Evaluation of performance of GPS controlled rubidium clocks

Global Positioning System (GPS) controlled rubidium clock systems are now being used widely for many precise timing applications. They also play the role of the reference time and frequency source in many laboratories. This demands the evaluation of performance of such clocks to assess their reliability. For this purpose, a special experimental campaign has been planned. The epoch time has been found to be reliable within 60 ns and frequency offset does not exceed few parts in 10 -12 . But the receiver takes few hours to achieve initial lock. Short-term stability in locked condition has been poorer than that of the rubidium clock in free running condition.