[Qgis-user] vector shp from NAD83 (CSRS98) to UTM WGS84

[Andre Joost]

Am 01.04.2016 um 08:12 schrieb Andre Joost:
> Am 31.03.2016 um 16:55 schrieb Nicolas Cadieux:
>> 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.
>
> QGIS already uses a grid shift file internally for the conversion from
> NAD27 to WGS84. But there is not yet any grid shift file that reflects
> newer tectonic moves, like NAD83(CSRS98) would need.
>

Update: You might find some grid file resources in the following document:

<http://downloads2.esri.com/support/TechArticles/Grid-based_Transformation_Methods_for_Canada3.pdf>

HTH,
André Joost