I am working with GPS tracks of outdoor activities, think cycling, running, hiking. These activities often have "rest periods" where people take a break, wait at traffic lights, or just stopped their GPS for whatever reason. I end up with the raw GPS track and I am wondering how to best calculate "moving time". All gis.stackexchange.com I have looked at are very vague, and I am wondering if there is literature/methods for doing this.
I can of course go the easy route and simply look at all trackpoints and subtract all those time periods where the speed between to trackpoints is under some threshold. I would need to tweak this threshold for the activity type (I am assuming), but this seems not very elegant. I have various other ideas, but it seems to me that this problem must be common, and maybe there's a well-known solution?
Also, if anybody has any info how services such as Strava are doing it (as simple as I described above, or something more sophisticated?), it would be great to get some info about that as well.