How the Moon Impacts Subsea Communication Cables: Conclusions, Acknowledgments, and References by@seismology
How the Moon Impacts Subsea Communication Cables: Conclusions, Acknowledgments, and References
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The study experimentally measured phase variations of an RF signal transmitted through a subsea cable between Japan and the US, revealing that tidal water pressure variations stretch the cable. This contradicts the loose tube model, showing that even minimal friction between the fiber and tube affects cable length. The results demonstrate a strong correlation between tide levels and cable length changes over daily and weeklong periods.
Author:
(1) Lothar Moeller, SubCom, Eatontown, NJ 07724, USA, [email protected].
Table of Links
GPS Long-Term Stabilized RF Phase Meter
Simple and Accurate models for tides
Latency Variations on Transpacific Cable
Poisson effect on pressurized cables
Conclusions, Acknowledgments, and References
6. CONCLUSIONS
For the first time we experimentally studied arrival phase variations of an RF signal on an optically looped-back carrier between Japan and the US. Our measurement suggests that cable length variations induced by water pressure, which depends on the tides across the pacific, stretch the fiber. This contradicts a ‘loose tube model’ for cables. The inherent coupling between the fibers and the loose tube, though this friction is very small, allows for transmittal of tension and tinily stretches them by a few ppb. We found a strong correlation between averaged tide levels and the arrival phase over daily periods. Larger offsets appear during weeklong recordings. It is surprising how long-term stable cables are but, then again, it’s remarkable how much tides cycle their length on a daily basis.
Acknowledgements
The author would like to thank R. Ray, W. Patterson, S. Bernstein, S. Abbott, B. Bakhshi, and S. Hunziker for supporting this work.
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This paper is available on arxiv under CC BY 4.0 DEED license.
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