Results 61 to 70 of about 27,573 (245)
Data Handling within the International VLBI Service
Data Science Journal, 2013 The International VLBI Service for Geodesy and Astrometry (IVS) is a globally operating service that coordinates and performs Very Long Baseline Interferometry (VLBI) activities through its constituent components.
Dirk Behrend
doaj +1 more source
A New Very Long Baseline Interferometry Method Based on the Uplink Signal
IEEE Access, 2020 Very long baseline interferometry (VLBI) is widely used for astronomical observations and navigation of deep space receivers. To solve the problems of the downlink signal being excessively weak to be received and the excessively large acquisition time, a
Linshan Xue, Weiren Wu, Xue Li
doaj +1 more source
The Short-Arc Precise Orbit Determination of GEO Satellites Using VLBI and Transfer Ranging
Remote Sensing, 2022 It is important for a geostationary Earth orbit (GEO) satellite to rapidly recover its orbit after a maneuver with short-arc precise orbit determination (POD).
Kai Nan +5 more
doaj +1 more source
The Gaia reference frame for bright sources examined using VLBI observations of radio stars [PDF]
Astronomy & Astrophysics, 2019 Context. Positions and proper motions of Gaia sources are expressed in a reference frame that ideally should be non-rotating relative to distant extragalactic objects, coincident with the International Celestial Reference System (ICRS), and consistent ...
L. Lindegren
semanticscholar +1 more source
Earth, Planets and Space, 2023 VLBI simulation studies are carried out to investigate the impact of any proposed station or strategy on the geodetic parameters, such as Earth Orientation Parameters (EOP) and Terrestrial Reference Frame (TRF). In general, such studies are performed for
Sujata Dhar +5 more
doaj +1 more source
High-fidelity wideband VLBI polarimetry
, 2023 We will discuss about wideband and multiband VLBI observations taken with linear-polarization feeds (the simplest hardware polarimetry for wide bands), and how these observations can be calibrated and fringe-fitted with special software, in order to ...
Martí-Vidal, Iván
core +1 more source
International Astronomical Union Colloquium, 1990 AbstractVLBI observations using a satellite in earth orbit and ground antennas in Japan and Australia were conducted in 1986, 1987, and 1988. Sources were detected on space-ground baselines at both observing frequencies: 2.3 and 15 GHz. The coherence on space-ground baselines for 340 s was 90% at 2.3 GHz and 76% at 15 GHz.
openaire +1 more source
Calibration of ALMA as a Phased Array. ALMA Observations During the 2017 VLBI Campaign [PDF]
Publications of the Astronomical Society of the Pacific, 2019 We present a detailed description of the special procedures for calibration and quality assurance of Atacama Large Millimeter/submillimeter Array (ALMA) observations in Very Long Baseline Interferometry (VLBI) mode.
C. Goddi +16 more
semanticscholar +1 more source
Imaging black holes and jets with a VLBI array including multiple space-based telescopes [PDF]
, 2019 Very long baseline interferometry (VLBI) from the ground at millimeter wavelengths can resolve the black hole shadow around two supermassive black holes, Sagittarius A∗ and M87. The addition of modest telescopes in space would allow the combined array to
V. Fish, M. Shea, K. Akiyama
semanticscholar +1 more source
Metrics and Motivations for Earth–Space VLBI: Time-resolving Sgr A* with the Event Horizon Telescope [PDF]
Astrophysical Journal, 2019 Very-long-baseline interferometry (VLBI) at frequencies above 230 GHz with Earth-diameter baselines gives spatial resolution finer than the ∼50 μas “shadow” of the supermassive black hole at the Galactic Center, Sagittarius A* (Sgr A*).
D. Palumbo +4 more
semanticscholar +1 more source