Results 11 to 20 of about 27,737 (204)

A Comparative Study of VTEC Estimates Derived From S/X VLBI and VGOS Observations

Space Weather
The ionosphere, which strongly varies in time and space, is one of the largest error sources for microwave measurements, if not accounted for accurately.
Arno Rüegg, Grzegorz Kłopotek, Benedikt Soja   +2 more
doaj   +2 more sources

Global Geodetic Observing System 2015–2018 [PDF]

Geodesy and Cartography, 2019
Global Geodetic Observing System (GGOS) was established in 2003 by the International Association of Geodesy (IAG) with the main goal to deepen understanding of the dynamic Earth system by quantifying human-induced Earth’s changes in space and time.
Krzysztof Sośnica, Jarosław Bosy
doaj   +1 more source

Precise VLBI/GNSS ties with micro-VLBI

, 2023
We present here a concept of measuring local ties between collocated GNSS and VLBI stations using the microwave technique that effectively transforms a GNSS receiver to an element of a VLBI network. This is achieved by modifying the signal chain that allows to transfer voltage of the GNSS antenna to a digitizer via a coaxial cable.
Petrov, Leonid, York, Johnathan, Skeens, Joe, Ji-Cathriner, Richard, Munton, David, Herrity, Kyle   +5 more
openaire   +2 more sources

Overview of the Observing System and Initial Scientific Accomplishments of the East Asian VLBI Network (EAVN)

Galaxies, 2022
The East Asian VLBI Network (EAVN) is an international VLBI facility in East Asia and is operated under mutual collaboration between East Asian countries, as well as part of Southeast Asian and European countries.
Kazunori Akiyama, Juan-Carlos Algaba, Tao An, Keiichi Asada, Kitiyanee Asanok, Do-Young Byun, Thanapol Chanapote, Wen Chen, Zhong Chen, Xiaopeng Cheng, James O. Chibueze, Ilje Cho, Se-Hyung Cho, Hyun-Soo Chung, Lang Cui, Yuzhu Cui, Akihiro Doi, Jian Dong, Kenta Fujisawa, Wei Gou, Wen Guo, Kazuhiro Hada, Yoshiaki Hagiwara, Tomoya Hirota, Jeffrey A. Hodgson, Mareki Honma, Hiroshi Imai, Phrudth Jaroenjittichai, Wu Jiang, Yongbin Jiang, Yongchen Jiang, Takaaki Jike, Dong-Kyu Jung, Taehyun Jung, Noriyuki Kawaguchi, Dong-Jin Kim, Hyo-Ryoung Kim, Jaeheon Kim, Jeong-Sook Kim, Kee-Tae Kim, Soon-Wook Kim, Motoki Kino, Hideyuki Kobayashi, Shoko Koyama, Busaba H. Kramer, Jee-Won Lee, Jeong Ae Lee, Sang-Sung Lee, Sang Won Lee, Bin Li, Guanghui Li, Xiaofei Li, Zhixuan Li, Qinghui Liu, Xiang Liu, Ru-Sen Lu, Kazuhito Motogi, Masanori Nakamura, Kotaro Niinuma, Chungsik Oh, Hongjong Oh, Junghwan Oh, Se-Jin Oh, Tomoaki Oyama, Jongho Park, Saran Poshyachinda, Hyunwook Ro, Duk-Gyoo Roh, Wiphu Rujopakarn, Nobuyuki Sakai, Satoko Sawada-Satoh, Zhi-Qiang Shen, Katsunori M. Shibata, Bong Won Sohn, Boonrucksar Soonthornthum, Koichiro Sugiyama, Yunxia Sun, Mieko Takamura, Yoshihiro Tanabe, Fumie Tazaki, Sascha Trippe, Kiyoaki Wajima, Jinqing Wang, Na Wang, Shiqiang Wang, Xuezheng Wang, Bo Xia, Shuangjing Xu, Hao Yan, Wenjun Yang, Jae-Hwan Yeom, Kunwoo Yi, Sang-Oh Yi, Yoshinori Yonekura, Hasu Yoon, Linfeng Yu, Jianping Yuan, Youngjoo Yun, Bo Zhang, Hua Zhang, Yingkang Zhang, Guang-Yao Zhao, Rongbing Zhao, Weiye Zhong, on behalf of the East Asian VLBI Network Collaboration   +104 more
doaj   +1 more source

Ray tracing-based delay model for compensating gravitational deformations of VLBI radio telescopes

Journal of Geodetic Science, 2022
The precision and the reliability of very long baseline interferometry (VLBI) depend on several factors. Apart from fabrication discrepancies or meteorological effects, gravity-induced deformations of the receiving unit of VLBI radio telescopes are ...
Lösler Michael, Eschelbach Cornelia, Greiwe Ansgar, Brechtken Rainer, Plötz Christian, Kronschnabl Gerhard, Neidhardt Alexander   +6 more
doaj   +1 more source

Rotation of Earth and determination of Earth orientation parameters [PDF]

Geodetski Glasnik, 2015
Earth's rotation and elements of the Earth's orientation, with emphasis on the determination of the parameters of the Earth's orientation were described.
Mirko Borisov, Miro Govedarica, Maja Orihan   +2 more
doaj   +1 more source

Comparison of VLBI and GNSS common view for time transfer

International Journal of Metrology and Quality Engineering, 2019
With the rapid development of optical clock, the stability and system uncertainty of optical clocks has reached a 1.0e–18 level. Optical clocks will likely constitute the next generation of time-frequency standards for redefining the SI second.
Wang Pingli, Wang Guangli, Gao Yuping, Cai Hongbing, Liu Na   +4 more
doaj   +1 more source

Japanese VLBI Project — Vera [PDF]

Symposium - International Astronomical Union, 1988
The Japanese VLBI project VERA (VLBI for the Earth Rotation study and Astrometry) is being designed. It will be dedicated to regular monitoring of the Earth's rotation and astrometry. VERA will be composed of two antennas spanning about 2300km and a correlator of multi-station capability. The diameters of the antennas are 35m and 15m.
Mitsumi Fujishita, Tadayoshi Hara
openaire   +1 more source

GPU-Based Parallel Implementation of VLBI Correlator for Deep Space Exploration System

Remote Sensing, 2021
Very Long Baseline Interferometry (VLBI) solution can yield accurate information of angular position, and has been successfully used in the field of deep space exploration, such as astrophysics, imaging, detector positioning, and so on.
Fan Zhang, Chenxi Zhao, Songtao Han, Fei Ma, Deliang Xiang   +4 more
doaj   +1 more source

Solving the polarization problem in ALMA-VLBI observations [PDF]

, 2014
The Atacama Large mm-submm Array (ALMA) is, by far, the most sensitive mm/submm telescope in the World. The ALMA Phasing Project (APP) will allow us to phase-up all the ALMA antennas and use them as one single VLBI station.
Alef, W., Conway, J., Lindqvist, M., Marti-Vidal, I., Roy, A., Zensus, A. J.   +5 more
core   +1 more source