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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