High-precision time interval measuring method and device applied to optical fiber time transfer

Abstract

The invention discloses a high-precision time interval measuring method and device applied to optical fiber time transfer. The high-precision time interval measuring method comprises the following steps: adopting a pulse filling method to complete rough measurement on measured time interval; adopting a method of performing phase discrimination through a local frequency signal and a restored carrier frequency signal to complete fine measurement on the measured time interval; and correcting system errors by combining rough measurement results and fine measurement results through an arithmetical unit to obtain precise measurement results of the time interval. The high-precision time interval measuring method is suitable for conditions that a transmitted time signal and frequency signal are homologous in the optical fiber time transfer. Time interval measuring precision can reach 3 ps. Compared with an existing time interval measuring method, the high-precision time interval measuring method has the characteristics of high measuring precision and low cost.

Description

technical field [0001] The invention belongs to the technical field of time synchronization and relates to a high-precision time interval measurement method, in particular to a high-precision time interval measurement method and device applied to optical fiber time transfer. Background technique [0002] Among many time synchronization methods, the optical fiber time transfer method can achieve higher synchronization accuracy, and the equipment price is much lower than the satellite two-way comparison method, so the optical fiber time transfer method has broad application prospects. To achieve high-precision optical fiber time transfer, it is first necessary to accurately measure the transmission delay of the time signal in the optical fiber, and then accurately control the time signal according to the measurement results, so as to achieve high-precision synchronization. An important factor that restricts the synchronization accuracy of optical fiber time transfer is the mea...

AI Technical Summary

Problems solved by technology

But these methods are somewhat deficient in fiber optic time transfer

The TDC chip method is low in cost and small in size, but its measurement range is small, ranging from hundreds of ns to several ms, which is difficult to meet long-distance use, and the measurement accuracy can only reach 22ps; the FPGA method is low in cost and small in size The measurement range is large, but the measurement accuracy is only a few hundred ps; the time interval measurement module method, such as Agilent's U1050A, although the accuracy is as high as 5ps, but the cost is too high. The general counter method, such as SR620 and Agilent 53230, its measurement accuracy It can reach 20ps, and the measurement range can also be large, but the volume is large and the cost is high, so it is not suitable for use in optical fiber time transfer equipment

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