H
Hideki Ujihara
Researcher at National Institute of Information and Communications Technology
Publications - 22
Citations - 235
Hideki Ujihara is an academic researcher from National Institute of Information and Communications Technology. The author has contributed to research in topics: Very-long-baseline interferometry & Wideband. The author has an hindex of 6, co-authored 22 publications receiving 204 citations.
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Journal ArticleDOI
First Fringe Detection with VERA's Dual-Beam System and Its Phase-Referencing Capability
Mareki Honma,T. Fujii,Tomoya Hirota,K. Horiai,Kenzaburo Iwadate,Takaaki Jike,Osamu Kameya,Ryuichi Kamohara,Yukitoshi Kan-ya,Noriyuki Kawaguchi,Hideyuki Kobayashi,Seisuke Kuji,Tomoharu Kurayama,Seiji Manabe,Takeshi Miyaji,Kouichirou Nakashima,Toshihiro Omodaka,Tomoaki Oyama,Satoshi Sakai,Sei-ichiro Sakakibara,Katsuhisa Sato,Tetsuo Sasao,Katsunori M. Shibata,Rie Shimizu,Hiroshi Suda,Yoshiaki Tamura,Hideki Ujihara,Akane Yoshimura +27 more
TL;DR: In this paper, the results of the first dual-beam observations with VERA (VLBI Exploration of Radio Astrometry) were presented, and the results demonstrate the high capability of phase referencing, indicating that it is a promising tool for phase-referencing VLBI astrometry at 10 µas-level accuracy.
Journal ArticleDOI
First Fringe Detection with VERA's Dual-Beam System and its Phase Referencing Capability
Mareki Honma,T. Fujii,Tomoya Hirota,K. Horiai,Kenzaburo Iwadate,Takaaki Jike,Osamu Kameya,Ryuichi Kamohara,Yukitoshi Kan-ya,K. Kawaguchi,Hideyuki Kobayashi,Seisuke Kuji,Tomoharu Kurayama,Seiji Manabe,T. Miyaji,Kouichirou Nakashima,Toshihiro Omodaka,Tomoaki Oyama,Satoshi Sakai,Sei-ichiro Sakakibara,Katsuhisa Sato,Tetsuo Sasao,Katsunori M. Shibata,R. Shimizu,Hiroshi Suda,Yoichi Tamura,Hideki Ujihara,A. Yoshimura +27 more
TL;DR: The first dual-beam observations of a pair of H2O maser sources W49N and OH43.1 have been carried out on 2002 May 29 and July 23 as discussed by the authors.
Journal ArticleDOI
Intercontinental comparison of optical atomic clocks through very long baseline interferometry
Marco Pizzocaro,Mamoru Sekido,K. Takefuji,K. Takefuji,Hideki Ujihara,H. Hachisu,Nils Nemitz,Masanori Tsutsumi,Tetsuro Kondo,Tetsuro Kondo,Eiji Kawai,Ryuichi Ichikawa,Kunitaka Namba,Yoshihiro Okamoto,Rumi Takahashi,Jun-ichi Komuro,Cecilia Clivati,Filippo Bregolin,Piero Barbieri,Alberto Mura,E. Cantoni,Giancarlo Cerretto,Filippo Levi,Giuseppe Maccaferri,Mauro Roma,Claudio Bortolotti,Monia Negusini,Roberto Ricci,Giampaolo Zacchiroli,J. Roda,Julia Leute,Julia Leute,Gérard Petit,Federico Perini,Davide Calonico,Tetsuya Ido +35 more
TL;DR: In this paper, very long baseline interferometry (VLBI) is used to compare two optical clocks located in Japan and Italy through the observation of extragalactic radio sources.
Journal ArticleDOI
Astrometry of 6.7 GHz Methanol Maser toward W 3(OH) with Japanese VLBI Network
Naoko Matsumoto,Mareki Honma,Yasuko Isono,Hideki Ujihara,Kimihiro Kimura,Kouhei Matsumoto,Satoko Sawada-Satoh,Akihiro Doi,Kenta Fujisawa,Yuji Ueno +9 more
TL;DR: In this paper, the results of multiepoch VLBI observations for a 6.7 GHz methanol maser toward the UC H II region of W 3(OH) with Japanese VLBi Network (JVN) were derived, and the trigonometric annual parallax to be 0.598 ˙ 0.067 mas.
VERA: A New VLBI Instrument Free from the Atmosphere
Hideyuki Kobayashi,Tetsuo Sasao,N. Kawaguchi,Seiji Manabe,Toshihiro Omodaka,Osamu Kameya,Katsunori M. Shibata,T. Miyaji,Mareki Honma,Yoichi Tamura,Tomoya Hirota,Seisuke Kuji,K. Horiai,S. Sakai,Katsuhisa Sato,Kenzaburo Iwadate,Yukitoshi Kan-ya,Hideki Ujihara,Takaaki Jike,T. Fujii,N. Motiduki,Tomoaki Oyama,H. Kurayama,Ryuichi Kamohara,Hiroshi Suda,T. Kasuga +25 more
TL;DR: The VERA system as mentioned in this paper is the first VLBI array to be designed to be free from the atmosphere phase fluctuations, and it has four antennas with 2,300 km maximum baseline length in Japan.