Title :
First results of real-time time and frequency transfer using GPS code and carrier phase observations
Author :
Jarlemark, P. ; Jaldehag, K. ; Rieck, C. ; Johansson, J.
Author_Institution :
SP Swedish Nat. Testing & Res. Inst., Boras, Sweden
Abstract :
We have used code and carrier phase data from the global positioning system (GPS) satellites to estimate time differences between atomic clocks in near (<10 s) real-time. For some sites we have used data transmitted via Internet connections and TCP/IP, while for other sites data were collected in deferred time, but processed by a Kalman filter-based software as if they were available in real time. Satellite orbit and clock data of different quality have been used. The real-time estimates of time differences of the station clocks have been compared to those estimated from regular postprocessing using accurate satellite orbits and clocks from the international GPS service (IGS). First results show that the standard deviation of the differences between the real-time carrier phase-based and the postprocessing estimates of the clock time differences can be less than 100 ps for baselines of about 1000 km.
Keywords :
Kalman filters; atomic clocks; real-time systems; time measurement; time-frequency analysis; 100 ps; 1000 km; GPS; Internet connections; Kalman filter; atomic clocks; carrier phase observation; clock time difference; global positioning system; international GPS service; real-time; satellite orbit; station clocks; time-frequency transfer; Atomic clocks; Frequency; Global Positioning System; Information filtering; Internet; Kalman filters; Phase estimation; Real time systems; Satellites; TCPIP;
Conference_Titel :
Frequency Control Symposium and PDA Exhibition Jointly with the 17th European Frequency and Time Forum, 2003. Proceedings of the 2003 IEEE International
Print_ISBN :
0-7803-7688-9
DOI :
10.1109/FREQ.2003.1275111