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We revisit the "Cluster-Cluster" or multi-view Very-Long-Baseline-Interferometry (VLBI) technique from the perspective of its synergy with the multi-beam features inherent in the Australian Square Kilometer Array Pathfinder (ASKAP)and its…

Instrumentation and Methods for Astrophysics · Physics 2009-09-28 M. J. Rioja , R. Dodson , R. W. Porcas , D. Ferris , J. Reynolds , T. Sasao , R. T. Schilizzi

We present the principal astrometric results of the very-long-baseline interferometry (VLBI) program undertaken in support of the Gravity Probe B (GP-B) relativity mission. VLBI observations of the GP-B guide star, the RS CVn binary IM…

Instrumentation and Methods for Astrophysics · Physics 2015-06-04 M. I. Ratner , N. Bartel , M. F. Bietenholz , D. E. Lebach , J. -F. Lestrade , R. R. Ransom , I. I. Shapiro

Wide-field surveys are a commonly-used method for studying thousands of objects simultaneously, to investigate, e.g., the joint evolution of star-forming galaxies and active galactic nuclei. VLBI observations can yield valuable input to…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Enno Middelberg , Adam Deller , John Morgan , Helge Rottmann , Walter Alef , Steven Tingay , Ray Norris , Uwe Bach , Walter Brisken , Emil Lenc

Two radio-science instruments have included into the Luna-Glob and Luna-Resource projects in the frame of Russian Luna exploration program: the lander's radio beacon and the orbiter's receiver. Three types of experiments are planned:…

Instrumentation and Methods for Astrophysics · Physics 2015-12-16 V. D. Gromov , A. S. Kosov

Very long baseline interferometry (VLBI) technique allows us to determine positions of thousands of radio sources using the absolute astrometry approach. I have investigated the impact of a selection of observing frequencies in a range from…

Instrumentation and Methods for Astrophysics · Physics 2024-05-14 Leonid Petrov

Differential phase observations with a near-IR interferometer offer a way to obtain spectra of extrasolar planets. The method makes use of the wavelength dependence of the interferometer phase of the planet/star system, which depends both…

Astrophysics · Physics 2015-06-24 Viki Joergens , Andreas Quirrenbach

Recent discoveries of dispersed, non-periodic impulsive radio signals with single-dish radio telescopes have sparked significant interest in exploring the relatively uncharted space of fast transient radio signals. Here we describe V-FASTR,…

Instrumentation and Methods for Astrophysics · Physics 2015-05-28 Randall B. Wayth , Walter F. Brisken , Adam T. Deller , Walid A. Majid , David R. Thompson , Steven J. Tingay , Kiri L. Wagstaff

The radial velocity (RV) method, also known as Doppler spectroscopy, is a powerful technique for exoplanet discovery and characterization. In recent years, progress has been made thanks to the improvements in the quality of spectra from new…

Earth and Planetary Astrophysics · Physics 2026-01-06 Joseph Salzer , Jessi Cisewski-Kehe , Eric B. Ford , Lily L. Zhao

We discuss the unique opportunities for maser astrometry with the inclusion of the Square Kilometre Array (SKA) in Very Long Baseline Interferometry (VLBI) networks. The first phase of the SKA will enable observations of hydroxyl and…

We present a new method of time-dependent instrumental polarization calibration for Very Long Baseline Interferometry (VLBI). This method has been implemented in the recently developed polarization calibration pipeline GPCAL. Instrumental…

Instrumentation and Methods for Astrophysics · Physics 2023-10-06 Jongho Park , Keiichi Asada , Do-Young Byun

Very long baseline interferometry (VLBI) is a radio-astronomical technique in which the correlated signal from various baselines is combined into an image of highest angular resolution. Due to sparsity of the measurements, this imaging…

Instrumentation and Methods for Astrophysics · Physics 2023-03-29 Hendrik Müller , Andrei Lobanov

The arrival of the Square Kilometer Array (SKA) will revitalise all aspects of Very Long Baseline Interferometry (VLBI) astronomy at the lower frequencies. In the last decade there have been huge strides towards routinely achieving high…

Instrumentation and Methods for Astrophysics · Physics 2017-02-15 Maria J. Rioja , Richard Dodson , Gabor Orosz , Hiroshi Imai , Sandor Frey

By linking widely separated radio dishes, the technique of very long baseline interferometry (VLBI) can greatly enhance angular resolution in radio astronomy. However, at any given moment, a VLBI array only sparsely samples the information…

We present computer simulations of interferometric imaging with the Very Large Telescope Interferometer (VLTI) of the European Southern Observatory (ESO) and the Astronomical MultiBEam Recombiner (AMBER) phase-closure instrument. These…

Astrophysics · Physics 2015-06-24 F. Przygodda , T. Bloecker , K. -H. Hofmann , G. Weigelt

We present a new technique for obtaining model fittings to VLBI images of astrophysical jets. The method minimizes a performance function proportional to the sum of the squared difference between the model and observed images. The model…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Anderson Caproni , Hektor Monteiro , Zulema Abraham , Danilo. M. Teixeira , Rafael T. Toffoli

In this paper, a multistatic Doppler sensing system is proposed for the drone tracking via downlink Long-Term Evolution (LTE) signals. Specifically, the LTE base stations (BSs) are exploited as signal illuminators, and three passive sensing…

Signal Processing · Electrical Eng. & Systems 2025-10-01 Chenqing Ji , Qionghui Liu , Jiahong Liu , Chao Yu , Yifei Sun , Rui Wang , Fan Liu

With the establishment of the AUT University 12m radio telescope at Warkworth, New Zealand has now become a part of the international Very Long Baseline Interferometry (VLBI) community. A major product of VLBI observations are images in the…

Instrumentation and Methods for Astrophysics · Physics 2011-10-26 Stuart Weston , Tim Natusch , Sergei Gulyaev

To investigate the internal structure of the magnetopause with spacecraft data, it is crucial to be able to determine its normal direction and to convert the measured time series into spatial profiles. We propose here a new…

Earth and Planetary Astrophysics · Physics 2015-06-15 Nicolas Dorville , Gérard Belmont , Laurence Rezeau , Nicolas Aunai , Alessandro Retinò

Results of VLBI and GPS observations were analyzed with goal to investigate differences in observed baseline length derived from both techniques. VLBI coordinates for European stations were obtained from processing of all available…

Geophysics · Physics 2011-02-04 Zinovy Malkin , Natalia Panafidina , Elena Skurikhina

We report multi-epoch Very Long Baseline Interferometry (VLBI) study of the innermost jet of 3C 84. We carried out 14-epoch VLBI observations during 2006-2009 with the Japanese VLBI Network (JVN) and the VLBI Exploration of Radio Astrometry…

Cosmology and Nongalactic Astrophysics · Physics 2010-06-14 H. Nagai , K. Suzuki , K. Asada , M. Kino , S. Kameno , A. Doi , M. Inoue , U. Bach