they give altitude, accurate to within a few feet. just set
the altimeter to read the same. then you know adjusted
pressure. considering the legal requirements, it is
perfectly adequate.

see http://mtp.jpl.nasa.gov/notes/altitude/altitude.html



"Peter Duniho" wrote in
message ...
| "Jim Macklin" wrote
in message
| ...
| GPS, even a $100 hikers model will solve the problem.
|
| No, it won't.
|
|