Distance
The distance is the sum of the segments between consecutive points. When a file has several segments — a GPS signal lost in a tunnel, for example — the gap between them is counted too, as a straight line, so the total matches what you walked.
Climb and descent
A GPS altitude jitters by several metres from one point to the next. Added up naively, this noise turns a flat walk into hundreds of metres of climb. GPX Atlas therefore smooths the altitude and ignores changes under 3 m, which are mostly noise.
- Smoothing — off, light (the default) or strong — is set in Settings › Tracks. Stronger smoothing gives a lower, steadier climb.
- Routes drawn or planned are never smoothed: their points are far apart, and smoothing would flatten real climbs.
- While recording, the climb is read on every precise GPS fix, or on the phone's pressure sensor when barometric altitude is on, with the same threshold.
- Terrain elevation (see Routes, editing, export) replaces doubtful GPS altitudes with those of a terrain model.
That is why two apps rarely agree on the climb of the same file: each filters the noise its own way, and some replace the altitudes with a terrain model without saying so. Neither is wrong; compare like with like.
Time, speed and pace
Speed and pace use the times recorded in the file. Moving time leaves out the moments slower than 0.5 m/s (1.8 km/h), so breaks don't lower your average; the threshold can be set to 0.3, 0.5 or 1 m/s in Settings › Tracks. A track without times — a planned route, a track drawn on a website — shows distance and climb only.
On the ground, the arrival time follows your speed over the last ten minutes; before that, it estimates from the distance and the climb left.
Splits, slope and sensors
- Splits come per kilometre or per mile, with the time, the climb and the pace of each; they can also be cut every 100 m of climb, for steep outings.
- Slope is shown in percent or, if you prefer, in degrees (Settings › Units and formats).
- Heart rate, cadence, power and temperature are read from the file when it has them: averages, maximums and charts. Power also gives the normalized power, over 30-second windows.
Units
Units follow your phone's country: metric, imperial, or nautical (nautical miles and knots, altitudes in metres). In Settings › Units and formats, choose them freely, and speed, altitude and temperature separately.
