uphill and downhill heights are far too high

[locusfan]

Hi

When recording tracks and showing track information, locus sums up all uphill and downhill movements and displays them as total sums. However, theese calculated heights are way too heigh compared to reality. In fact, they are displayed numbers are between double and triple as heigh as in reality.
Today I made a trip, and locus reports a total uphill and downhill height of 2260m. My barometric altimeter says 1250m, which is realistic.
I had another trip where the difference was close to factor three!

To check, what's going on, I exported the track taken today to gpx and imported it to google earth and told google earth to correct the heights to ground. Google reports a to total uphill height of 1221m - which is close to the barometric measurement. The displayed height profile is more or less smooth.

Then I imported the track to google earth without correcting heights. Now I see a wild up and down in the height profile. This explains the enormous deviation. Obviously the heights of the GPS device are not very precise.

So I suggest to implement in Locus some kind of smoothing or averaging. Without smoothing the measured heights are not usable at all.

Thanks Locusfan

[Khaytsus]

I'll be watching this to see what Menion says..  I was thinking a ride I did a while back didn't have quite as much climbing as Locus said it did.  There's always room for bugs (sorry Menion ) but I'd say his algo is fairly simple; every foot you climb it increments the total climb.  Even if you're rolling up and down 1 foot 100 times, assuming it's recording all of that data, that's 100 feet of climbing.  I certainly could be wrong though.

[Menion]

hi guys,
  this is little bit funny because this was discussed here viewtopic.php?f=10&t=728

  In locus is already small filter that do some computation on altitude before save. Just a little to remove really huge nonsense. Problem with altitude in phones is that accuracy in vertical plane is much worst then in horizontal. So even when you ride on flat, altitude will probably change a little (maybe meter on 10 meters) so it all count in altitude summary in Locus. In mentioned topic, I talked about possibility to set filter strength also on altitude (it's already working on orientation) but this was never realized. Maybe this should help, so If you'll expect not so hilly terrain and also don't care about exact altitude values, then some stronger filter should come handy. And opposite ... what you think?

[Khaytsus]

hi guys,
  this is little bit funny because this was discussed here viewtopic.php?f=10&t=728

  In locus is already small filter that do some computation on altitude before save. Just a little to remove really huge nonsense. Problem with altitude in phones is that accuracy in vertical plane is much worst then in horizontal. So even when you ride on flat, altitude will probably change a little (maybe meter on 10 meters) so it all count in altitude summary in Locus. In mentioned topic, I talked about possibility to set filter strength also on altitude (it's already working on orientation) but this was never realized. Maybe this should help, so If you'll expect not so hilly terrain and also don't care about exact altitude values, then some stronger filter should come handy. And opposite ... what you think?

Yeah, cellphones barely get the horizontal position close in good conditions (and pretty bad when moving or with any obstructions), but as you say, vertical position on phones is usually pretty terrible.  I doubt it's even consistently bad..  My phone I've seen it say I'm between 600 and 1200 feet at the house, when it's 984.

As you say, filtering is pretty scenario-specific..  Maybe on the Info page the filter could be changed if anywhere, so you could see the difference in one place?  Dunno.