Device Distance Recording Accuracy
May 2020 After a hike there is always some discussion about why there are so many variations in the distance recorded by phones and devices. I will try to explain the main reason why this occurs as simply as possible. I have included some screenshots of the track recorded by my Garmin on a recent hike which clearly show why the device continues to add distance even whilst stationary. GPS devices (which include phones) gather data from a group of 27 satellites that orbit Earth twice a day, following exact trajectories such that, at any given time at any given location on earth, at least four are visible. Those satellites send out radio wave signals picked up by your device. Based on the time difference between when the wave was sent and received, a GPS unit figures out how far away each satellite is and uses that info to pinpoint your location—a process known as trilateration. With the US Global Positioning System (GPS) there is a margin of error. Depending on many factors th