Those of you interested in pursuing GPS for various surveying projects should
check out the maritime navigation sources, and fully understand the differential
gps issue. (The DOD has intentionally degraded the accuracy of GPS, but there is
a calibration work around.) For more than just recording where you are, I highly
recommend a unit with a full numberical keypad for entry of lat long survey
points etc. There are interfaces to marine chart software for both the Mac and
IBm available, but I suspect taht no one has yet started loading topo maps or
ordnance survey maps ( at least off the shelf).
 
Benj. A.G.Fuller
seabag enterprises
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