Satellite VHF transponder time synchronization

Abstract-This paper describes an experiment designed to transfer ments have been conducted [I], [2] previously using satel-accurate time between two widely separated clocks using a VHF satellite Satellite, ATS-1. The experiment used atomic oscillators to maintain ac-curate time at each station, and the synchronization was accomplished by measuring the round-trip delay times between the stations. The goal of the experiment was to evaluate a VHF system, because of the low-cost ground equipment involved, in contrast to microwave systems. The paper discusses the results and the various factors that contributed to the timing errors. lites with microwave transponders. The present experiment transP’”’der * The &elbte used was the NASA Applications T=h””l”gy was conducted with the ATS-1 VHF transponder. Although the microwave frequency region is ideal from the point of system has an advantage in that relatively simple and low-clocks was achieved to within a few microseconds. view of avoiding atmospheric signal distortion, the VHF cost ground equipment may be used. Synchronization ofth