Periodic GPS Auto Correction correct altitude readings based on GPS information.
Though altitude readings are corrected automatically, GPS measurement values are used, so corrected results may not necessarily match actual altitude or elevation above sea level. The altitude readings produced by this watch are obtained by subtracting the geoidal height from the ellipsoidal height.
For more accurate altitude readings when mountain climbing or trekking, remove the check mark from the "Periodic GPS Auto Correction" option and correct altitude readings manually at frequent intervals.
Altitude correction may not be possible, or correction may not be performed for long periods if GPS reception is unstable.
