Collaboration between DTAG, PTB and AGH Time & Frequency Dissemination SDH Bremen UTC(DTAG) Braunschweig UTC(PTB) 76,9854,2 47,89 44,3 Objectives: Enable time comparison between (German) UTC-labs using optical fiber: here: PTB-DTAG DTAG: feasibility study of installed telecom fiber for time dissemination Dissemination of „traceable“ time UTC(x) Investigating and pushing the limits of TTOF
Lopped setup – source of signals and measurements in Braunschweig 1 pps is measured with Time interval counter TIC resolution ≈10 1s 10 MHz is measured with K&K counter ( -Mode) Counter resolution <200 1s enhanced by dual mixer method Additional tapping module in Bremen allows for singal extraction Sliwczynski, L.; Krehlik, P., "Multipoint joint time and frequency dissemination in delay-stabilized fiber optic links," in Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on, vol.62, no.3, pp , March 2015 Additional tapping module in Bremen allows for singal extraction Sliwczynski, L.; Krehlik, P., "Multipoint joint time and frequency dissemination in delay-stabilized fiber optic links," in Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on, vol.62, no.3, pp , March 2015
First preliminary results
Dual-Mixer Time Difference Methode with Harmonic Tracking N LPF VCO Synthesizer Hz Time Interval TIC 4100 N LPF VCO FXE Counter Ch 1 Ch 2 Ch 3 Ch Hz 1 PPS Hz 0dB N= 128 LPF 1.9 MHz N= 128 Local site Remote site