Results 41 to 50 of about 27,390 (189)

A new method for estimating frequency-dependent core shifts in active galactic nucleus jets [PDF]

, 2011
We discuss the opacity in the core regions of active galactic nuclei observed with Very Long Baseline Interferometry (VLBI), and describe a new method for deriving the frequency-dependent shifts of the VLBI core from the frequency-dependent time lags of ...
Aller, H. D., Aller, M. F., Gabuzda, D. C., Kudryavtseva, N. A.   +3 more
core   +3 more sources

Wide-field VLBI imaging

New Astronomy Reviews, 1999
6 pages, 3 figures, accepted by New Astronomy Reviews, EVN/JIVE Symposium Special ...
Garrett, M. A., Porcas, R. W., Pedlar, A., Muxlow, T. W. B., Garrington, S. T.   +4 more
openaire   +2 more sources

An Experiment on Radio Location of Objects in the Near-Earth Space with VLBI in 2012

Open Astronomy, 2013
An experiment on radar location of space debris objects using of the method of VLBI was carried out in April, 2012. The radar VLBI experiment consisted in irradiation of some space debris objects (4 rocket stages and 5 inactive satellites) with a signal ...
Nechaeva M., Antipenko A., Bezrukovs V., Bezrukov D., Dementjev A., Dugin N., Konovalenko A., Kulishenko V., Liu X., Nabatov A., Nesteruk V., Pupillo G., Reznichenko A., Salerno E., Shmeld I., Shulga O., Sybiryakova Y., Tikhomirov Yu., Tkachenko A., Volvach A., Yang W.-J.   +20 more
doaj   +1 more source

Evaluate the Prediction Level of Polar Motion Interpolation for 6 hr in Ideal and Real Environments

Earth and Space Science, Volume 13, Issue 1, January 2026.
Abstract With the increasing demands for global development, deep space exploration missions are taking place more frequently, rendering the traditional 24‐hr Polar Motion (PM) predictions inadequate for supporting the frequent operations of spacecraft.
Wei Miao, Xueqing Xu, Yonghong Zhou
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  

1.3 mm Wavelength VLBI of Sagittarius A*: Detection of Time-Variable Emission on Event Horizon Scales [PDF]

, 2010
Sagittarius A*, the ~4 x 10^6 solar mass black hole candidate at the Galactic Center, can be studied on Schwarzschild radius scales with (sub)millimeter wavelength Very Long Baseline Interferometry (VLBI).
Beaudoin, Christopher, Blundell, Ray, Bolin, David E., Bower, Geoffrey C., Chamberlin, Richard, Doeleman, Sheperd S., Fish, Vincent L., Freund, Robert, Friberg, Per, Gurwell, Mark A., Honma, Mareki, Inoue, Makoto, Krichbaum, Thomas P., Lamb, James, Marrone, Daniel P., Moran, James M., Oyama, Tomoaki, Plambeck, Richard, Primiani, Rurik, Rogers, Alan E. E., Smythe, Daniel L., SooHoo, Jason, Strittmatter, Peter, Tilanus, Remo P. J., Titus, Michael, Weintroub, Jonathan, Woody, David, Wright, Melvyn, Young, Ken H., Ziurys, Lucy M.   +29 more
core   +3 more sources

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

РАДИОСТРУКТУРА ИСТОЧНИКА 1803÷784

Odessa Astronomical Publications, 2011
Results of processing of data of ground-space VLBI experiment titled V053 are presented. These observations were made in 1997 October with 10 antennas of American interferometer VLBA and with Japan space telescope VSOP (VLBI Space Orbit Program).
A. А. Чуприков
doaj   +1 more source

On the Calibration of Full-polarization 86GHz Global VLBI Observations [PDF]

, 2012
We report the development of a semi-automatic pipeline for the calibration of 86 GHz full-polarization observations performed with the Global Millimeter-VLBI array (GMVA) and describe the calibration strategy followed in the data reduction.
Alef, W., Anderson, J. M., Bach, U., Bertarini, A., Bremer, M., Krichbaum, T. P., Lindqvist, M., Marscher, A., Marti-Vidal, I., Mujunen, A., Rottmann, H., Sanchez, S., Schinzel, F. K., Zensus, J. A.   +13 more
core   +2 more sources

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