How the Moon Impacts Subsea Communication Cables: Conclusions, Acknowledgments, and References

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21 Aug 2024

Author:

(1) Lothar Moeller, SubCom, Eatontown, NJ 07724, USA, lmoeller@subcom.com.

Abstract and Introduction

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.

7. REFERENCES

[1] G. Marra, C. Clivati, R. Luckett, A. Tampellini, J. Kronjäger, L. Wright, A. Mura, F. Levi, S. Robinson, A. Xuereb, B. Baptie, D. Calonico, “Ultrastable laser interferometry for earthquake detection with terrestrial and submarine cables.” Science, eaat4458, (2018).

[2] M. Newland, M. Cantono, M. Salsi, V. Kamalov, V. Vusirikala, Z. Zhan, “SubHertz Spectral Analysis of Polarization of Light in a Transcontinental Submarine Cable,” ECOC 2020, Brussels, (2020).

[3] Li Wang, Y. Wang, J. Wang , F. LI, “A High Spatial Resolution FBG Sensor Array for Measuring Ocean Temperature and Depth,” Photonic Sensors, (2018).

[4] B. Howe, B. Arbic, J. Aucan, C. Barnes et al. “SMART Cables for Observing the Global Ocean: Science and Implementation,” Front. Mar. Sci. 6, 424 (2019). https://www.osti.gov/pages/servlets/purl/15 58213

[5] Z. Zhan, “Distributed Acoustic Sensing Turns Fiber‐Optic Cables into Sensitive Seismic Antennas,” Seismological Research Letters. 91, pp.1–15, (2020).

[6] R.D. Ray, (2013), “Precise comparisons of bottom-pressure and altimetric ocean tides,” J. Geophys. Res. Oceans, 118, pp. 4570– 4584, (2013) doi:10.1002/jgrc.20336. https://agupubs.onlinelibrary.wiley.com/doi/ epdf/10.1002/jgrc.20336

[7] R.D. Ray, “A Global Ocean Tide Model From TOPEX/POSEIDON Altimetry: GOT99.2,” NASA/TM-1999-209478, (1999) https://ntrs.nasa.gov/citations/19990089548.

[8] A. Bertholds, R. Dandliker, “Deformation of Single-Mode Optical Fibers UnderStatic Longitudinal Stress,” JLT, vol. LT-5, No. 7, pp. 895-900, (1987).

[9] Richard G. Budynas and Ali M. Sadegh, “Roark's Formulas for Stress and Strain,” McGraw-Hill Companies, ISBN 9781260453751.

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