Study of an Optical Fiber Time Transmission Method with Real-Time Average Temperature Measurement of Links

The temperature of optical fiber links is an important factor affecting the accuracy of optical fiber time transmission. However, the real-time temperature measurement of optical fiber links in field networks is difficult and contains many errors. In this paper, a new method for the real-time average temperature measurement of optical fiber links is proposed. By accurately measuring the round-trip time delay of the optical fiber link and filtering out the delay jitter and system noise through the Kalman filter, the real-time average temperature of optical fiber links can be accurately calculated. The experimental results in the temperature control box show that the temperature measurement accuracy of this method is about 0.015 °C. Under the condition of a significant temperature change, the time synchronization accuracy of the round-trip system can reach the sub-nanosecond level and the time stability is less than 35 ps/s and 8 ps/104 s.