systematic position error

[jaco]

Hi

I have a systematic location error, about 30 meters to East direction

I defined a GPX route (using  OPENRUNNER web site) on PC with a IGN 25K topo as background, zoomed at maximum to point very precisely my route (in mountain region). I exported the Gpx file to my smartphone (a QUECHUA) .  When I display the route on my smartphone, it is systematically shifted to East  

. I verified the LAT, LONG values in the imported GPX file : they are exact

I use IGN 25K topo maps , imported with MOBAC

Then I made the other test :

I recorded a short trip around my place in open urban environment . I displayed my track on IGN map and OPenstreetmap (ONLINE mode) : same problem , same error value and direction.

I don't think that the problem is related to the GPS chip : it would be random

In urban area, I am totally sure that GPS reception was excellent (I checked the number of satellites)

Same problem with 2 different maps on the same region : it's not the maps.

Same problem with a GPX file and with a track recorded with  the QUECHUA GPS ..

It looks like the ORUX application was misinterprating the LAT, LONG values !!!!  LoL  

Do you have an idea



thanks for your help

[orux]

Hi

I have a systematic location error, about 30 meters to East direction

I defined a GPX route (using  OPENRUNNER web site) on PC with a IGN 25K topo as background, zoomed at maximum to point very precisely my route (in mountain region). I exported the Gpx file to my smartphone (a QUECHUA) .  When I display the route on my smartphone, it is systematically shifted to East  

. I verified the LAT, LONG values in the imported GPX file : they are exact

I use IGN 25K topo maps , imported with MOBAC

Then I made the other test :

I recorded a short trip around my place in open urban environment . I displayed my track on IGN map and OPenstreetmap (ONLINE mode) : same problem , same error value and direction.

I don't think that the problem is related to the GPS chip : it would be random

In urban area, I am totally sure that GPS reception was excellent (I checked the number of satellites)

Same problem with 2 different maps on the same region : it's not the maps.

Same problem with a GPX file and with a track recorded with  the QUECHUA GPS ..

It looks like the ORUX application was misinterprating the LAT, LONG values !!!!  LoL  

Do you have an idea



thanks for your help

Hi,



I don't think so. Sure it is a map calibration problem.



Have you tested the gpx with any other map, like any online map, or a mapsforge map?



If you want to check if your map is correct:

0.-GPS off, map centre cursor always visible (settings--user interface--cursor)

1.-open the offline map at a reference point (a peak, a roundabout, ...)

2.-without scrolling the map, open an online map, like openstreetmaps.



You should see the cursor exactly in the same point at the online map.



Or open the GPX file over an online map.



orux

[jaco]

Hi



Thanks for the help

I made the test that you recommended  and with online maps, and  the position was correct.

I reimported a piece of IGN maps , same procedure as the first time ... and now the position is correct !!

the problem is for sure related to the maps generation , but I don't understand why  (error on 2 differents types of maps IGN and OSM ),

now   it is correct ...  !!!  that's good enough !!



thanks  for your quick answer