[Qgis-user] vector shp from NAD83 (CSRS98) to UTM WGS84
Nicolas Cadieux
nicolas.cadieux at archeotec.ca
Thu Mar 31 07:55:24 PDT 2016
Hi Andreas,
That is very interesting. I would like to know more about these grids and how QGIS deals with it. Do you have any additional links to share?
All I can see is that the proj4 parameters for many of the CRS in North America are identical and lead to no actual changes in the coordinate unless you are going from nad27 to nad 83 or Wgs84 which is more drastic.
That is why I use the nrcan tool that can do transformation based on ITRF and WGS84 CRS.
I would be nice to do that strait in QGIS. I will look into your method and report back.
Nicolas
On Mar 31, 2016 10:24 AM, "Neumann, Andreas [via OSGeo.org] " <ml-node+s1560n5259006h47 at n6.nabble.com> wrote:
Hi Nicolas,
That is not exactly true.
QGIS can very well cope with grid-shift based transformations. This requires an adequate grid shift file (a gsb file), which should be placed in the folder share/proj
National mapping agencies typically provide these grid-shift files. As an example, our Swiss NMA provides these at http://www.swisstopo.admin.ch/internet/swisstopo/en/home/products/software/products/chenyx06.html
QGIS automatically detects whether a grid shift file is necessary for a transformation and if the appropriate gsb files is present it is used. The accuracy of the transformation then depends on the grid-shift file accuracy (resolution).
The grid shift files can be used both for reprojecting vector and raster data.
Greetings,
Andreas
On 2016-03-31 15:54, Nicolas Cadieux wrote:
Hi, It is my understanding that the parameters used in QGIS for that transformation are not sufficient and will simply lead to a change in EPGS code number with no actual changes to the coordinates.
If you are dealing with data in the 20k to 250k (like topo maps, SRTM), you can go ahead with that. Difference between both projection are basically due to continental drift and the addition of the third dimension.
For anything submeter (Lidar, high precision GPS) I recommend using a more precise software. I know that nrcan has good free tools for changing projection but I don't know if they handle anything else then points (TRX) I think. Look at the links below for more information if needed. File is included in attachment.
Nicolas
http://www.nrcan.gc.ca/earth-sciences/geomatics/geodetic-reference-systems/tools-applications/10925
https://www.google.ca/url?sa=t&source=web&rct=j&url=http://www.naref.org/transf/nad83_geomatica2006.pdf&q=csrs98%20nad83&ved=0ahUKEwiex4GHiOvLAhUEdx4KHb0NAwcQFggpMAU&usg=AFQjCNHa-HRpS8Hcc1j74dAysyxgobNY1w&sig2=RRPnudp1rMyhmKYd7vbdoA
On Mar 31, 2016 8:20 AM, "Joris Hintjens [via OSGeo.org] " <[hidden email]> wrote:
simply save the layer as a new one. "save as". you will be asked to enter the new CRS.
joris
Op 30 mrt. 2016, om 06:06 heeft Azzurra Lentini <<a href="/user/SendEmail.jtp?type=node&node=5258986&i=0">[hidden email]> het volgende geschreven:
Hallo to all,
do you know how I can transform vectorial data from NAD83 (CSRS98) to UTM wgs84?
do you think if I do with reproject it would be ok?? or what u suggest??
thanks a lot
--
Dr. Hydrogeologist AZZURRA LENTINI Expert of evaluation environmental hazards GIS application Haity Mobile Tel: 0050946057393 ++++++++++++++++++++++++++ Italy Mobile Tel.: **(39) 338 24 40 676 ++++++++++++++++++++++++++ SKYPE azzurrahydro ++++++++++++++++++++++++++ <a href="/user/SendEmail.jtp?type=node&node=5258986&i=1">[hidden email] ++++++++++++++++++++++++++ *Par respect pour l'environnement,* *n'imprimez ce mail qu'en cas d'absolue nécessité*
_______________________________________________ Qgis-user mailing list <a href="/user/SendEmail.jtp?type=node&node=5258986&i=2">[hidden email] List info: http://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: http://lists.osgeo.org/mailman/listinfo/qgis-user
_______________________________________________ Qgis-user mailing list <a href="/user/SendEmail.jtp?type=node&node=5258986&i=3">[hidden email] List info: http://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: http://lists.osgeo.org/mailman/listinfo/qgis-user
If you reply to this email, your message will be added to the discussion below:
http://osgeo-org.1560.x6.nabble.com/vector-shp-from-NAD83-CSRS98-to-UTM-WGS84-tp5258754p5258986.html
To start a new topic under Quantum GIS - User, email [hidden email] To unsubscribe from Quantum GIS - User, <a href="http://osgeo-org.1560.x6.nabble.com/template/NamlServlet.jtp?macro=unsubscribe_by_code&node=4125267&code=bmljb2xhcy5jYWRpZXV4QGFyY2hlb3RlYy5jYXw0MTI1MjY3fDYzNDQ4MjQxNg==">click here. <a href="http://osgeo-org.1560.x6.nabble.com/template/NamlServlet.jtp?macro=macro_viewer&id=instant_html%21nabble%3Aemail.naml&base=nabble.naml.namespaces.BasicNamespace-nabble.view.web.template.NabbleNamespace-nabble.view.web.template.NodeNamespace&breadcrumbs=notify_subscribers%21nabble%3Aemail.naml-instant_emails%21nabble%3Aemail.naml-send_instant_email%21nabble%3Aemail.naml" style="font:9px serif">NAML
nad83_geomatica2006.pdf (6M) Download Attachment
View this message in context: Re: vector shp from NAD83 (CSRS98) to UTM WGS84 Sent from the Quantum GIS - User mailing list archive at Nabble.com.
_______________________________________________ Qgis-user mailing list [hidden email] List info: http://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: http://lists.osgeo.org/mailman/listinfo/qgis-user
_______________________________________________
Qgis-user mailing list
[hidden email]
List info: http://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: http://lists.osgeo.org/mailman/listinfo/qgis-user
If you reply to this email, your message will be added to the discussion below:
http://osgeo-org.1560.x6.nabble.com/vector-shp-from-NAD83-CSRS98-to-UTM-WGS84-tp5258754p5259006.html
To start a new topic under Quantum GIS - User, email ml-node+s1560n4125267h38@n6.nabble.com
To unsubscribe from Quantum GIS - User, click here .
NAML
--
View this message in context: http://osgeo-org.1560.x6.nabble.com/vector-shp-from-NAD83-CSRS98-to-UTM-WGS84-tp5258754p5259013.html
Sent from the Quantum GIS - User mailing list archive at Nabble.com.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/qgis-user/attachments/20160331/ea2a000e/attachment.html>
More information about the Qgis-user
mailing list