Results 21 to 30 of about 9,456 (175)

Modelling Very Long Baseline Interferometry (VLBI) observations

Journal of Geodesy and Geoinformation, 2012
Bu çalışmanın temel amacı Çok Uzun Baz Enterferometrisi VLBI sinyal gecikme modelinin teorik detaylarını Uluslararası Yer Dönüklük ve Referans Sistemleri Servisi IERS 2010 Konvansiyonları temelinde sunmaktır. Bu kapsamda sürekli parçalı lineer ofset CPWLO fonksiyonları ile gün‒içi zamansal çözünürlükte önceden belirlenmiş epoklarda, örneğin: Evrensel ...
Teke, K., Kayýkçi, E., Böhm, J., Schuh, H.   +3 more
openaire   +4 more sources

Fibre-optic delivery of time and frequency to VLBI station [PDF]

, 2017
The quality of Very Long Baseline Interferometry (VLBI) radio observations predominantly relies on precise and ultra-stable time and frequency (T&F) standards, usually hydrogen masers (HM), maintained locally at each VLBI station.
Ablewski, P., Binczewski, A., Bober, M., Buczek, Ł., Campbell, R. M., Ciuryło, R., Cygan, A., Kołodziej, J., Krehlik, P., Lipiński, M., Lisak, D., Marecki, A., Masłowski, P., Morzyński, P., Nawrocki, J., Nogaś, P., Pazderski, E., Pieczerak, J., Turza, K., Zawada, M., Śliwczyński, Ł.   +20 more
core   +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

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

Parsec-scale magnetic fields in Arp 220 [PDF]

, 2014
We present the first very-long-baseline interferometry (VLBI) detections of Zeeman splitting in another galaxy. We used Arecibo Observatory, the Green Bank Telescope, and the Very Long Baseline Array to perform dual-polarization observations of OH maser ...
Bower, Geoffrey C., Heiles, Carl, McBride, James, Robishaw, Timothy, Sarma, Anuj P.   +4 more
core   +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 matter content of the jet in M87: evidence for an electron-positron jet [PDF]

, 1996
Recent observations have allowed the geometry and kinematics of the M87 jet to be tightly constrained. We combine these constraints with historical Very Long Baseline Interferometry (VLBI) results and the theory of synchrotron self-absorbed radio cores ...
Celotti, A., Fabian, A. C., Rees, M. J., Reynolds, C. S.   +3 more
core   +4 more sources

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

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

Observing APOD with the AuScope VLBI Array

Sensors, 2018
The possibility to observe satellites with the geodetic Very Long Baseline Interferometry (VLBI) technique is vividly discussed in the geodetic community, particularly with regard to future co-location satellite missions.
Andreas Hellerschmied, Lucia McCallum, Jamie McCallum, Jing Sun, Johannes Böhm, Jianfeng Cao   +5 more
doaj   +1 more source