Results 81 to 90 of about 822 (179)
Linking Planetary Ephemeris Reference Frames to ICRF via Millisecond Pulsars
UniverseThe positions of millisecond pulsars (MSPs) can be determined with sub-milliarcsecond (mas) accuracy using both Very Long Baseline Interferometry (VLBI) and timing, referenced to the International Celestial Reference Frame (ICRF) and planetary ...
Li Guo +4 more
doaj +1 more source
Earth and Space Science, Volume 12, Issue 6, June 2025.Abstract The findings from the Second Earth Orientation Parameters Prediction Comparison Campaign (2nd EOP PCC) suggest that integrating effective angular momentum (EAM) is vital for enhancing the accuracy of polar motion (PM) predictions. Building on Dill et al.
Wei Miao +3 more
wiley +1 more source
Annals of Geophysics, 2010 Very-long-baseline interferometry (VLBI) is used for establishing global geodetic networks where the coordinates attain a 1-mm level of precision. Technique-dependent bias can degrade the VLBI positioning accuracy if it is present and unaccounted for ...
Claudio Abbondanza +2 more
doaj +1 more source
New Astronomy Reviews, 1999 We discuss the technique of Wide-field imaging as it applies to Very Long Baseline Interferometry (VLBI). In the past VLBI data sets were usually averaged so severely that the field-of-view was typically restricted to regions extending a few hundred milliarcseconds from the phase centre of the field.
Garrett, M. A. +4 more
openaire +2 more sources
Journal of Geophysical Research: Solid Earth, Volume 130, Issue 6, June 2025.Abstract Non‐tidal loading (NTL) introduces surface deformation on the Earth and increases the variability in coordinates measured by space geodetic techniques. Correcting NTL displacements in Global Navigation Satellite Systems (GNSS) analysis has been discussed extensively, commonly at the parameter level.
Jungang Wang +6 more
wiley +1 more source
Studying the Inner Heliosphere Using Radio Signals Transmitted From Spacecraft Orbiting Mars
Space Weather, Volume 23, Issue 5, May 2025.Abstract In this campaign, we used very long baseline interferometry (VLBI) radio telescopes to track the carrier radio signal transmitted from spacecraft orbiting Mars during the Mars solar conjunction. The campaign extended from September 6th $6\text{th}$ to November 6th $6\text{th}$ 2021 and targeted the Mars Express (MEX) and Tianwen‐1 (TIW ...
J. Edwards +4 more
wiley +1 more source
The Structure and Propagation of the Misaligned Jet M87
Galaxies, 2016 Due to its proximity, M87 is a prime target for next-generation high-resolution VLBI at short millimeter wavelengths, by which the jet launching region and the black hole shadow are expected to be resolved and imaged sometime soon.
Kazuhiro Hada
doaj +1 more source
Extragalactic VLBI at 89 GHZ [PDF]
Symposium - International Astronomical Union, 1984 Radio interferometry at 89 GHz with transcontinental baselines can probe the region of active galaxies and quasars where collimation of relativistic outflows occur on length scales of 1017–18cm. Three experiments have been conducted recently to demonstrate the feasability and importance of this investigation.
openaire +1 more source
Parallaxes and Proper Motions of Long Period Variable Stars Determined from VLBI and Gaia DR3
GalaxiesAnnual parallaxes of Galactic long period variable stars (LPVs) are essential for determining their distances and intrinsic properties, but their measurement remains challenging because of their large stellar sizes, circumstellar matter, and time ...
Akiharu Nakagawa +3 more
doaj +1 more source
, 2008 We review VLBI observations of supernovae over the last quarter century and discuss the prospect of imaging future supernovae with space VLBI in the context of VSOP-2. From thousands of discovered supernovae, most of them at cosmological distances, ~50 have been detected at radio wavelengths, most of them in relatively nearby galaxies. All of the radio
openaire +2 more sources