height meter calculation?

On a longer bike tour in the north of Spain
I had always a higher height meter reading at
the end of the tour then my friends with their
Garmin device (e.g. 700 to 1000)
Transfering the gps-data to gpsies.com then the result
was the similar to Garmin.
How does Oruxmaps calculate the height meters?
Uli

Uli wrote:On a longer bike tour in the north of Spain
I had always a higher height meter reading at
the end of the tour then my friends with their
Garmin device (e.g. 700 to 1000)
Transfering the gps-data to gpsies.com then the result
was the similar to Garmin.
How does Oruxmaps calculate the height meters?
Uli

Hi, Uli;

OruxMaps uses the altitude from the gps, corrected with geoid altitude, if android provides this info.

It is strange, because altitude error (after some minutes) should be 10-20 mts.

orux

What I was talking about are the heights collected over a tour up and down.
The altitude reading is ok on Oruxmaps.
There are certainly different ways to add this heights.
E.g. a track yesterday: on oruxmaps statistic up 442m and down -528m
on gpsies.com up 316 down -326
with the same gps-data.
What could be the reason?
Uli