Results 31 to 40 of about 15,217 (172)

A New Very Long Baseline Interferometry Method Based on the Uplink Signal

open access: yesIEEE Access, 2020
Very long baseline interferometry (VLBI) is widely used for astronomical observations and navigation of deep space receivers. To solve the problems of the downlink signal being excessively weak to be received and the excessively large acquisition time, a
Linshan Xue, Weiren Wu, Xue Li
doaj   +1 more source

Favorable locations for new VGOS antennas in India depending on the assessment of geodetic parameters and environmental factors

open access: yesEarth, Planets and Space, 2023
VLBI simulation studies are carried out to investigate the impact of any proposed station or strategy on the geodetic parameters, such as Earth Orientation Parameters (EOP) and Terrestrial Reference Frame (TRF). In general, such studies are performed for
Sujata Dhar   +5 more
doaj   +1 more source

Data Handling within the International VLBI Service

open access: yesData Science Journal, 2013
The International VLBI Service for Geodesy and Astrometry (IVS) is a globally operating service that coordinates and performs Very Long Baseline Interferometry (VLBI) activities through its constituent components.
Dirk Behrend
doaj   +1 more source

VLBI with TDRSS [PDF]

open access: yesInternational Astronomical Union Colloquium, 1990
AbstractVLBI observations using a satellite in earth orbit and ground antennas in Japan and Australia were conducted in 1986, 1987, and 1988. Sources were detected on space-ground baselines at both observing frequencies: 2.3 and 15 GHz. The coherence on space-ground baselines for 340 s was 90% at 2.3 GHz and 76% at 15 GHz.
openaire   +1 more source

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

Software and Techniques for VLBI Data Processing and Analysis

open access: yesUniverse, 2022
Very-long-baseline interferometry (VLBI) is a challenging observational technique, which requires in-depth knowledge about radio telescope instrumentation, interferometry, and the handling of noisy data.
Michael Janssen   +2 more
doaj   +1 more source

mm VLBI

open access: yes, 1993
Very long Baseline Interferometry (VLBI) has now made its break-through into the mm wavelength regime. A global VLBI array has produced maps of radio sources at 3 mm since 1988 and development is under way to improve the sensitivity for VLBI also at 1 mm.
Bååth, Lars B.,
core   +2 more sources

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

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

Home - About - Disclaimer - Privacy