Results 71 to 80 of about 22,374 (269)
Astrometric Apparent Motion of High-redshift Radio Sources
The 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
VLBI Activities in Japan and a Projected Space-VLBI Program [PDF]
Symposium - International Astronomical Union, 1988 There are three institutes in Japan that are equipped with VLBI facilities. Of these, Nobeyama Radio Observatory started VLBI experiments with astrophysical and astrometric interests. The Institute of Space and Astronautical Science, the Nobeyama Radio Observatory, and the Radio Research Laboratory collaborated with JPL and other institutions for this ...
openaire +1 more source
Proceedings of 8th European VLBI Network Symposium — PoS(8thEVN), 2007 Systematic surveys of astronomical objects often lead to discoveries, but always provide invaluable information for statistical studies of well-defined samples. They also promote follow-up investigations of individual objects or classes. Surveys using a yet unexplored observing wavelength, a novel technique or a new instrument are of special importance.
openaire +2 more sources
A Concept of Precise VLBI/GNSS Ties with Micro-VLBI
, 2023 AbstractWe present here a concept of measuring local ties between collocated GNSS and VLBI stations using the microwave technique that effectively transforms a GNSS receiver to an element of a VLBI network. This is achieved by modifying the signal chain that allows to transfer voltage of the GNSS antenna to a digitizer via a coaxial cable.
Leonid Petrov +5 more
openaire +1 more source
MSWD: A Hybrid Machine‐Learning Framework for Slant Wet Delay Modeling
Journal of Geophysical Research: Atmospheres, Volume 131, Issue 12, 28 June 2026.Abstract Space geodetic techniques such as Global Navigation Satellite Systems (GNSS) and Very Long Baseline Interferometry (VLBI) are limited by direction‐dependent tropospheric delays, with slant wet delay (SWD) being the most variable component and a major error source.
Zhenyi Zhang, Benedikt Soja
wiley +1 more source
First proof of concept of remote attendance for future observation strategies between Wettzell (Germany) and Concepción (Chile) [PDF]
, 2010 Current VLBI observations are controlled and attended locally at the radio telescopes on the basis of pre-scheduled session files. Operations have to deal with system specific station commands and individual setup procedures.
Hase, H +9 more
core
Multi-Maser VLBI structure of the high-mass SFR G16.59-0.05 [PDF]
, 2008 In the following we summarize our results based on multi-epoch, phase referenced, Very Long Baseline Interferometry (VLBI) observations of maser associations towards the high-mass Star Forming Region (SFR) G16.59-0.05. We observed H2O 22.2 GHz (4 epochs)
Riccardo Cesaroni +9 more
core +1 more source
Detection of Intrinsic Source Structure at ∼3 Schwarzschild Radii with Millimeter-VLBI Observations of SAGITTARIUS A* [PDF]
, 2018 We report results from very long baseline interferometric (VLBI) observations of the supermassive black hole in the Galactic center, Sgr A*, at 1.3 mm (230 GHz). The observations were performed in 2013 March using six VLBI stations in Hawaii, California,
R. Lu +55 more
semanticscholar +1 more source
A quantitative analysis of systematic differences in the positions and proper motions of Gaia DR2 with respect to VLBI [PDF]
Monthly notices of the Royal Astronomical Society, 2018 We have analysed the differences in positions of 9081 matched sources between the Gaia Data Release 2 (DR2) and very long baseline interferometry (VLBI) catalogues. The median position uncertainty of matched sources in the VLBI catalogue is a factor of
L. Petrov +5 more
semanticscholar +1 more source
Symposium - International Astronomical Union, 1994 VLBI is at present the most accurate technique for measuring radiosource positions and the only method capable of high precision for a reasonable number of sources. The applications of VLBI astrometry in stellar, Galactic and extra-Galactic regimes are reviewed.
openaire +1 more source