Barometric altimeter screen on the Garmin Montana 600

For folks who hike and bike in mountainous terrain, tracking elevation gain can be as (or even more) important than trail miles. But while GPS is getting very accurate in terms of horizontal positioning, it is surprisingly weak at determining elevation. While it’s a bit of an oversimplification, let’s just say that it’s primarily due to the geometry of the satellite constellation and any GPS receiver involved. Add in mountainous terrain and the situation can get worse. read more