Results 81 to 90 of about 2,072 (163)

Evaluating the feasibility of short-integration scans based on the 2022 VGOS-R&D program [PDF]

, 2023
In this work, we report on activities focusing on improving the observation strategy of the Very Long Baseline Interferometry (VLBI) Global Observing System (VGOS).
Krasna, Hana, Schartner, Matthias, Xu, Minghui, Petrachenko, Bill, Titus, Mike, Barrett, John, Hoak, Dan, Soja, Benedikt, Mondal, Dhiman   +8 more
core   +1 more source

Probing atmospheric turbulence with VLBI residuals: when theory meets observations

Earth, Planets and Space
Geodetic very long baseline interferometry (VLBI) is affected by stochastic fluctuations in atmospheric water vapor, which degrade delay measurements and limit the precision of derived geodetic parameters.
Gaël Kermarrec, Matthias Schartner
doaj   +1 more source

Optimal distribution of VLBI transmitters in the Galileo space segment for frame ties. [PDF]

Earth Planets Space, 2023
Wolf H, Böhm J.
europepmc   +1 more source

The Australian mixed-mode observing program. [PDF]

J Geod, 2022
McCallum L, Chin Chuan L, Krásná H, McCallum J, Böhm J, McCarthy T, Gruber J, Schartner M, Quick J, Rogers A.   +9 more
europepmc   +1 more source

A Comparative Survey of Adaptive Codec Solutions for VoIP over Multirate WLANs: A Capacity versus Quality Performance Trade-Off

EURASIP Journal on Wireless Communications and Networking, 2011
In multi-rate WLANs, users can suffer transmission rate changes due to the link adaptation mechanism. This results in a variable capacity channel, which is very hostile for VoIP and can cause serious quality of service (QoS) degradation in all active ...
Sfairopoulou A, Bellalta B, Macian C, Oliver M   +3 more
doaj  

A Tri-band Low-noise Cryogenic Receiver for Geodetic VLBI Observations with VGOS Radio Telescopes

, 2019
This paper shows the development of 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 by the technical staff of Yebes ...
J. López-Pérez, F. Tercero-Martínez, J. Serna-Puente, B. Vaquero-Jiménez, M. Patino-Esteban, P. García-Carreño, J. González-García, Ó. García-Pérez, Francisco J. Beltrán-Martínez, C. Albo-Castaño, J. D. Gallego-Puyol, I. López-Fernández, C. Díez-González, I. Malo-Gómez, L. Barbas-Calvo, Pablo de Vicente-Abad, J. López-Fernández   +16 more
semanticscholar   +1 more source

Cross-polarization Gain Calibration of VGOS Antennas

Antennas of the VLBI Global Observing System (VGOS) observe dual linear polarization. Calibration of the complex gain differences between the two polarizers of each antenna is neccesary in order to form Stokes I and to maximize the signal-to-noise ratio ...
Modiri, Sadegh, Schartner, Matthias, Gonzalez Garcia, Javier, Ezequiel Albentosa, Bernhart, Simone, Böhm, Johannes; orcid:, Nothnagel, Axel Gerhard, Pérez‐Díez, Victor, Xu, Minghui, Marti-Vidal, Ivan, Savolainen, Tuomas, Varenius, Eskil; orcid:, Soja, Benedikt; orcid:, Cheung, Chi (Teddy); orcid:0000-0002-4377-0174, Jaron, Frederic Felix Daniel; orcid:   +14 more
core   +4 more sources

Probing a southern hemisphere VLBI Intensive baseline configuration for UT1 determination. [PDF]

Earth Planets Space, 2022
Böhm S, Böhm J, Gruber J, Kern L, McCallum J, McCallum L, McCarthy T, Quick J, Schartner M.   +8 more
europepmc   +1 more source

The Current and Future Performance of VGOS [PDF]

, 2023
In this work we investigate the performance\ua0of the 24-hour VGOS sessions observed in 2019–2021.\ua0We look at the station positions and the Earth Orientation\ua0parameters (EOP), and we compare them with\ua0the results from the legacy S/X VLBI ...
Haas, R\ufcdiger, Nilsson, Tobias, Varenius, Eskil   +2 more
core  

VLBI measurement of the vector baseline between geodetic antennas at Kokee Park Geophysical Observatory, Hawaii. [PDF]

J Geod, 2021
Niell AE, Barrett JP, Cappallo RJ, Corey BE, Elosegui P, Mondal D, Rajagopalan G, Ruszczyk CA, Titus MA.   +8 more
europepmc   +1 more source