Zobrazeno 1 - 10
of 23
pro vyhledávání: '"Hidekazu Hachisu"'
Autor:
Ryuichi Ichikawa, Hidekazu Hachisu, Mamoru Sekido, Tetsuya Ido, Yoshifumi Hiraoka, Eiichirou Harima, Shuntaro Fukaya, Masahiro Nakashima, Koji Matsuo, Yuichi Aoyama, Akihisa Hattori, Yoichi Fukuda
The frequency accuracy of optical atomic clocks has dramatically increased over the past 15 years, improving by more than two orders of magnitude from 16 digits of precision to 18 or even 19 digits of precision. Since around 2015 researchers from aro
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::16b5886435fef4b1a72a8535820b4ded
https://doi.org/10.5194/egusphere-egu23-2983
https://doi.org/10.5194/egusphere-egu23-2983
Autor:
Yuko Hanado, Tetsuya Ido, Fumimaru Nakagawa, Hidekazu Hachisu, Nils Nemitz, Hiroyuki Ito, Tadahiro Gotoh
Publikováno v:
Proceedings of the 52nd Annual Precise Time and Time Interval Systems and Applications Meeting.
The optical lattice clock NICT-Sr1 [1] regularly reports calibration data for the international atomic time TAI, obtained by intermittent measurements of a flywheel hydrogen maser. Continuous frequency measurements of this maser against the local UTC
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::b1951a63d452ddfeb55db5a05a9bdcbf
https://doi.org/10.33012/2021.17787
https://doi.org/10.33012/2021.17787
Autor:
Filippo Levi, J. Roda, Masanori Tsutsumi, Roberto Ricci, Kunitaka Namba, Claudio Bortolotti, Hideki Ujihara, Rumi Takahashi, Hidekazu Hachisu, Mauro Roma, Piero Barbieri, Tetsuro Kondo, Kazuhiro Takefuji, Eiji Kawai, Cecilia Clivati, Mamoru Sekido, Jun-ichi Komuro, Davide Calonico, Giuseppe Maccaferri, Filippo Bregolin, Tetsuya Ido, Alberto Mura, Marco Pizzocaro, Yoshihiro Okamoto, Monia Negusini, Giancarlo Cerretto, Gérard Petit, Nils Nemitz, Giampaolo Zacchiroli, Julia Leute, Federico Perini, Ryuichi Ichikawa, E. Cantoni
Publikováno v:
Proceedings of the 52nd Annual Precise Time and Time Interval Systems and Applications Meeting.
For the aim to enable precise frequency transfer over earth radius scale distance, NICT developed a broadband VLBI system observing 3-14 GHz radio frequency range, and that was implemented in a pair of transportable 2.4m diameter VLBI stations and Ka
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::dbd760c1f752860373bd093768f73ef6
https://doi.org/10.33012/2021.17776
https://doi.org/10.33012/2021.17776
Autor:
Nozomi, Ohtsubo, Ying, Li, Nils, Nemitz, Hidekazu, Hachisu, Kensuke, Matsubara, Tetsuya, Ido, Kazuhiro, Hayasaka
Publikováno v:
Optics letters. 45(21)
We report on the first, to the best of our knowledge, frequency ratio measurement of an
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=pmid________::5c98adb29c385d4b292021807513943d
https://pubmed.ncbi.nlm.nih.gov/33137047
https://pubmed.ncbi.nlm.nih.gov/33137047
Publikováno v:
Scientific Reports, Vol 8, Iss 1, Pp 1-12 (2018)
Scientific Reports
Scientific Reports
Time scales consistently provide precise time stamps and time intervals by combining atomic frequency standards with a reliable local oscillator. Optical frequency standards, however, have not been applied to the generation of time scales, although t
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::2c2fc0238335fdb17df8f590c43bf46e
http://link.springer.com/article/10.1038/s41598-018-22423-5
http://link.springer.com/article/10.1038/s41598-018-22423-5
Autor:
Tadahiro Gotoh, Yuko Hanado, Nils Nemitz, Fumimaru Nakagawa, Hidekazu Hachisu, Hiroyuki Ito, Tetsuya Ido
Publikováno v:
Metrologia. 58:025006
The optical lattice clock NICT-Sr1 regularly reports calibration measurements of the international timescale TAI. By comparing measurement results to the reports of eight primary frequency standards, we find the absolute frequency of the 87Sr clock t
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::f0ac3921bec83905d96763bcc64f947c
https://doi.org/10.1088/1681-7575/abc232
https://doi.org/10.1088/1681-7575/abc232
Autor:
Miho, Fujieda, Sung-Hoon, Yang, Tadahiro, Gotoh, Sang-Wook, Hwang, Hidekazu, Hachisu, Huidong, Kim, Young Kyu, Lee, Ryo, Tabuchi, Tetsuya, Ido, Won-Kyu, Lee, Myoung-Sun, Heo, Chang Yong, Park, Dai-Hyuk, Yu, Gerard, Petit
Publikováno v:
IEEE transactions on ultrasonics, ferroelectrics, and frequency control. 65(6)
Advanced satellite-based frequency transfers by two-way carrier-phase (TWCP) and integer precise point positioning have been performed between the National Institute of Information and Communications Technology and Korea Research Institute of Standar
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=pmid________::528ed16ad7abca6e7fa50b485309479b
https://pubmed.ncbi.nlm.nih.gov/29856714
https://pubmed.ncbi.nlm.nih.gov/29856714
Publikováno v:
Optics express. 25(8)
SI-traceable measurements of optical frequencies using International Atomic Time (TAI) do not require a local primary frequency reference, but suffer from an uncertainty in tracing to the SI second. For the measurement of the
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=pmid________::4b9ac5c688df3a8d284dd5c8d681bdb4
https://pubmed.ncbi.nlm.nih.gov/28437930
https://pubmed.ncbi.nlm.nih.gov/28437930
Publikováno v:
The Precise Time and Time Interval Systems and Applications Meeting.
Real signal of time scale with reference to an optical clock was continuously generated for five months. The parameter of the steering entered to a phase micro stepper was determined by the prediction of a hydrogen maser frequency, which was in accor
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::7e9360d63274b5d12b43e9bfb20a5c59
https://doi.org/10.33012/2017.15009
https://doi.org/10.33012/2017.15009
The absolute frequency of the $^{87}{\rm Sr}$ clock transition measured in 2015 was reevaluated using an improved frequency link to the SI second. The scale interval of International Atomic Time (TAI) that we used as the reference was calibrated for
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::7835e2af7a63abe316a6a818193368f7
http://arxiv.org/abs/1611.08668
http://arxiv.org/abs/1611.08668