I'm opening discussion on topic - altitude in Locus
I'll ... from conversation that I had with Christian over email (and also with other people here on forum)
"I noticed that the alitude difference of gpx tracks i downloaded (and checked) miscalculated in Locus (track details and diagram also). As attachement a track i want to use it for the alp cross. It has 76,38km and 802m ascendency shown in different software programs (approximately). Locus shows 387m ascendency :-( "
Altitude from GPS is generally a problem, there's no doubt about it. Question is, what's the best way, how to handle it
current solution
Current solution is quite simple, it's based only on a small small filter (set in settings), that optimize altitude a little bit before storing to database!
Altitude results (uphill, downhill, ...) are computed as a sum of altitude change on distance. So change from -2% to +2% are considered as a "flat", others are uphill, downhill
place for improvements
no filter may help to get better values to altitude. It may reduce some huge noises, but ... so question is what we should do with this, to get as good as possible results.
- possibility is to keep current system, but create better filtering method. Some more logical system, that will filter and compute better values
- locus fully support SRTM files, so it's quite easy to compute altitude values during a track record and substitude GPS altitude values, by this computed. Here is question - precision of this method. I did not test it ...
- other possibility or combination?
- you may be also fully satisfied with current system. This is also option
I'll ... from conversation that I had with Christian over email (and also with other people here on forum)
"I noticed that the alitude difference of gpx tracks i downloaded (and checked) miscalculated in Locus (track details and diagram also). As attachement a track i want to use it for the alp cross. It has 76,38km and 802m ascendency shown in different software programs (approximately). Locus shows 387m ascendency :-( "
Altitude from GPS is generally a problem, there's no doubt about it. Question is, what's the best way, how to handle it
current solution
Current solution is quite simple, it's based only on a small small filter (set in settings), that optimize altitude a little bit before storing to database!
Altitude results (uphill, downhill, ...) are computed as a sum of altitude change on distance. So change from -2% to +2% are considered as a "flat", others are uphill, downhill
place for improvements
no filter may help to get better values to altitude. It may reduce some huge noises, but ... so question is what we should do with this, to get as good as possible results.
- possibility is to keep current system, but create better filtering method. Some more logical system, that will filter and compute better values
- locus fully support SRTM files, so it's quite easy to compute altitude values during a track record and substitude GPS altitude values, by this computed. Here is question - precision of this method. I did not test it ...
- other possibility or combination?
- you may be also fully satisfied with current system. This is also option