Laurence -
Try the following for saving a shape layer as a valid GPX file (tested
on QGIS 1.7.4/Windows 7-64 bit):
* In the dialog "Layers" right click the name of the shape layer you
want the save as a gpx file.
* Then left click on item "Save as...". This action will show a new
dialog: "Save vector layer as..."
* Under "Format" : Choose "GPS eXchange format [GPX]"
* Under "Save as": Write or browse the name for the new GPX file
* Leave "Encoding" as "System"
* Under CRS (upper dropdown): Choose "Selected CRS"
* Under CRS (lower textbox): Browse the CRS to: "WGS 84" (It's
*important* you choose "WGS 84"; the GPX format support*only* this
CRS, but QGIS will happily write your data in any CRS)
* If you have any unconventional GPX attributes in you data: Add
"GPX_USE_EXTENSIONS=yes" in the "Data source" textbox.
* Click on OK.
Regards
Bo Victor Thomsen
Aestas-GIS
Denmark
Den 07-03-2012 10:14, Laurence Béchet skrev:
Hi,
Thank you for the suggestion.
I did the test and of course the gpx created is not good, with a list
of error messages (not right values, like:
Error at file
C:\[...]\xerces-c-3.1.1-x86-windows-vc-10.0\bin/newtiti.gpx, line 76,
char 54
Message: value '1730878.68283692' must be less than maxExclusive
facet value '180.0'
If I start from an existing gpx file that passes the test (like
created with dnrgarmin or mapsource) and try to upload it within Qgis,
when I check the metadata of the layer property, the Layer Spatial
Reference System is not correct
*+proj=longlat *+datum=WGS84 +no_defs
If I upload in Qgis the same data created by dnrgarmin but under the
projected shapefile type, then the Layer Spatial Reference System is
correct
*+proj=tmerc* +lat_0=0 +lon_0=173 +k=0.9996 +x_0=1600000 +y_0=10000000
+ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs
*It's the general same issue: how do I force Qgis when uploading or
saving data in gpx file to use the correct Spatial reference system
(+proj)?*
How do other users do? Because I don't see the point of this software
if i cannot send my data from Qgis to my gps ...
Thank you
_______________________________________________
Qgis-user mailing list
[email protected]
http://lists.osgeo.org/mailman/listinfo/qgis-user
