Results 61 to 70 of about 825 (182)
A History of UNAVCO: Four Decades of Advancing Geodesy
Perspectives of Earth and Space Scientists, Volume 6, Issue 1, December 2025.Abstract UNAVCO was a university‐governed consortium funded by the National Science Foundation (NSF), with support from the National Aeronautics and Space Administration (NASA) and the United States Geological Survey (USGS), to support geoscience research and education using geodesy.
Emily E. Zawacki +4 more
wiley +1 more source
Modeling Nearby Low-Luminosity Active-Galactic-Nucleus Jet Images at All VLBI Scales
Galaxies, 2022 Relativistic jets from nearby low-luminosity active-galactic-nuclei (LLAGN) were observed by Very-Long Baseline Interferometry (VLBI) across many orders of magnitude in space, from milliparsec to sub-parsec scales, and from the jet base in the vicinity ...
Hung-Yi Pu +2 more
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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
Multiwavelength VLBI observations of Sagittarius A* [PDF]
Astronomy & Astrophysics, 2010 14pages, 14 Figures, Accepted for publication in A& ...
Lu, R. -S. +7 more
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Spectral Line VLBI Studies Using the ngEHT
Galaxies, 2023 Spectroscopy in the mm/sub-mm wavelength range is a powerful tool to study the gaseous medium in various astrophysical environments. The next generation Event Horizon Telescope (ngEHT) equipped with a wide-bandwidth backend system has great potential for
Dong-Jin Kim, Vincent Fish
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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.
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Globally Critical Infrastructure: The Unique Risks and Challenges
Risk Analysis, Volume 45, Issue 12, Page 4804-4817, December 2025.ABSTRACT Critical infrastructure is typically identified at the national level. However, disruption to certain infrastructure systems, facilities, and assets can have negative consequences for global societies. Such globally critical infrastructure entails a distinct risk profile for both countries dependent on the infrastructure, and countries that ...
Zachary Kallenborn, Henry H. Willis
wiley +1 more source
VERA’s 20 yr Evolution in Science and Technology
GalaxiesWe review the past 20 yr evolution of VERA (VLBI Exploration of Radio Astrometry) in both science and techinology. VERA is a VLBI array in Japan which consists of four 20 m-diameter telescopes, originally dedicated to phase-referencing VLBI astrometry ...
Mareki Honma +3 more
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Eos, Transactions American Geophysical Union, 1983 From the centers of quasars calculated to have velocities 10 times greater than that of light—the Einsteinian constant of the universe—astronomers are finding explanations of Doppler effect red shifts of emission. Very long baseline interferometry (VLBI) arrays have been used to examine the cores of seven known radio sources in space that are ...
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Earth and Space Science, Volume 12, Issue 10, October 2025.Abstract High‐precision Earth Rotation Parameter (ERP) products often experience delays that range from several days to weeks. The use of precise forecasting models can effectively compensate for the impact of such delays. Based on a systematic analysis of the forecasting capabilities of the traditional harmonic least squares fitting and autoregressive
Chen Ren +4 more
wiley +1 more source