AIM 1-1-19a(8) tells you to not to rely upon GPS altitude. Until the AIM is
changed, I'm not concerned with the details.

Bob Gardner

"Chris W" wrote in message
news:q2x0g.917$9c6.179@dukeread11...
It is my understanding that even if a GPS is reading perfectly and your
standard altimeter is reading perfectly even on a standard day that the 2
values will not be the same. Does anyone know about how far off they are
and if there is a way to calculate what the difference should be? My
guess is that at different points around the earth, the correction will be
significantly different, making a generic formula difficult if not
impossible to write.

--
Chris W
KE5GIX

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