If you're looking for the most accurate answer to this question, altimeter measurements is not it. Altimeters measure barometric pressure and convert it to elevation based on your last calibration point. Any changes in weather (high pressure or low pressure) throws it off considerably (up to hundreds of feet). Over the average 2-week hiking period, these errors could be quite significant. If the hiker were to calibrate the altimeter to a known topo map point regularly (several times per day), then this error can be minimized, but the calibrations tie it all back to the topo map that you wanted to avoid for some reason.longri wrote:maverick wrote: I know people who measure almost every hike with an altimeter or GPS and the JFMT has been hiked at least twenty-nine trillion times. So surely it's been done.
Topo map accuracy is not perfect either, but it doesn't drift on you. GPS uses either satelite calculations, a stored topo map value (interpolated), or an internal altimeter, depending on your model. The accuracy of GPS satelite calculations for vertical control (GPS elevation) is typically not as good as horizontal control, depending on the number of satelites available and quality of the receiver.
So in the end, I think you're best off using some form of topo map data if accuracy is your issue. What is the point of all this anyway, just curious.
