[time-nuts] ANN: UK MSF 60 kHz interruption, 2012 June 14

Tom Van Baak tvb at LeapSecond.com
Mon Jun 4 03:55:12 UTC 2012


LF diurnal variations are considerable, in the many microseconds
range. Thus any claim of parts in 10^13 or 10^14 or 10^15 accuracy
is misleading.

Even one microsecond of atmospheric phase change over an hour
is equivalent to a 2.7e-10 apparent frequency offset. Cal labs that
still use LF signals average over an integral number of days to try
to reduce this effect. Or they upgrade to GPS where diurnal variations
are a hundred to a thousand times less.

/tvb






More information about the Time-nuts_lists.febo.com mailing list