Results 1 to 10 of about 27,177 (193)

Optical frequency comb integration in radio telescopes: advancing signal generation and phase calibration [PDF]

Light: Science & Applications
Very long baseline interferometry (VLBI) enables high-angular-resolution observations in astronomy and geodesy by synthesizing a virtual telescope with baselines spanning hundreds to thousands of kilometres. Achieving high instrumental phase stability in
Minji Hyun, Changmin Ahn, Junyong Choi, Jihoon Baek, Woosong Jeong, Do-Heung Je, Do-Young Byun, Jan Wagner, Myoung-Sun Heo, Taehyun Jung, Jungwon Kim   +10 more
doaj   +2 more sources

Radio Astronomical Antennas in the Central African Region to Improve the Sampling Function of the VLBI Network in the SKA Era? [PDF]

Sensors, 2022
On the African continent, South Africa has world-class astronomical facilities for advanced radio astronomy research. With the advent of the Square Kilometre Array project in South Africa (SA SKA), six countries in Africa (SA SKA partner countries) have ...
Marcellin Atemkeng, Patrice Okouma, Eric Maina, Roger Ianjamasimanana, Serges Zambou   +4 more
doaj   +2 more sources

The Celestial Frame and the Weighting of the Celestial Pole Offsets in the Computation of VLBI-Based Corrections for the Main Lunisolar Nutation Terms [PDF]

Sensors, 2021
Very long baseline interferometry (VLBI) is the only technique in space geodesy that can determine directly the celestial pole offsets (CPO). In this paper, we make use of the CPO derived from global VLBI solutions to estimate empirical corrections to ...
Víctor Puente, Marta Folgueira
doaj   +2 more sources

VLBI Type Experimental Observation of GPS [PDF]

Journal of Astronomy and Space Sciences, 2010
As a preparatory study for Global Positioning System-Very Long Baseline Interferometry (GPS-VLBI) hybrid system, we examined if VLBI type observation of the GPS signal is realizable through a test experiment.
Younghee Kwak, Tetsuro Kondo, Jun Amagai, Tadahiro Gotoh, Tetsuo Sasao, Jungho Cho, Tuhwan Kim   +6 more
doaj   +1 more source

The Role of Spatial Gradient on Vertical Total Electron Content Extraction From Geodetic Very Long Baseline Interferometry Observation: Case Study CONT08 to CONT17‐L1

Space Weather, 2021
Geodetic very long baseline interferometry (VLBI) observations are carried out, with the legacy system, using two well‐separated frequency bands in order to determine first‐order ionospheric delay corrections corresponding to the combined effect of total
Hossein Etemadfard, Robert Heinkelmann, Masoud Mashhadi Hossainali, Harald Schuh   +3 more
doaj   +1 more source

HINOTORI and Its Perspectives in the Black-Hole Jet Study

Galaxies, 2023
Simultaneous multi-band very long baseline interferometry (VLBI) observations at millimeter wavelengths have huge potential for various science cases.
Toshihisa Tsutsumi, Kotaro Niinuma, Hiroshi Imai, Ryoko Amari, Yusuke Shimizu, Hideo Ogawa, Atsushi Nishimura, Chieko Miyazawa, Tomoaki Oyama, Hiroyuki Kaneko, Keisuke Nakashima, Satoko Sawada-Satoh, Takahiro Aoki   +12 more
doaj   +1 more source

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

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

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

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