaru , P. K. Manoharan , S. Tremblay , M. M. Bisi , B. V. Jackson

Ionospheric scintillation is the rapid change in the phase and/or the amplitude of a radio signal as it passes through small scale plasma density irregularities in the ionosphere. These scintillations not only can reduce the accuracy of…

大气与海洋物理 · 物理学 2012-08-10 S. Priyadarshi , A. K. Singh

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…

空间物理 · 物理学 2026-04-14 Dipanjan Banerjee , Abhik Ghosh , Sushanta K. Mondal , Parimal Ghosh

High resolution (~1 arcminute) astronomical imaging at low frequency (below 150 MHz) has only recently become practical with the development of new calibration algorithms for removing ionospheric distortions. In addition to opening a new…

天体物理仪器与方法 · 物理学 2015-05-13 A. S. Cohen , H. J. A. Röttgering

In this paper, we consider random phase fluctuations imposed during wave propagation through a turbulent plasma (e.g. ionosphere) as a source of additional noise in interferometric visibilities. We derive expressions for visibility variance…

天体物理仪器与方法 · 物理学 2015-12-02 H. K. Vedantham , L. V. E. Koopmans

We detail new techniques for analysing ionospheric activity, using Epoch of Reionisation (EoR) datasets obtained with the Murchison Widefield Array (MWA), calibrated by the `Real-Time System' (RTS). Using the high spatial- and…

天体物理仪器与方法 · 物理学 2017-08-30 C. H. Jordan , S. Murray , C. M. Trott , R. B. Wayth , D. A. Mitchell , M. Rahimi , B. Pindor , P. Procopio , J. Morgan

We describe the parameters of a low-frequency all-sky survey of compact radio sources using Interplanetary Scintillation (IPS), undertaken with the Murchison Widefield Array (MWA). While this survey gives important complementary information…

星系天体物理 · 物理学 2019-02-08 J. S. Morgan , J-P. Macquart , R. Chhetri , R. D. Ekers , S. J. Tingay , E. M. Sadler

We present observations of high-amplitude rapid (2 s) variability toward two bright, compact extragalactic radio sources out of several hundred of the brightest radio sources in one of the 30x30 deg MWA Epoch of Reionization fields using…

The Earth's ionosphere refracts radio signals, shifting the apparent position of radio sources. Wide-field measurements with a radio interferometer can measure the ionospheric distortion. The Murchison Widefield Array (MWA) has the ability…

Changes in the sky noise spectrum are used to characterize perturbations in the ionosphere. Observations were made at the same sidereal time on multiple days using a calibrated broadband dipole and radio spectrometer covering 80 to 185 MHz.…

天体物理仪器与方法 · 物理学 2015-06-23 Alan E. E. Rogers , Judd D. Bowman , Juha Vierinen , Raul Monsalve , Thomas Mozdzen

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…

空间物理 · 物理学 2023-07-13 Sarvesh Mangla , Abhirup Datta

The results of a climatological study of ionospheric disturbances derived from observations of cosmic sources from the Very Large Array (VLA) Low-frequency Sky Survey (VLSS) are presented. We have used the ionospheric corrections applied to…

空间物理 · 物理学 2015-06-11 J. F. Helmboldt , W. M. Lane , W. D. Cotton

Intensity scintillations of cosmic radio sources are used to study astrophysical plasmas like the ionosphere, the solar wind, and the interstellar medium. Normally these observations are relatively narrow band. With Low Frequency Array…

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…

地球物理 · 物理学 2017-02-08 Roman Vasilyev , Mariia Globa , Dmitry Kushnarev , Andrey Medvedev , Konstantin Ratovsky

Visibility scintillation resulting from wave propagation through the turbulent ionosphere can be an important sources of noise at low radio frequencies ($\nu\lesssim 200$ MHz). Many low frequency experiments are underway to detect the power…

天体物理仪器与方法 · 物理学 2016-03-16 H. K. Vedantham , L. V. E. Koopmans
‹ 上一页 1 2 3 10 下一页 ›