Results 21 to 30 of about 424 (141)

HINOTORI and Its Perspectives in the Black-Hole Jet Study

Galaxies, 2023
Simultaneous multi-band very long baseline interferometry (VLBI) observations at millimeter wavelengths have huge potential for various science cases.
Toshihisa Tsutsumi, Kotaro Niinuma, Hiroshi Imai, Ryoko Amari, Yusuke Shimizu, Hideo Ogawa, Atsushi Nishimura, Chieko Miyazawa, Tomoaki Oyama, Hiroyuki Kaneko, Keisuke Nakashima, Satoko Sawada-Satoh, Takahiro Aoki   +12 more
doaj   +1 more source

Initial Results Obtained with the First TWIN VLBI Radio Telescope at the Geodetic Observatory Wettzell

Sensors, 2015
Geodetic Very Long Baseline Interferometry (VLBI) uses radio telescopes as sensor networks to determine Earth orientation parameters and baseline vectors between the telescopes.
Torben Schüler, Gerhard Kronschnabl, Christian Plötz, Alexander Neidhardt, Alessandra Bertarini, Simone Bernhart, Laura la Porta, Sebastian Halsig, Axel Nothnagel   +8 more
doaj   +1 more source

Experience from geodetic very long baseline interferometry observations at Onsala using a digital backend

Journal of Geodetic Science, 2015
The Onsala Space Observatory has installed a modern digital backend for geodetic and astronomical Very Long Baseline Interferometry (VLBI). This system consists of a Digital Base-Band Converter (DBBC) and a Mark 5B+ recorder.
Kareinen N., Haas R.
doaj   +1 more source

The Role of Spatial Gradient on Vertical Total Electron Content Extraction From Geodetic Very Long Baseline Interferometry Observation: Case Study CONT08 to CONT17‐L1

Space Weather, 2021
Geodetic very long baseline interferometry (VLBI) observations are carried out, with the legacy system, using two well‐separated frequency bands in order to determine first‐order ionospheric delay corrections corresponding to the combined effect of total
Hossein Etemadfard, Robert Heinkelmann, Masoud Mashhadi Hossainali, Harald Schuh   +3 more
doaj   +1 more source

Quantum-enabled optical large-baseline interferometry: applications, protocols and feasibility

Advances in Physics: X
Optical Very Long Baseline Interferometry (VLBI) offers the potential for unprecedented angular resolution in both astronomical imaging and geodesy measurements.
Zixin Huang, Oleg Titov, Mikołaj K. Schmidt, Benjamin Pope, Gavin K. Brennen, Daniel K. L. Oi, Pieter Kok   +6 more
doaj   +1 more source

Precessing Jet in the High-Redshift Blazar J0017+8135

Galaxies, 2016
The prominent flat-spectrum radio quasar J0017+8135 (S5 0014+81) at z = 3.366 is one of the most luminous active galactic nuclei (AGN) known. Its milliarcsecond-scale radio jet structure has been studied with very long baseline interferometry (VLBI ...
Kristóf Rozgonyi, Sándor Frey
doaj   +1 more source

Ionospheric Data Fusion With GNSS, GNSS‐RO and Satellite Altimetry Based on Machine Learning

Journal of Geophysical Research: Machine Learning and Computation, Volume 3, Issue 3, June 2026.
Abstract Global Ionospheric Maps (GIMs) are essential in Global Navigation Satellite System (GNSS) applications, particularly for correcting ionospheric delays in single‐frequency positioning. GIMs are mainly derived from dual‐frequency GNSS observations, but the uneven distribution of ground stations—sparse over oceans—reduces accuracy in these ...
Marcel Iten, Shuyin Mao, Benedikt Soja
wiley   +1 more source

Very Long Baseline Interferometry Search for Nuclear Radio Continuum Emission in the Barred Spiral Galaxy NGC 7479

The Astronomical Journal
We have obtained very high angular resolution (a few milliarcseconds or sub-parsec-scale) Very Long Baseline Array (VLBA) and European Very Long Baseline Interferometry Network (EVN) radio continuum images of the nucleus in the barred spiral galaxy NGC ...
Seppo Laine, Emmanuel Momjian, Emilia Järvelä, Thomas P. Krichbaum, S. Komossa, Travis C. Fischer, Thomas G. Pannuti   +6 more
doaj   +1 more source

Ray tracing-based delay model for compensating gravitational deformations of VLBI radio telescopes

Journal of Geodetic Science, 2022
The precision and the reliability of very long baseline interferometry (VLBI) depend on several factors. Apart from fabrication discrepancies or meteorological effects, gravity-induced deformations of the receiving unit of VLBI radio telescopes are ...
Lösler Michael, Eschelbach Cornelia, Greiwe Ansgar, Brechtken Rainer, Plötz Christian, Kronschnabl Gerhard, Neidhardt Alexander   +6 more
doaj   +1 more source

Frequency Standard Contributions to Limitations on the Signal‐to‐Noise Ratio in Very Long Baseline Interferometric Observations

Radio Science, Volume 61, Issue 6, June 2026.
Abstract Since its observation in 2019, the first image of a super‐massive black hole using Very Long Baseline Interferometry (VLBI) with an Earth‐scale baseline has generated much scientific and public interest. Work is now underway to extend the baseline into space to obtain higher image resolution.
E. A. Burt, T. A. Ely, G. C. Bower, T. J. W. Lazio, M. Anderson, S. Hernandez   +5 more
wiley   +1 more source