Fiber based one-way time transfer with enhanced accuracy

Ebenhag, Sven-Christian; Hedekvist, Per Olof; Johansson, Jan M.

doi:10.1109/eftf.2010.6533648

Cited by 8 publications

(3 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The first proof-of-concept was presented in 2009 [18], using modulated lasers at 1310nm and 1550nm and wavelengths at 1535 and 1553nm [19]. Those results showed the possibility to perform a oneway time and frequency transfer with two wavelengths and by evaluate these two against each other, create a correction signal for compensation for influences along the transmission path.…”

Section: Introductionmentioning

confidence: 99%

“…This has been investigated previously [16][17][18][19][20][21][22][23][24] resulting in a scale factor inversely proportional to the wavelength separation, estimated to approximately 300 when the wavelengths are 23 nm apart [16]. The wavelengths are preferably chosen in the standardized channel of wavelength division multiplexed (WDM) systems.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Real-time phase stabilization utilizing two color one-way frequency transfer

Ebenhag

Hedekvist

2012

2012 IEEE International Frequency Control Symposium Proceedings

Self Cite

View full text Add to dashboard Cite

The two color one-way frequency transfer in optical fiber is an alternative method to two-way time and frequency transfer that is useful if there are unknown asymmetries in the connection. The method is possible to use in existing infrastructure and is able to coexist with data channels for example in WDM systems, which make it possible to broadcast to multiple users and enables the user to be anonymous to the time or frequency transfer. The goal is to develop a stable oneway transfer method comparable with well-established two-way methods, with a precision and accuracy comparable to readily used satellite-based methods. The recent progress in the determination of the error sources introduced by the equipment used for phase comparisons as well as results from increasing the modulation frequency is presented. It is shown how the increase in frequency also enhances the precision, and a result from real time phase stabilization is presented. Furthermore, results from the introduction of a third wavelength are presented, with experimental data over one week periods.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Real-time phase stabilization utilizing two color one-way frequency transfer

Ebenhag

Hedekvist

2012

2012 IEEE International Frequency Control Symposium Proceedings

Self Cite

View full text Add to dashboard Cite

show abstract

“…Its precision, however, is limited by multipath effects and propagation delay fluctuations caused by the troposphere and the ionosphere [1]. Fiber-optic time transfer is extensively considered to be a promising approach to realize higher precision time transfer over long distance due to its unique advantages of high stability, broad bandwidth, low loss, and so on [2], [3]. Up to now, fiber-optic time transfer over several hundred kilometers has been demonstrated [4]- [7] with the employment of bidirectional amplification techniques in a single fiber [7]- [9], including in laboratory and in field through telecom networks.…”

Section: Introductionmentioning

confidence: 99%

High-Precision Time Transfer Over 2000-km Fiber Link

Zhang

et al. 2015

IEEE Photonics J.

View full text Add to dashboard Cite

The two-way fiber-optic time transfer based on bidirectional time-division multiplexing transmission over a single fiber with the same wavelength (BTDM-SFSW) is an effective way to eliminate the effect of Rayleigh backscattering and reach the maximum bidirectional symmetry at the same time. In this paper, a BTDM-SFSW-based time transfer testbed is built with the employment of loop configuration in the laboratory to evaluate the performance of fiber-optic time transfer over thousands of kilometers, which is confronted with worse signal-to-noise ratio (SNR), more serious fiber dispersion, and so on. The contributions of different factors, including the precision and stability of transmitted wavelengths, the power dependence of transceivers' receiving delays, Sagnac effect, etc., to the uncertainty of time transfer are investigated by theoretical analyses and experimental measurements. A full uncertainty budget for the BTDM-SFSW-based time transfer is provided. Experimental results show that the stabilities of less than 89 ps/s and 23 ps/10 5 s can be achieved for the time transfer over a 2000-km fiber link. The theoretical expanded uncertainty with the coverage factor k ¼ 2 can be less than 100 ps without the requirement of a fiber link calibration, which is validated by experimental results as well.

show abstract