Remote atomic clock synchronization via satellites and optical fibers
In the global network of institutions engaged with the realization of International Atomic Time (TAI), atomic clocks and time scales are compared by means of the Global Positioning System (GPS) and by employing telecommunication satellites for two-way satellite time and frequency transfer (TWSTFT)....
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | deu |
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Copernicus Publications
2011-07-01
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| Series: | Advances in Radio Science |
| Online Access: | http://www.adv-radio-sci.net/9/1/2011/ars-9-1-2011.pdf |
| _version_ | 1818918581548613632 |
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| author | D. Piester M. Rost M. Fujieda T. Feldmann A. Bauch |
| author_facet | D. Piester M. Rost M. Fujieda T. Feldmann A. Bauch |
| author_sort | D. Piester |
| collection | DOAJ |
| description | In the global network of institutions engaged with the realization of
International Atomic Time (TAI), atomic clocks and time scales are compared
by means of the Global Positioning System (GPS) and by employing
telecommunication satellites for two-way satellite time and frequency
transfer (TWSTFT). The frequencies of the state-of-the-art primary caesium
fountain clocks can be compared at the level of 10<sup>−15</sup> (relative, 1 day
averaging) and time scales can be synchronized with an uncertainty of one
nanosecond. Future improvements of worldwide clock comparisons will require
also an improvement of the local signal distribution systems. For example,
the future ACES (atomic clock ensemble in space) mission shall demonstrate
remote time scale comparisons at the uncertainty level of 100 ps.
<br><br>
To ensure that the ACES ground instrument will be synchronized to the local
time scale at the Physikalisch-Technische Bundesanstalt (PTB) without a
significant uncertainty contribution, we have developed a means for
calibrated clock comparisons through optical fibers. An uncertainty below
40 ps over a distance of 2 km has been demonstrated on the campus of PTB. This
technology is thus in general a promising candidate for synchronization of
enhanced time transfer equipment with the local realizations of Coordinated Universal Time UTC.
<br><br>
Based on these experiments we estimate the uncertainty level for calibrated
time transfer through optical fibers over longer distances. These findings
are compared with the current status and developments of satellite based
time transfer systems, with a focus on the calibration techniques for
operational systems. |
| first_indexed | 2024-12-20T00:52:14Z |
| format | Article |
| id | doaj.art-0bb85f7d192546a6bec5ef952c32b94d |
| institution | Directory Open Access Journal |
| issn | 1684-9965 1684-9973 |
| language | deu |
| last_indexed | 2024-12-20T00:52:14Z |
| publishDate | 2011-07-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Advances in Radio Science |
| spelling | doaj.art-0bb85f7d192546a6bec5ef952c32b94d2022-12-21T19:59:12ZdeuCopernicus PublicationsAdvances in Radio Science1684-99651684-99732011-07-0191710.5194/ars-9-1-2011Remote atomic clock synchronization via satellites and optical fibersD. Piester0M. Rost1M. Fujieda2T. Feldmann3A. Bauch4Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig, GermanyPhysikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig, GermanyNational Institute of Information and Communications Technology (NICT), Tokyo, JapanPhysikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig, GermanyPhysikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig, GermanyIn the global network of institutions engaged with the realization of International Atomic Time (TAI), atomic clocks and time scales are compared by means of the Global Positioning System (GPS) and by employing telecommunication satellites for two-way satellite time and frequency transfer (TWSTFT). The frequencies of the state-of-the-art primary caesium fountain clocks can be compared at the level of 10<sup>−15</sup> (relative, 1 day averaging) and time scales can be synchronized with an uncertainty of one nanosecond. Future improvements of worldwide clock comparisons will require also an improvement of the local signal distribution systems. For example, the future ACES (atomic clock ensemble in space) mission shall demonstrate remote time scale comparisons at the uncertainty level of 100 ps. <br><br> To ensure that the ACES ground instrument will be synchronized to the local time scale at the Physikalisch-Technische Bundesanstalt (PTB) without a significant uncertainty contribution, we have developed a means for calibrated clock comparisons through optical fibers. An uncertainty below 40 ps over a distance of 2 km has been demonstrated on the campus of PTB. This technology is thus in general a promising candidate for synchronization of enhanced time transfer equipment with the local realizations of Coordinated Universal Time UTC. <br><br> Based on these experiments we estimate the uncertainty level for calibrated time transfer through optical fibers over longer distances. These findings are compared with the current status and developments of satellite based time transfer systems, with a focus on the calibration techniques for operational systems.http://www.adv-radio-sci.net/9/1/2011/ars-9-1-2011.pdf |
| spellingShingle | D. Piester M. Rost M. Fujieda T. Feldmann A. Bauch Remote atomic clock synchronization via satellites and optical fibers Advances in Radio Science |
| title | Remote atomic clock synchronization via satellites and optical fibers |
| title_full | Remote atomic clock synchronization via satellites and optical fibers |
| title_fullStr | Remote atomic clock synchronization via satellites and optical fibers |
| title_full_unstemmed | Remote atomic clock synchronization via satellites and optical fibers |
| title_short | Remote atomic clock synchronization via satellites and optical fibers |
| title_sort | remote atomic clock synchronization via satellites and optical fibers |
| url | http://www.adv-radio-sci.net/9/1/2011/ars-9-1-2011.pdf |
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