Once the altitude of starting point of activity record have error value, the cloud tour.xplova.com will remind the difference value.

If the user is willing to replace the system recommends starting point altitude, select the icon "Altitude Calibration”.

 
1) Altitude Calibration:  The numbers under the icon "Altitude Calibration" indicate the starting point altitude should increase or decrease

2) If you use the recommended starting point altitude, and select the "Altitude Calibration" function

the starting point of altitude chart will moved to correct altitude, as shown