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Related papers: A geometric delay model for Space VLBI

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The modern Very Long Baseline Interferometry (VLBI) relativistic delay model, as documented in the IERS Conventions refers to the time epoch when the signal passes one of two stations of an interferometer baseline (selected arbitrarily from…

Instrumentation and Methods for Astrophysics · Physics 2021-01-22 Oleg Titov , Alexei Melnikov , Yulia Lopez

Geodetic Very Long Baseline Interferometry (VLBI) measures the group delay in the barycentric reference frame. As the Earth is orbiting around the Solar system barycentre with the velocity $V$ of 30 km/s, VLBI proves to be a handy tool to…

Instrumentation and Methods for Astrophysics · Physics 2018-10-10 Oleg Titov , Hana Krasna

Very long baseline interferometry (VLBI) provides the resolution needed to make precision measurements of a pulsar's parallax and proper motion. In making these measurements, the astronomer is faced with difficult calibration problems and a…

Astrophysics · Physics 2007-05-23 Walter Brisken

Very Long Baseline Interferometry, or VLBI, is the observing technique yielding the highest-resolution images today. Whilst a traditionally large fraction of VLBI observations is concentrating on Active Galactic Nuclei, the number of…

Astrophysics · Physics 2009-06-23 Enno Middelberg , Uwe Bach

Very Long Baseline Interferometry (VLBI) combines the signals of telescopes distributed across thousands of kilometres to provide some of the highest angular resolution images of astrophysical phenomena. Due to computational expense,…

Instrumentation and Methods for Astrophysics · Physics 2025-04-30 Jack F. Radcliffe , J. P. McKean , C. Herbé-George , L. Coetzer , T. Matsepane

High precision astrometric Space Very Long Baseline Interferometry (S-VLBI) at the low end of the conventional frequency range, i.e. 20cm, is a requirement for a number of high priority science goals. These are headlined by obtaining…

Instrumentation and Methods for Astrophysics · Physics 2015-06-15 R. Dodson , M. Rioja , Y. Asaki , H. Imai , X. -Y. Hong , Z. Shen

Space very long baseline interferometry (VLBI) has unique applications in high-resolution imaging of fine structure of astronomical objects and high-precision astrometry due to the key long space-Earth or space-space baselines beyond the…

Very Long Baseline Interferometry is capable of measuring the gravitational delay caused by the Sun and planet gravitational fields. The post-Newtonian parameter $\gamma$ is now estimated with accuracy of $\sigma_{\gamma}=2\cdot 10^{-4}$…

Instrumentation and Methods for Astrophysics · Physics 2013-11-04 Anastassia Girdiuk , Oleg Titov

The balloon-borne very long baseline interferometry (VLBI) experiment is a technical feasibility study for performing radio interferometry in the stratosphere. The flight model has been developed. A balloon-borne VLBI station will be…

Very Long Baseline Interferometry (VLBI) astrometry is a well established technique for achieving $\pm10~\mu$as parallax accuracies at frequencies well above 10~GHz. At lower frequencies, uncompensated interferometer delays associated with…

Instrumentation and Methods for Astrophysics · Physics 2023-02-15 Lucas J. Hyland , Mark J. Reid , Simon P. Ellingsen , Maria J. Rioja , Richard Dodson , Gabor Orosz , Colin R. Masson , Jamie M. McCallum

The recent development of a relatively inexpensive 16-Gbps data-recording system based on commercial off-the-shelf technology and open-source software, along with parallel development in broadband Very Long Baseline Interferometry (VLBI)…

Our present relativistic part of the geodetic VLBI model for Earthbound antennas is a consensus model which is considered as a standard for processing high-precision VLBI observations. It was created as a compromise between a variety of…

Instrumentation and Methods for Astrophysics · Physics 2017-10-26 Michael Soffel , Sergei Kopeikin , Wen-Biao Han

Very Long Baseline Interferometry (VLBI) provides the finest angular resolution of all astronomical observation techniques. However, observations with Earth-based instruments are approaching fundamental limits on angular resolution. These…

Instrumentation and Methods for Astrophysics · Physics 2025-04-14 Ben Hudson , Leonid I. Gurvits , Daniel Palumbo , Sara Issaoun , Hannah Rana

Finding a suitable very long baseline (VLBI) interferometer geometry is a key task in planning observations, especially imaging sessions. The main characteristic of the quality of VLBI imaging data is the (u, v)-coverage. In the case when…

Instrumentation and Methods for Astrophysics · Physics 2024-04-01 I. I. Bulygin , M. A. Shchurov , A. G. Rudnitskiy

5,000,000 VLBI delays are stored now in the IVS data base and available for scientific analysis. This is a remarkable result of more than 20 years of geodetic VLBI history. This paper presents some statistics related to the VLBI…

Geophysics · Physics 2011-02-04 Zinovy Malkin

Very-long-baseline interferometry (VLBI) at frequencies above 230 GHz with Earth-diameter baselines gives spatial resolution finer than the ${\sim}50 \mu$as "shadow" of the supermassive black hole at the Galactic Center, Sagittarius A* (Sgr…

Instrumentation and Methods for Astrophysics · Physics 2019-08-21 Daniel C. M. Palumbo , Sheperd S. Doeleman , Michael D. Johnson , Katherine L. Bouman , Andrew A. Chael

Optical Very Long Baseline Interferometry (VLBI) offers the potential for unprecedented angular resolution in both astronomical imaging and precision measurements. Classical approaches, however, face significant limitations due to photon…

Quantum Physics · Physics 2025-12-24 Zixin Huang , Oleg Titov , Mikolaj K. Schmidt , Benjamin Pope , Gavin K. Brennen , Daniel Oi , Pieter Kok

We discuss the technique of Wide-field imaging as it applies to Very Long Baseline Interferometry (VLBI). In the past VLBI data sets were usually averaged so severely that the field-of-view was typically restricted to regions extending a…

Astrophysics · Physics 2009-10-31 M. A. Garrett , R. W. Porcas , A. Pedlar , T. W. B. Muxlow , S. T. Garrington

Extension of radio interferometric baselines into space is inevitable if a diffraction-limited angular resolution defined by the Earth diameter at a given observing wavelength limits a pursuit of specific scientific goals. This was…

Instrumentation and Methods for Astrophysics · Physics 2018-10-03 Leonid I. Gurvits

Space Very Long Baseline Interferometry is a radio astronomy technique distinguished by a record-high angular resolution reaching single-digit microseconds of arc. The paper provides a brief account of the history of developments of this…

Instrumentation and Methods for Astrophysics · Physics 2023-12-27 Leonid I. Gurvits
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