Warner Losh wrote:
>
> What I was trying to say was that SA is caused by the satellites
> reporting times that have a small offset added to or subtracted from
> them. Knowing where you are requires that you know what time it is to
> a very precise degree. Once you know what time it is, you can know
> where you are. That's why SA injects a pseudo random noise factor
> into the timing information that the satellites report. If you have
> an atomic clock and a GPS clock, you can measure the offset between
> the two fairly easily and graph the results. That is what I mean when
> I say you can compensate for the SA if you have a good atomic clock.
This is what "Differential GPS" provides: a standard time source that
can be used to remove the SA meanderings from the GPS fix.
--
"Where am I, and what am I doing in this handbasket?"
Wes Peters Softweyr LLC
[EMAIL PROTECTED] http://softweyr.com/
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