GPS trackers and altitude

All hikes start from the iron cross of Gattigues
Any attempt to get a good fix on cumulative climbing using GPS devices (handhelds, or smartphones) is fraught with error. Anyone who has used these GPS tracking devices knows that, while longitude and latitude are quite accurate, the altitude measurements at any given point vary from accurate to completely off the mark. GPS chip quality, embedded software and various external factors affect these readings. Walking at the base of a steep limestone cliff will cut out half of the sky and half of the satellite readings. Walking through a wet forest under wet leafy trees degrades the signals too. And there might be times when military services move the geopositioned satellites to serve a military purpose thereby degrading consumer level accuracy. So in this article, I compare a couple different apps to the Garmin GPSMap 64s to see if there are any conclusions. Continue reading “GPS trackers and altitude”