Searched for: subject:"techniques%5C%3A%5C+interferometric"
(1 - 8 of 8)
document
Naghibzadeh, S. (author), van der Veen, A.J. (author)
Image formation in radio astronomy is a large-scale inverse problem that is inherently illposed. We present a general algorithmic framework based on a Bayesian-inspired regularized maximum likelihood formulation of the radio astronomical imaging problem with a focus on diffuse emission recovery from limited noisy correlation data. The...
journal article 2018
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Litvinov, D.A. (author), Bach, U. (author), Bartel, N. (author), Belousov, K.G. (author), Bietenholz, M. (author), Biriukov, A.V. (author), Cimo, G (author), Duev, D. A. (author), Gurvits, L. (author), Gusev, A.V. (author), Haas, R (author), Kauts, V.L. (author), Kanevsky, B.Z. (author), Kovalenko, A.V. (author), Kronschnabl, G (author), Kulagin, V.V. (author), Lindqvist, Maria (author), Molera Calves, G (author), Neidhardt, A. (author), Plotz, C. (author), Pogrebenko, S. V. (author), Porayko, N.K. (author), Rudenko, V.N. (author), Sokolovsky, K. V. (author), Smirnov, A.I. (author), Stepanyants, V.A. (author), Yang, J. (author), Zakhvatkin, M.V. (author)
A test of a cornerstone of general relativity, the gravitational redshift effect, is currently being conducted with the RadioAstron spacecraft, which is on a highly eccentric orbit around Earth. Using ground radio telescopes to record the spacecraft signal, synchronized to its ultra-stable on-board H-maser, we can probe the varying flow of time...
conference paper 2016
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Duev, D.A. (author), Zakhvatkin, M.V. (author), Stepanyants, V.A. (author), Molera Calvés, G. (author), Pogrebenko, S.V. (author), Gurvits, L.I. (author), Cimò, G. (author), Bocanegra Bahamón, T.M. (author)
Context. The accuracy of orbit determination has a strong impact on the scientific output of the Space VLBI mission RadioAstron. Aims. The aim of this work is to improve the RadioAstron orbit reconstruction by means of sophisticated dynamical modelling of its motion in combination with multi-station Doppler tracking of the RadioAstron spacecraft...
journal article 2015
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Molera Calvés, G. (author), Pogrebenko, S.V. (author), Cimò, G. (author), Duev, D.A. (author), Bocanegra-Bahamón, T.M. (author), Wagner, J.F. (author), Kallunki, J. (author), De Vicente, P. (author), Kronschnabl, G. (author), Haas, R. (author), Quick, J. (author), Maccaferri, G. (author), Colucci, G. (author), Wang, W.H. (author), Yang, W.J. (author), Hao, L.F. (author)
Aims. The phase scintillation of the European Space Agency’s Venus Express (VEX) spacecraft telemetry signal was observed at X-band (? = 3.6 cm) with a number of radio telescopes of the European Very Long Baseline Interferometry (VLBI) Network in the period 2009–2013. Methods. We found a phase fluctuation spectrum along the Venus orbit with a...
journal article 2014
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Cao, H.M. (author), Frey, S. (author), Gurvits, L. (author), Yang, J. (author), Hong, X.Y. (author), Paragi, Z. (author), Deller, A.T. (author), Ivezic, Z. (author)
A patch of sky in the SDSS Stripe 82 was observed at 1.6 GHz with Very Long Baseline Interferometry (VLBI) using the European VLBI Network (EVN). The data were correlated at the EVN software correlator at JIVE (SFXC). There are fifteen known mJy/sub-mJy radio sources in the target field defined by the primary beam size of a typical 30-m class...
journal article 2014
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Duev, D.A. (author), Molera Calvés, G. (author), Pogrebenko, S.V. (author), Gurvits, L.I. (author), Cimó, G. (author), Bocanegra Bahamon, T. (author)
Aims. We present the results of several multi-station Very Long Baseline Interferometry (VLBI) experiments conducted with the ESA spacecraft Venus Express as a target. To determine the true capabilities of VLBI tracking for future planetary missions in the solar system, it is necessary to demonstrate the accuracy of the method for existing...
conference paper 2012
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Intema, H.T. (author), Van der Tol, S. (author), Cotton, W.D. (author), Cohen, A.S. (author), Van Bemmel, I.M. (author), Röttgering, H.J.A. (author)
Calibration of radio interferometric observations becomes increasingly difficult towards lower frequencies. Below ?300 MHz, spatially variant refractions and propagation delays of radio waves traveling through the ionosphere cause phase rotations that can vary significantly with time, viewing direction and antenna location. In this article we...
journal article 2009
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Spronck, J.F.P. (author), Pereira, S.F. (author)
We show a fundamental limitation of multi-axial beam combiners in nulling interferometry. The longitudinal electric field induced by the focusing optics can drastically limit the performance of such a nulling interferometer. We further analyze the filtering capabilities of a single-mode optical fiber with respect to that longitudinal field.
journal article 2009
Searched for: subject:"techniques%5C%3A%5C+interferometric"
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