[ntp:questions] Using parse driver rather then nmea driver?

Hal Murray hal-usenet at ip-64-139-1-69.sjc.megapath.net
Tue Oct 21 07:11:15 UTC 2008


>I am actually using three seperate BU 303 GPS devices pointing in
>different directions.

Beware of the leap-second bug.

I don't have a BU 303, but all the other SiRF units I've tried
are off by a second for some strange pattern.
  http://www.megapathdsl.net/~hmurray/ntp/leap-gps.gif
That happens when a leap-second is pending.

>I know my position to within 10m (got from a roof reading with 9 sats
>in view) so my confidence in the readings is high.
>
>I only need accuracy to about half a second but then need that machine
>to be the stratum 1 server for the other machines in the environment.
>For reasons I won''t bore you with they can't connect to an external
>network connection so this seems the best solution?

In theory, one satellite should be good enough if you know your
location.  That only works if the software in the GPS box supports
that mode.

-- 
These are my opinions, not necessarily my employer's.  I hate spam.




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