Fig. 1. Principle of time-delay measurement

Fig. 2. Scheme of time-delay measurement

Fig. 3. Waveforms of combined signal. (a) Original combined signal of 1PPS and 100 MHz; (b) combined signal in PIN detection

Fig. 4. Waveforms of time-frequency signal. (a) Waveform comparison of 1PPS signal; (b) waveform comparison of 100 MHz source signal

Fig. 5. Time delay of system background. (a) Coarse results; (b) fine results

Fig. 6. Time delay of system background of 25 km fiber link. (a) Coarse results; (b) fine results

Fig. 7. Coarse and fine results of 25 km fiber link when temperature rises. (a) Coarse results; (b) fine results

Fig. 8. Time delay of 25 km fiber link when temperature rises

Fig. 9. Allen variance