Weird navigation after curves

Since some time I’m using kurviger pro and after trying several other apps and planning combinations and I do like it very much.
Unfortunately I have a navigation problem which tracks me and my bike offroute, mainly after curves, crossings or stops (without stopping the app).
As you can see on the screenshot and a visualization of the track my phone (or the app) looses the real position and tracks me in a straight direction away from my last position. After some time the position is found again and I’m back on track.

If I understand functionality of the gpx track right, the app gets a gps position which slowly moves through the neighborhood of the last known position.
Is this because my GPS signal is bad? Is the a kind of heuristic if the signal is lost? But the app looks like the signal is good. Also a GPS test app I tried seemed to be satisfied with the signal.
Sometimes I had the feeling there might be an issue with the compass, because the arrow is positioned crosswise to the direction of the street, but the compass of the device is calibrated.
Device: Samsung Galaxy S5mini in offline mode
Many thanks in advance for any help.

Navigation works with GPS, so everything depends on device’s GPS quality.

Is it navigation with the screen on or off?

You can try some options to see if it improves on your device:

  • Change location provider in “Settings | Location | Location service”
  • Reduce GPS errors with “Settings | Location | Kalman filter”


  • the phone is mounted on the handlebar, so normaly there should not be a problem with the the GPS quality. But without knowing much about gpx tracks and the GPS accuracy I recognized, that hdop in the file mostly is 48 if I’m offroute and 24 or 32 if I’m onroute.
  • The phone is always on if I’m using kurviger.
  • currently the location service is android
  • the kalman filter is already in use.

On my next tour I’m

  • going to check the google location service
  • try another phone
  • track via OSMant and see if there is the same behaviour.
    Any other option I may try? What about “Geglättete Bewegung” (smoothed movement?)

What normally happens if the GPS signal is lost / is bad? Is the described behaviour the behaviour I have to expect?
I have checked the “Standortgenauigkeit” (position accuracy?). But I did not recognize a difference if I’m offroute. How a bad GPS signal would be displayed?
Do you have any idea why the route normally ist lost after curves?
Sorry for asking “holes in the stomach”.

You can try different options, like another location service and/or disable Kalman filter.
(smooth movement is for display purposes, it does not affect GPS quality)

Location accuracy circle is visible when is big and map is in large zoom to show it.

When GPS is lost there is no GPS location data for apps to process,
so jumps and straight lines appear in track recording and navigation.

today I tried a route with different parameter settings and logged the GPS data with the app.
Do not really know if it may help somebody, but here are the tracks:
Used device: Samsung Galaxy S5mini. Internet by bluetooth tethering.
The phone is loaded via USB. Mounted on handlebar and display is on.
All tracks were recorded sequentially. I tried to ride all tracks in the same manner, but I was not the only one on the road.

1st track: location service: android, kalman filter checked

2nd track: location service: google, kalman filter checked

3rd track: location service: google, kalman filter unchecked

In addition I checked two additional setups:
4th track: location service: google, kalman filter checked, no route, display off

and with another phone (Samsung Galaxy A3 (2017):

So by unchecking Kalman filter I get better routing results. Using different location services are more or less irrelevant. For me it sounds interesting, that I get better results when I do no routing and switch off the display, even if the kalman filter is checked. The A3 phone is newer and has a better performance.
May the problems founded on performance issues?


Thanks for the detailed report.

Each device has a different GPS sensor with different sensitivity and quality.
(and different Android)

Kalman filter may work better (or not) on each device, that’s why it’s optional.
(its predictions may add inertia)

That is because Kalman filter (if it’s checked) is activated automatically only in navigation.

Have you tried, to switch the phone off?
Don’t just restart, but switch off S5 mini, then start it up again!
Have you checked that the cover for the smartphone, or the mounting kit does not disturb the GPS signal?

First let me say your support is awesome. I never thought to get so many tips in so short time. Thanks.
Also thanks to devemux86 for trusting I may understand the description of the kalman filter :wink:

Yes the phone was restarted several times. I do have the behaviour since longer times.
Also it should be not because of disturbance because there is no cover, and the display is at fresh air, the mount is of pure plastic and the Galaxy A3 works.
Is there any possibility to save performance? I still have the feeling, that the behaviour is the result of an performance issue.

Could be, since “Kalman filter” (like “Smooth movement”) adds much more workload on CPU.

Also Kalman filter is known to add inertia, so if your device works better without it, it is ok to disable it.

Similarly you can select the location service (Android or Google) that works better with your device. :slightly_smiling_face:

Hallo zusammen,

ich lese immer etwas von Kalman Filter die ich in Apps aktivieren kann. Leider werde ich aus den Englischen Beiträgen und Erklärungen im Netz nicht schlau. Kann mir jemand in einfachen Worten erklären was der Kalman Filter macht und ob es sinnvoll ist diese Funktion zu aktivieren.

MATLAB has an interesting video explaining the Kalman Filter.
(the 2nd example is about navigation)

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Es gibt auch einige Youtube Videos in Deutsch :slight_smile: