光纤双向时间传递链路校准及验证方法研究OA

Two-Way Optic-fiber Time Transfer(TWOTT)is currently one of the most accurate time transfer methods in terms of uncertainty performance,capable of achieving repeatability on the order of hundreds of picoseconds.As a critical influencing factor,link calibration directly affects the accuracy of time transfer results.To address current scarcity of research on TWOTT link calibration,the lack of standardized methods,and the difficulties in verifying calibration results,this study proposes a TWOTT link calibration method based on Common Clock Difference(CCD).First,a time transfer link composed of two TWOTT devices is established.Calibration experiments are conducted under common-clock conditions,and the CCD method is employed to obtain the link calibration results.Then,an uncertainty evaluation is performed to determine the combined standard uncertainty of the link calibration.Finally,a cross-validation method utilizing experimental results from multiple time transfer links is proposed.Under laboratory conditions,different time transfer links are used to simulta-neously compare two time scales,thereby verifying the TWOTT link calibration results.The experi-mental results demonstrate that the calibration value of the time transfer link composed of two TWOTT devices is 0.189 ns,with a combined standard uncertainty of 81 ps.When three different time transfer links are used simultaneously to compare two time scales in the laboratory,the differ-ences among the obtained clock offsets all fall within the range of comparison uncertainty.These results verify the effectiveness and accuracy of the proposed TWOTT link calibration method,providing a techni-cal reference for the calibration and verification of fiber-optic time transfer links.