[time-nuts] Timing Distribution in Mountainous Terrain

k6rtm at comcast.net k6rtm at comcast.net
Thu Sep 9 17:49:25 UTC 2010


As far as getting a signal through mountainous terrain, look at NVIS antennas for HF -- we use them for Field Day for just that kind of communications, 200 - 300 miles in mountainous terrain. Figuring out propagation delays is going to be interesting with NVIS though. 

73 de Bob K6RTM 

Message: 3 
Date: Thu, 9 Sep 2010 11:37:46 -0400 
From: "Ralph Smith" <ralph at ralphsmith.org> 
Subject: [time-nuts] Timing Distribution in Mountainous Terrain 
To: time-nuts at febo.com 
Message-ID: <a3fa9eac817be681f75c1df76ba2adf5.squirrel at ralphsmith.org> 
Content-Type: text/plain;charset=iso-8859-1 

We have a requirement for approximately ten radio sites to be synchronized 
to within 30 ns of each other. 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. If 
we were able to have each site within line of sight of another, and could 
form a network including all sites, we could do differential time 
measurement between the mutually visible sites and correct in that way. 
Unfortunately, that is not the case. Absolute time accuracy is not 
critical, but relative time accuracy is. Does anyone out there have any 


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