What is this "lag" in coordinates ?

[LaurentG]

Hi all,

I just discovered incidently something that I cannot understand.... while I'm sure that a lot of experts in this forum will be able to explain me easily 

Coordinates as they are specified in a GPX (or KML) file are not the same than those that are displayed in OruxMaps.
For example, if I have in OM a trackpoint whose cordinates are 45.18400°N 5.7997°E (as displayed by OruxMaps) and then I export it in a GPX file, its coordinate in the GPX file are lat="45.1830653" lon="5.7188988"
Not so far... but clearly not the same

And If I have a look on this place in OpenStreetMap (or in GoogleMaps, or in french Geoportail) in a browser, coordinates displayed are the same than in GPX file, and not the same than those displayed in OruxMaps.

I guess it could be due to some parameter set in OruxMaps... but I reviewed all the parameters.... and didn't find anything that could explain this difference.
The only parameter that I have found and supposed to have an impact on how coordinates are displayed is Global Settings/Units/Coordinates (that is set in my case to degrees(00.0000°))

Any help is welcome !

PS : If we enter both coordinates in GoogleMaps or OpenStreetMap, we can see that both points are distant of 6.4 km

[LaurentG]

No one knows ? 

Do you have the same issue, or is it only on my copy ?
I am running OM 7.4.23

[Juanjo]

Hi,

is oruxmaps showing those 'wrong' coordinates on any map or just a particular one?

If they appear to be wrong on a particular offline map:

- did you 'recalibrate' it?
- did you change the datum?

You can check that oruxmaps is displaying the same coordinates than a browser using OpenStreetMap on both. In my case it does.

Cheers

[LaurentG]

Hi,
thanks you for answer.
I have the lag whatever the map that is displayed, offline or even online. Clearly, that doen't come from the map.

The most strange being that if I create a Waypoint, coordinates of the waypoint (displayed if I click on it) and coordinate of the map (as displayed in dashboard if I center the map on the waypoint) are the same.
But if I export the waypoint (from Manage Waypoints menu) to a GPX (or KML) file, the coordinates written in the GPX file are different.
And the coordinates as they are in the GPX file are identical to coordinates provided by OpenStreetMap, or GoogleMaps, or French Geoportail.
While coordinates displayed INSIDE OruxMaps are then different...

Actually, it's would be better than both are identical, but the most important is that those that are in the GPX file are OK : otherwise, we couldn't exchange GPX (or KML) files between OruxMaps and other tools. Hopefully, it's the case, and then, have display in OruxMaps (and ONLY display) different is not really a big issue.

But very very strange.

It's the reason why I initially imagined it was due to a parameter in OruxMaps I would have unvoluntarily modified.... but I do not have found any parameter that could explain....

You wrote that in your case, you do not have discrepancy between coordinates displayed by OruxMaps and by OpenStreetMap in a browser : Which version of OruxMaps do you run ? Is it 7.4.23 like me (the last free version on OruxMaps website), or one 8.xx "Donate" coming from GooglePlay ?

[Juanjo]

Strange indeed.
I checked with both, the free 7.4.23 and 8.1.10 GP
Can you attach a screenshot of oruxmaps showing a point on openstreetmap and a link (with a marker) to the same point in OSM main website?

Edit

I can reproduce it by changing the Datum of the map.
To fix the issue go to 'Maps - Map tweaks - Map Datum' and select WGS 1984:Global definition, the first in the list. Coordinates in GPX/KML are always in WGS1984, hence the difference.

[LaurentG]

Your remark "Did you change the datum ?" arrested me.
No, clearly, I did not do it voluntarily, but maybe involuntarily?
So I explicitly reset the datum at WGS1984 ... and since the problem has disappeared.
So that was that.

Thank you for your help !

Actually, when you change the datum, the new datum selected is not displayed nowhere by default. (You can CHOOSE to display it in the dasboard, and I think that now, I'll display it in the dasboard  ), and even if we open the menu "Map Datum", current value is not visible... So I didn't have even idea that my Datum could be another one...

[Juanjo]

Our reply crossed each other. See my edited reply 

[LaurentG]

Thank you again