GPS Time and Frequency Dissemination
GPS is the predominant means of disseminating precise time and frequency today. In its simplest and most common form, it's somewhat more precise for frequency measurements than LORAN-C, and has the advantage of universal availability (though LORAN has a few advantages of its own). For time dissemination, GPS can't be beat, since LORAN lacks a time code.
Although I've been playing with GPS timing for a long time, I'm just now getting around to putting anything useful on this page.
My main GPS devices are a TAPR Totally Accurate Clock which uses a Motorola Oncore GPS receiver to provide a highly accurate 1 pulse per second signal, and a couple of HP Z3801A GPS-disciplined oscillators which use the same Oncore GPS to steer a 10MHz oscillator, keeping in on frequency within as few as a few parts in 1012.
I've done some work characterizing the performance of the Z3801A, and have put my Z3801A information here.
And, are some plots showing the raw stability of the 1pps signal from a Motorola M12+ Timing receiver.