Results 51 to 60 of about 27,737 (204)

FinalKAN: A Dual‐Stream KAN Network Integrating Multisource Features for Radio Telescope Pointing Correction

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, Longfei Hao, Wei Dai, Fernando Aguado Agelet   +3 more
wiley   +1 more source

Zooming towards the Event Horizon - mm-VLBI today and tomorrow [PDF]

, 2013
Global VLBI imaging at millimeter and sub-millimeter wavelength overcomes the opacity barrier of synchrotron self-absorption in AGN and opens the direct view into sub-pc scale regions not accessible before.
Alef, W., Angelakis, E., Bertarini, A., Blundell, R., Bremer, M., Doeleman, S., Fish, V., Freund, R., Fuhrmann, L., Hodgson, J. A., Jorstad, S. G., Karamanavis, V., Krichbaum, T. P., Marrone, D., Marscher, A. P., Rottmann, H., Roy, A., Sanchez, S., Strittmatter, P., Wagner, J., Weintroub, J., Young, K., Zensus, J. A., Ziurys, L.   +23 more
core  

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, Donna J. Charlevoix, Charles M. Meertens, Jeffrey T. Freymueller, Tonie van Dam   +4 more
wiley   +1 more source

The influence of Galactic aberration on precession parameters determined from VLBI observations [PDF]

, 2010
The influence of proper motions of sources due to Galactic aberration on precession models based on VLBI data is determined. Comparisons of the linear trends in the coordinates of the celestial pole obtained with and without taking into account Galactic ...
A. M. Clerke, C. Ma, E. A. Popova, J. Kovalevsky, J. L. Fanselow, J.-C. Liu, N. Capitaine, N. Capitaine, O. J. Sovers, O. Titov, O. Titov, O. Titov, O. Titov, O. Titov, O. Titov, S. A. Klioner, S. Kopeikin, T. M. Eubanks, V. E. Zharov, V. E. Zharov, V. V. Bobylev, V. V. Bobylev, W. Schlüter, Z. M. Malkin, Z. M. Malkin, Z. M. Malkin, Z. M. Malkin, Z. M. Malkin, Z. Malkin, Z. Malkin, Z. Malkin   +30 more
core   +1 more source

VLBI Pulsar Astrometry [PDF]

Symposium - International Astronomical Union, 2001
I briefly review the means by which VLBI observations can determine the position, proper motion, and parallax of a pulsar, consider a subset of the applications of such results, and highlight recent developments in pulsar gating at JIVE.
openaire   +1 more source

Decoherence in LOFAR-VLBI beamforming [PDF]

Astronomy & 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., Edge A., Morabito L., Bonafede A.   +3 more
openaire   +3 more sources

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, Keiichi Asada, Masanori Nakamura   +2 more
doaj   +1 more source

The Gould's Belt Distances Survey

, 2012
Very Long Baseline Interferometry (VLBI) observations can provide the position of compact radio sources with an accuracy of order 50 micro-arcseconds. This is sufficient to measure the trigonometric parallax and proper motions of any object within 500 pc
Loinard, Laurent
core   +1 more source

5 year Global 3-mm VLBI survey of Gamma-ray active blazars [PDF]

, 2015
The Global mm-VLBI Array (GMVA) is a network of 14 3\,mm and 7\,mm capable telescopes spanning Europe and the United States, with planned extensions to Asia.
Bremer, M., de Vicente, P., Hodgson, J. A., Jorstad, S. G., Krichbaum, T. P., Lindqvist, M., Marscher, A. P., Marti-Vidal, I., Sanchez, S., Zensus, J. A.   +9 more
core   +2 more sources

VLBI with TDRSS [PDF]

International 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