Results 61 to 70 of about 822 (179)
Advances in Astronomy, Volume 2026, Issue 1, 2026.This paper investigates the degradation of pointing accuracy in the Kunming 40‐m radio telescope due to long‐term equipment aging and environmental disturbances. Conventional linear pointing models are constrained by their linear modeling framework, making it difficult to accurately represent the nonlinear errors induced by temperature, wind speed, and
Yao He +3 more
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The AUSTRAL VLBI observing program [PDF]
Journal of Geodesy, 2016 The AUSTRAL observing program was started in 2011, performing geodetic and astrometric very long baseline interferometry (VLBI) sessions using the new Australian AuScope VLBI antennas at Hobart, Katherine, and Yarragadee, with contribution from the Warkworth (New Zealand) 12 m and Hartebeesthoek (South Africa) 15 m antennas to make a southern ...
L. Plank +12 more
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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
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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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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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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