Strange velocity peaks in exported GPX file

[idk]

Hello, another question. I recorded some experimental tracks with Locus Pro while driving around in the car. When I look at the track statistics in Locus after i finished the record, the data is correct. For example at my yesterdays track it said maximum speed 171km/h.

But when I look at the exported gpx file in Google Earth my max speed is somehow 207 km/h and there are other very short high speed peaks that are not correct. I did three experimental tracks while driving in the car so far, and this always happens. Any idea what could be the explanation of this? Or is just Google Earth messing something up  

[Menion]

hmm quite interesting. Locus says correctly that max value is 171 and in google earth you see 207? May you share one "wrong" file?

[idk]

Haha  

No way I can really do more than 200 in my car except if I were dropped from a plane or on a trailer pulled by a Porsche Cayenne or so  :lol:

So it is not a mixup of different files.

I just took a look at further files. Also a bike trip where speed also doesn't fit. Well I guess it must be a problem of Google Earth because the Data in Locus is correct. Or could that come from the export of Data?

As I said, Locus is always correct. The data in Locus matches the data my GPS Navigation inside the car gave me and the bike data in Locus matches exactly my bike speedometer.

Some proof:

Bike: 46km/h (Locus) vs. 57 km/h (GEarth)





Car 1: 171km/h vs. 204 km/h





Car 2: 152km/h vs. 189km/h

[Menion]

quite a complex report nice ...

may you please anyway upload one recorded track here? I just want to check if this is really problem with google earth and mainly why this happen ..

[idk]

Can I sent that to you privately please cause I don't want anybody to see my exact track  

[Menion]

sure, it's not a problem, locus(@)asamm.cz

[Menion]

thanks for email ...
  interesting. In GPX file are no information about speed. It's computed from distance and time between points. Did you tried to upload your track to any site like GPSies? There you can also see some stats so if some other site will show same nonsence values like google earth.

[idk]

No I didn't try that. But I will. Does Locus use the "differential" method to compute the time? Or "should" a speed parameter be exported? Your post sounds to me like you're surprised.

[Menion]

nono, i'm not. Speed is not in GPX file. As I wrote before, it's computed from differences ...

let me know if you discover something. This is really interesting ...

[idk]

I tried to do some further investigations but I still do not get it (the cause).

I measured the distance between two waypoints in Google Earth and divided it by the time between the two points. Well... the result is the same as Google Earth says: 37.07m/2s = 44km/h

But that is not true. I did not drive 44km/h on my bike at this position. The next weird thing is... in the track overview in Google Earth it says max. Speed is 39,5km/h while one waypoint has 44. Can't be....



When I have a look at the waypoint in question in Locus it looks like this:



And this is correct!!!

So something in Google Earth is totally fucked up. Maybe the distance is calculated falsely. I don't know. Locus rules, GE sucks!!!

[Menion]

heh, this is very interesting. May you please also try upload and check your track to some more special web site like GPSies or Breadcrumbs? There you should see also some values, and I think most precise (because these sites are specialized on such tasks)

[idk]

I already tried GPSies when you first suggested it. But imo the structure of that site is a mess, had to find stuff. Anyway, I uploaded the track but it just showed distance and the track. No speed data were shown.