Earth Rotation Observed by Very Long Baseline Interferometry and Ring Laser

2009 ◽  
pp. 1499-1517
Author(s):  
P. J. Mendes Cerveira ◽  
J. Boehm ◽  
H. Schuh ◽  
T. Kluegel ◽  
A. Velikoseltsev ◽  
...  
Keyword(s):  
Earth Rotation ◽  
Ring Laser ◽  
Very Long Baseline Interferometry ◽  
Long Baseline

Earth Rotation Observed by Very Long Baseline Interferometry and Ring Laser

2009 ◽  
Vol 166 (8-9) ◽  
pp. 1499-1517 ◽  
Author(s):  
P. J. Mendes Cerveira ◽  
J. Boehm ◽  
H. Schuh ◽  
T. Kluegel ◽  
A. Velikoseltsev ◽  
...  
Keyword(s):  
Earth Rotation ◽  
Ring Laser ◽  
Very Long Baseline Interferometry ◽  
Long Baseline

EARTH ROTATION PARAMETERS FROM VERY LONG BASELINE INTERFEROMETRY AND RINGLASER OBSERVABLES

2010 ◽  
pp. 155-165 ◽  
Author(s):  
P. J. MENDES CERVEIRA ◽  
H. SPICAKOVA ◽  
H. SCHUH ◽  
T. KLUEGEL ◽  
U. SCHREIBER ◽  
...  
Keyword(s):  
Earth Rotation ◽  
Very Long Baseline Interferometry ◽  
Long Baseline ◽  
Earth Rotation Parameters ◽  
Rotation Parameters

Daily Earth rotation determinations from IRIS very long baseline interferometry

Nature ◽  
1985 ◽  
Vol 316 (6027) ◽  
pp. 424-427 ◽  
Author(s):  
D. S. Robertson ◽  
W. E. Carter ◽  
J. Campbell ◽  
H. Schuh
Keyword(s):  
Earth Rotation ◽  
Very Long Baseline Interferometry ◽  
Long Baseline

scholarly journals Monitoring UT1 from astro-geodetic techniques at the EOP Center of the IERS

2009 ◽  
Vol 5 (H15) ◽  
pp. 207-208
Author(s):  
D. Gambis ◽  
C. Bizouard
Keyword(s):  
Time Scales ◽  
Orbit Determination ◽  
Earth Rotation ◽  
Reference Frames ◽  
Very Long Baseline Interferometry ◽  
Space Geodesy ◽  
Earth Orientation ◽  
Long Baseline ◽  
The Earth ◽  
Fluid Layers

AbstractMonitoring the Earth rotation is essential in various domains linked to reference frames firstly with applications in orbit determination, space geodesy or Astronomy. Secondly for geophysical studies where are involved mass motions within the different external fluid layers, atmosphere, hydrosphere, core and mantle of the earth, this on time scales ranging from a few hours to decades. The Earth Orientation Centre of the IERS is continuously monitoring the earth orientation variations from results derived from the various astro-geodetic techniques. It has in particular the task of deriving an optimal combined series of UT1 which is now based mainly on Very Long Baseline Interferometry (VLBI) with some contribution of LOD derived from GPS. We give here a brief summary concerning the contribution of the various techniques to UT1 and in aprticular how the use of LOD derived from GPS can improve the combination. More details are available in Gambis (2004) and Bizouard and Gambis (2009) and the website http://hpiers.obspm.fr/eop-pc/

scholarly journals Commision 19: Earth Rotation (Rotation de la Terre)

1991 ◽  
Vol 21 (1) ◽  
pp. 169-186
Keyword(s):  
Reference Frame ◽  
Earth Rotation ◽  
Very Long Baseline Interferometry ◽  
International Association ◽  
High Accuracy ◽  
Terrestrial Reference Frame ◽  
International Earth Rotation Service ◽  
Long Baseline ◽  
Compact Sources ◽  
Celestial Reference Frame

The period has been marked by the start of the new International Earth Rotation Service (IERS), which benefits from a tight cooperation between astronomers, geodesists, and specialists in satellite geodesy, as well as meteorologists. The scope of the IERS covers not only the Earth’s rotation per se, but also the conventional terrestrial reference frame, of direct interest to the International Association of Geodesy, and a high accuracy (0.001”) celestial reference frame based on extragalactic compact sources observed in Very Long Baseline Interferometry. The IERS conventional celestial reference frame is consistent with the FK5 within the uncertainties of the latter (0.04”). The IERS Standards (1989) which contain the current best estimates of astronomical models and constants are used in many fields of astronomy and geodesy.

Masers as probes of the gas dynamics close to forming high-mass stars

2017 ◽  
Vol 13 (S336) ◽  
pp. 201-206 ◽  
Author(s):  
Luca Moscadelli ◽  
Alberto Sanna ◽  
Ciriaco Goddi
Keyword(s):  
Gas Dynamics ◽  
Very Long Baseline Interferometry ◽  
High Mass ◽  
Powerful Technique ◽  
Long Baseline ◽  
Vlbi Observations ◽  
Massive Forming ◽  
Typical Distances ◽  
New Generation ◽  
Better Than

AbstractImaging the inner few 1000 AU around massive forming stars, at typical distances of several kpc, requires angular resolutions of better than 0″.1. Very Long Baseline Interferometry (VLBI) observations of interstellar molecular masers probe scales as small as a few AU, whereas (new-generation) centimeter and millimeter interferometers allow us to map scales of the order of a few 100 AU. Combining these informations all together, it presently provides the most powerful technique to trace the complex gas motions in the proto-stellar environment. In this work, we review a few compelling examples of this technique and summarize our findings.

scholarly journals A Tri-Band Cooled Receiver for Geodetic VLBI

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2662
Author(s):  
José A. López-Pérez ◽  
Félix Tercero-Martínez ◽  
José M. Serna-Puente ◽  
Beatriz Vaquero-Jiménez ◽  
María Patino-Esteban ◽  
...  
Keyword(s):  
Very Long Baseline Interferometry ◽  
Low Noise ◽  
Cryogenic Temperatures ◽  
Geospatial Information ◽  
Receiver Noise ◽  
Geodetic Vlbi ◽  
Long Baseline ◽  
Front End ◽  
X Band ◽  
Santa Maria

This paper shows a simultaneous tri-band (S: 2.2–2.7 GHz, X: 7.5–9 GHz and Ka: 28–33 GHz) low-noise cryogenic receiver for geodetic Very Long Baseline Interferometry (geo-VLBI) which has been developed at Yebes Observatory laboratories in Spain. A special feature is that the whole receiver front-end is fully coolable down to cryogenic temperatures to minimize receiver noise. It was installed in the first radio telescope of the Red Atlántica de Estaciones Geodinámicas y Espaciales (RAEGE) project, which is located in Yebes Observatory, in the frame of the VLBI Global Observing System (VGOS). After this, the receiver was borrowed by the Norwegian Mapping Autorithy (NMA) for the commissioning of two VGOS radiotelescopes in Svalbard (Norway). A second identical receiver was built for the Ishioka VGOS station of the Geospatial Information Authority (GSI) of Japan, and a third one for the second RAEGE VGOS station, located in Santa María (Açores Archipelago, Portugal). The average receiver noise temperatures are 21, 23, and 25 Kelvin and the measured antenna efficiencies are 70%, 75%, and 60% in S-band, X-band, and Ka-band, respectively.

scholarly journals A radio parallax to the black hole X-ray binary MAXI J1820+070

2020 ◽  
Vol 493 (1) ◽  
pp. L81-L86 ◽  
Author(s):  
P Atri ◽  
J C A Miller-Jones ◽  
A Bahramian ◽  
R M Plotkin ◽  
A T Deller ◽  
...  
Keyword(s):  
Black Hole ◽  
Inclination Angle ◽  
Precise Measurement ◽  
Very Long Baseline Interferometry ◽  
X Ray ◽  
Long Baseline ◽  
Model Independent ◽  
Jet Velocity ◽  
Very Long Baseline Array

ABSTRACT Using the Very Long Baseline Array and the European Very Long Baseline Interferometry Network, we have made a precise measurement of the radio parallax of the black hole X-ray binary MAXI J1820+070, providing a model-independent distance to the source. Our parallax measurement of (0.348 ± 0.033) mas for MAXI J1820+070 translates to a distance of (2.96 ± 0.33) kpc. This distance implies that the source reached (15 ± 3) per cent of the Eddington luminosity at the peak of its outburst. Further, we use this distance to refine previous estimates of the jet inclination angle, jet velocity, and the mass of the black hole in MAXI J1820+070 to be (63 ± 3)°, (0.89 ± 0.09) c, and (9.2 ± 1.3) M⊙, respectively.

External atmospheric corrections in geodetic very-long-baseline interferometry

1999 ◽  
Vol 73 (7) ◽  
pp. 375-383 ◽  
Author(s):  
T. R. Emardson ◽  
G. Elgered ◽  
J. M. Johansson
Keyword(s):  
Very Long Baseline Interferometry ◽  
Long Baseline
Sign in / Sign up

Export Citation Format

Share Document