Results 71 to 80 of about 27,573 (245)

Decoherence in LOFAR-VLBI beamforming [PDF]

open access: yesAstronomy & Astrophysics, 2020
We show that the use of a superstation (a phased array created using multiple stations of an interferometric array) created in post-processing for LOFAR-VLBI observations introduces a direction-dependent loss of signal in the image. We show this effect using simulations and real data.
Bonnassieux E.   +3 more
openaire   +3 more sources

A Study on the Development of Playback Control Software for Mark5B VSI System [PDF]

open access: yesJournal of Astronomy and Space Sciences, 2010
We developed the playback control software for a high-speed playback system which is a component of the Korea-Japan Joint VLBI Correlator (KJJVC). The Mark5B system, which is a recorder and playback system used in the Korean VLBI Network (KVN), has two
S. J. Oh   +5 more
doaj   +1 more source

Space VLBI: from first ideas to operational missions [PDF]

open access: yesAdvances in Space Research, 2019
The operational period of the first generation of dedicated Space VLBI (SVLBI) missions commenced in 1997 with the launch of the Japan-led mission VSOP/HALCA and is coming to closure in 2019 with the completion of in-flight operations of the Russia-led ...
L. Gurvits
semanticscholar   +1 more source

Ground Based VLBI Facilities - the European and Global VLBI Network [PDF]

open access: yes, 2004
11 pages, 5 figures, lecture presented at the NATA ASI VLBI School, Oct 2001. To be published in "The Role of VLBI in Astrophysics, Astrometry and Geodesy", ed. F. Mantovani.
openaire   +2 more sources

Preparation of the VIRAC Radio Telescope RT-32 for e-VLBI Observations

open access: yesOpen Astronomy, 2013
A fully steerable parabolic antenna RT-32 with the mirror diameter 32 m owned by the Ventspils International Radio Astronomy Centre (VIRAC) is available for fundamental and applied research in radio astronomy.
Skirmante K.   +3 more
doaj   +1 more source

Astrometric Apparent Motion of High-redshift Radio Sources

open access: yesThe Astronomical Journal, 2023
Radio-loud quasars at high redshift ( z ≥ 4) are rare objects in the universe and rarely observed with Very Long Baseline Interferometry (VLBI). But some of them have flux density sufficiently high for monitoring of their apparent position.
Oleg Titov   +12 more
doaj   +1 more source

A comparison of the local spiral structure from Gaia DR2 and VLBI maser parallaxes [PDF]

open access: yesAstronomy & Astrophysics, 2018
Context. The Gaia mission has released the second data set (Gaia DR2), which contains parallaxes and proper motions for a large number of massive, young stars. Aims.
Ye Xu   +10 more
semanticscholar   +1 more source

Space VLBI [PDF]

open access: yesSymposium - International Astronomical Union, 2001
Space VLBI enables high angular resolution and high dynamic range imaging through an extension of ground-based VLBI. The TDRSS space VLBI experiments in the 1980s were followed by the first space VLBI imaging mission, VSOP, in the 1990s. The new century holds the promise of the VSOP-2 and ARISE missions, which aim for more sensitive, higher angular ...
openaire   +1 more source

VLBI architecture of a compact binary with exoplanet

open access: yes, 2023
Very Long Baseline Interferometry (VLBI) offers astrometric precision of tens of micro-arseconds, which is comparable to that offered by the Gaia mission.
Ortiz-Leon, Gisela
core   +1 more source

An Experiment on Radio Location of Objects in the Near-Earth Space with VLBI in 2012

open access: yesOpen Astronomy, 2013
An experiment on radar location of space debris objects using of the method of VLBI was carried out in April, 2012. The radar VLBI experiment consisted in irradiation of some space debris objects (4 rocket stages and 5 inactive satellites) with a signal ...
Nechaeva M.   +20 more
doaj   +1 more source

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