Results 101 to 110 of about 27,573 (245)
Describing the uncertainties in VLBI images [PDF]
We are investigating a new approach to modelling uncertainties in individual pixels of Very Long Baseline Interferometry (VLBI) intensity (Stokes I, Q, U) images. Comparison of distributions of our calculated uncertainties for model sources with the results of Monte Carlo simulations shows that our method correctly reproduces the overall level and ...
Coughlan, Colm P., Gabuzda, Denise C.
openaire +2 more sources
Evaluate the Prediction Level of Polar Motion Interpolation for 6 hr in Ideal and Real Environments
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
Radio observations of active galactic nuclei with mm-VLBI [PDF]
Over the past few decades, our knowledge of jets produced by active galactic nuclei (AGN) has greatly progressed thanks to the development of very-long-baseline interferometry (VLBI).
B. Boccardi +3 more
semanticscholar +1 more source
The AUSTRAL VLBI observing program [PDF]
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
openaire +3 more sources
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
wiley +1 more source
Modeling Nearby Low-Luminosity Active-Galactic-Nucleus Jet Images at All VLBI Scales
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
doaj +1 more source
Multiwavelength VLBI observations of Sagittarius A* [PDF]
14pages, 14 Figures, Accepted for publication in A& ...
Lu, R. -S. +7 more
openaire +2 more sources
A History of UNAVCO: Four Decades of Advancing Geodesy
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
Spectral Line VLBI Studies Using the ngEHT
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
doaj +1 more source
VLBI Observations of the Nucleus of Centaurus A [PDF]
VLBI observations of the nucleus of Centaurus A have been made at three southern hemisphere observatories. Since Centaurus A is the nearest active galaxy, VLBI investigations are important because the physical processes in the nucleus can be studied in greater linear detail than in other similar galaxies.
R. A. Preston +7 more
openaire +1 more source

