[time-nuts] Timing Distribution in Mountainous Terrain

[Matthew Kaufman]

  On 9/9/2010 8:37 AM, Ralph Smith wrote:
> We have a requirement for approximately ten radio sites to be synchronized
> to within 30 ns of each other.
30 ns seems a little closer than most radio site applications need... 
what drives this requirement?
> Ordinarily you could throw in an
> appropriate GPSDO and be done with it. However, we also have the
> reqirement to be able to operate independent of GPS for up to six days.
Wow, ok, and what drives *that* requirement? Can you use any other 
mutually visible thing, or do we assume all satellites have vanished 
from orbit?

Matthew Kaufman