Author Topic: Wierd Anomaly  (Read 2086 times)

Wierd Anomaly
« on: October 28, 2008, 10:10:01 pm »
I have a problem either with my GPS or SportTracks.... I suspect the latter

On Sunday I took a friend out to show them a possible route for a family trip, and downloaded the trip.....On to Garmin Training Centre and it shows the correct details, here it is on Bikely, a similar result appears if I download from

Yet when I download the same rout into Sport Tracks it is now nearly 600 miles and looks like this:



Has anyone else come across similar?




Craig

Re: Wierd Anomaly
« Reply #1 on: October 28, 2008, 10:27:28 pm »
There's a bug in SportTracks where if you import a track longer than about 18 hours (or 65535 seconds) you get strange results like that (so annoying for long audaxes...).
I noticed that and reported it on the SportTracks forum, and it should be fixed in a new release soon: SportTracks : Discussion Board

Though I doubt your trip is 18 hours long?
Or unless the GPX file contains a number of activities, that add up to more than 18 hours in total?

andygates

  • Peroxide Viking
Re: Wierd Anomaly
« Reply #2 on: October 29, 2008, 09:00:28 am »
Stuff the GPX into Google Earth and you'll be able to verify that it's good.
It takes blood and guts to be this cool but I'm still just a cliché.
OpenStreetMap UK & IRL Streetmap & Topo: ravenfamily.org/andyg/maps updates weekly.

Re: Wierd Anomaly
« Reply #3 on: October 29, 2008, 09:57:48 am »
Stuff the GPX into Google Earth and you'll be able to verify that it's good.

If it appears as expected in Garmin Training Centre and Bikely why do you need to try Google Earth to prove that it's correct?

No idea about this one, however I've seen some oddness when uploading GPX tracklogs to some sites (can't remember which now) where the trackpoints contained within were not in time order and the website used them in the order within the file rather than sorting by date first.

Still, that wouldn't cause it to suddenly jump over to the other side of Portsmouth Harbour like the SportTracks one has.

You could try exporting the GPX file from bikely and importing that file into SportTracks, remember that bikely exports will have time/date data stripped out.
"Yes please" said Squirrel "biscuits are our favourite things."

frankly frankie

  • I kid you not
    • Fuchsiaphile
Re: Wierd Anomaly
« Reply #4 on: October 29, 2008, 10:00:28 am »
If you switch the GPS off (or it switches itself off!) and then move, and then switch it on again -
some software interprets this as a break in the track, other software interprets it as a single track segment connected between the rest. 
That would account for the straight line across the harbour, but probably not for the rest of it.
It's not dark yet but it's getting there.

Re: Wierd Anomaly
« Reply #5 on: October 29, 2008, 10:04:35 am »
Ah yes, good point.

When uploading a multi-segment tracklog to some sites (such as Bikely) it will only display the first track segment whereas others (as FF says) will connect them all together with straight lines.

Does the GPX file contain multiple segments?
"Yes please" said Squirrel "biscuits are our favourite things."

frankly frankie

  • I kid you not
    • Fuchsiaphile
Re: Wierd Anomaly
« Reply #6 on: October 29, 2008, 06:45:34 pm »
No idea about this one, however I've seen some oddness when uploading GPX tracklogs to some sites (can't remember which now) where the trackpoints contained within were not in time order and the website used them in the order within the file rather than sorting by date first.

Hmm.  Isn't the gpx standard, to always take track points in the order they are listed (within a segment)?
So if they're timestamped and these are at odds for some reason - that could explain it.

If the timestamps are at odds, that suggests a GPS still 'warming up' or unable to see a good set of sats (in a pocket?).
It's not dark yet but it's getting there.

Re: Wierd Anomaly
« Reply #7 on: October 29, 2008, 10:01:13 pm »
Thanks folks,

The "estimated link" is something that has happened before.

Looking back - it may be the  "18 hour" glitch as I had not downloaded for several days so it is possible. Gamin do have a problem in that it fails to considers days adding "Laps" to the original day

I think I will download daily and see what happens