[ntp:questions] SNTP server + ntpd 4.2.4 client
Richard B. Gilbert
rgilbert88 at comcast.net
Wed Mar 19 14:45:59 UTC 2008
Steve Kostecke wrote:
> On 2008-03-19, Noob <root at localhost> wrote:
>>Does the GPS18LVC provide an oscillator to serve time even when there
>>are not enough satellites in sight?
> No. You'll have to pay (much) more than $70-$80 if you want a good
> hold-over oscillator.
With something like 27 NAVSTAR (GPS) satellites aloft, there should
almost always be seven or eight above the horizon. Satellites more than
ten degrees above the horizon are preferred!
I've never used the GPS18LVC (I have a Motorola M12+T) but if you know
your exact location you only need one satellite to get the time. There
are four equations in four unknowns (lattitude, longitude, elevation,
and time). Not knowing any of these variables, you need four
satellites. Once you know your location a single satellite is
sufficient to solve for time.
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